Salivary Gland Involvement by Chronic Graft-Versus-Host Disease: Prevalence, Clinical Significance and Recommendations for Evaluation

Abstract

Although xerostomia is a commonly reported complaint in patients with chronic graft versus host disease (cGVHD), criteria for evaluating the prevalence and characteristics of salivary gland involvement have not been well defined in this patient population. Prior studies also do not make distinction between salivary and mucosal oral cGVHD. We have systematically evaluated sicca symptoms and signs in a large cohort of patients with cGVHD (N=101) using instruments widely used to study Sjogren’s Syndrome. Xerostomia was reported by 77% of the patients and was associated with xerophthalmia in all cases but one. Twenty-seven percent had salivary flow rates of ≤0.2 ml/min, 16% had rates ≤0.1 ml/min. Histopathological changes consisting of mononuclear infiltration and/or fibrosis/atrophy, were present in all patients with salivary dysfunction. Importantly, there was no correlation of salivary and oral mucosal involvement in cGVHD. Patients with cGVHD-associated salivary gland involvement had lower oral cavity-specific quality of life and body mass index. In conclusion, salivary gland involvement is a common and clinically distinct manifestation of cGVHD. Formal evaluation of salivary function using standardized criteria is necessary and may be incorporated as outcome measure in clinical trials of cGVHD.

Introduction

Chronic GVHD (cGVHD) is the single most important complication in long term survivors after allogeneic hematopoietic stem cell transplantation (1). Involvement by cGVHD of the salivary and lacrimal glands results in Sjogren’s Syndrome (SS)-like manifestations including hyposecretion of saliva and tears.

Xerostomia can be a distressing symptom, and decreased salivary flow may lead to reduced food intake, dental caries and oral mucosal infection with Candida species (2). In addition, salivary dysfunction may be associated with other, more severe manifestations of cGVHD, such as pulmonary involvement (3). Therefore, formal assessment of salivary gland dysfunction is important in overall assessment of cGVHD. Salivary gland function can be assessed using non-invasive tests, and could be used as an outcome in clinical trials.

While the prevalence of xerophthalmia post allo-HSCT has been estimated to range between 40 and 70% in various studies (4–6), the prevalence of salivary gland involvement has not been well-described (7). Often oral dryness complaints in cGVHD are reported as “oral” or “mouth” involvement, and are not distinguished from oral mucosal lesions (8). This is in part because older literature implied the pathologic changes of the minor salivary glands found in cGVHD represented a continuum of the oral mucosal lesions found in the disease. However, oral mucosal and salivary gland involvement in cGVHD bear close resemblance to autoimmune disorders affecting these tissues, specifically oral lichen planus and SS, which occur independently of each other and affect distinct patient populations. Although guidelines for evaluation of lacrimal dysfunction in cGVHD were defined in the recent NIH consensus criteria (9, 10), no recommendations have been provided for evaluation of salivary gland involvement. Therefore, the aim of this study was to systematically examine the characteristics and correlates of salivary gland function in cGVHD and determine if oral mucosal and salivary gland pathology in cGVHD occured independently. We also developed preliminary guidelines that could be used to evaluate patients with cGVHD who report oral dryness.

Patients and Methods

Patients

One hundred and one consecutive adult patients enrolled in a cGVHD cross-sectional study (clinicaltrials.gov #NCT00331968) were included in this study. The study was approved by the Institutional Review Board of the National Cancer Institute and informed consent was obtained from all participants. Patients underwent comprehensive multi-specialty clinical evaluation, laboratory testing and research sample collection, and they completed a series of patient-reported outcome measures and cGVHD diagnosis was established using NIH consensus criteria (9). The sample had a mean age of 45.9 years (S.D. ± 12, range 20–66 years), predominantly white (n=92, 91%), and with approximately equal representation of males (n=53; 52%) and females (n=48; 48%). Median time from transplant procedure to cGVHD diagnosis was 5 months (range 3–35 months). Most patients had active moderate or severe cGVHD requiring continuation of systemic immunosuppression. Transplant and cGVHD characteristics for the sample are presented in Tables 1–3.

Table 1.

Patient Characteristics (N=101)

Diagnosis, N (%)
Acute leukemia/myelodysplastic syndrome	42 (41)
Chronic leukemia	23 (23)
Lymphoma	21 (21)
Multiple myeloma	8 (8)
Aplastic anemia/myelofibrosis	5 (5)
Paroxysmal nocturnal hemoglobinuria	2 (2)
Conditioning, N (%)
Myeloablative	59 (59)
Reduced intensity	42 (41)
Donor type, N (%)
Matched sibling donor	73 (72)
Matched unrelated donor	28 (28)
Stem Cell Source, N (%)
Bone Marrow	19 (19)
Peripheral Blood	80 (79)
Unknown	2 (2)
Karnofsky Performance Status, Mean (SD), Range	81 (12), 30–100
Months Since Transplant, Mean (SD), Range	43 (38), 4–201
Months Since cGVHD Diagnosed, Mean (SD), Range	36 (37), 1–196

Table 3.

Prevalence of cGVHD Organ System Involvement Based on NIH Scoring

	Salivary Dysfunction
Organ System Involved, N (%)	Present (N=19)	Absent (N=52)
Skin	13 (68)	41 (79)
Oral Cavity (any manifestation)	18 (95)	37 (71)
Eyes	18 (95)	40 (77)
Lungs	10 (53)	26 (51)
Liver	9 (47)	25 (48)
GI Tract	11 (58)	17 (33)
Joints/Fascia	8 (42)	29 (56)
Genital Tract (women only)	7 (50)	13 (41)
Total number of organ systems involved, median (range)	4.5 (3–7)	4.0 (2–8)

Clinical Evaluations

Salivary and lacrimal symptoms were evaluated using methods described in American-European Consensus Group (AECG) for SS (11). The presence of xerostomia and xerophthalmia were determined with the three-item AECG screening questionnaire, which assesses both presence and duration of symptoms. It has been previously reported that patient reported symptoms of dry mouth do not correlate well with objective measures of salivary function (12). In addition, xerostomia severity was graded with 0–10 patient reported scale.

Evaluation of salivary gland function was performed by measurement of the whole unstimulated salivary flow rate using five minute saliva collection into a pre-weighed 50 cc centrifuge tube (modified from reference (13). Objective evaluation of lacrimal function included Schirmer test (performed with local anesthesia) and evaluation of keratopathy and conjunctival involvement by fluorescein and lissamine green staining according to European-US criteria for evaluation of SS (11). Schirmer test of ≤5mm in 5 min was considered abnormal.

Oral mucosal changes were evaluated with a scale developed for scoring oral mucositis lesions and oral lichen planus – a condition clinically very similar to oral cGVHD (14).

Oral cavity-specific quality of life (the impact of an oral health condition on talking, eating, self-esteem, mood, and role function) was assessed with 14 item questionnaire OHIP-14 that has been validated in a number of oral conditions (15). Health-related quality of life (HRQL) and selected aspects of cGVHD symptom bother were assessed with FACT-G questionnaire (16), and single items drawn from the Lee cGVHD symptom scale (17), respectively. Overall and organ specific cGVHD severity were assessed based on detailed multidisciplinary clinical and diagnostic evaluation of the skin, mouth, eyes, liver, lungs, gastrointestinal system, functional capacity, and gynecologic disease manifestations in women. Scoring of individual organ systems was based on the NIH criteria for diagnosis and staging (9). Using objective criteria, organ system sub-specialists graded the severity of cGVHD in each of eight organ systems and a summated severity score ranging from 0–100 was calculated.

Histopathology

Minor salivary glands (MSG) were collected from lower lips of consenting patients using a standard procedure (18), fixed in formalin and embedded in paraffin. H&E stained sections were evaluated by a pathologist with expertise in chronic GVHD and SS who was blinded to clinical evaluation results. Degree of mononuclear infiltration was assessed by focus score (number of lymphocytic foci of 50 or more cells per 1 mm² of the minor salivary gland section) and Greenspan grade (0–4 scoring of the infiltrate density) (19). Glandular atrophy and fibrosis were separately scored on a 0–3 scale, based on the proportion, by thirds, of glandular parenchyma affected. The presence or absence of peri-lobular fibrosis, duct rupture and ductitis were also recorded.

Statistical methods

A Chi-squared test or Fisher’s exact test was used to evaluate differences in proportions as appropriate. Group differences were assessed using a Wilcoxon rank sum test for continuous variables and exact Cochran-Armitage test for ordered and categorical variables. ANCOVA was used to identify the strength of the association between outcomes of interest while controlling for the effects of other parameters that may impact the findings. Correlations between two continuously measured parameters were determined using the Spearman rank correlation coefficient, r, with the interpretation of the strength of the association between parameters as follows:

• |r| >0.70 indicates a strong correlation

• 0.50 < |r| < 0.70 indicates a moderately strong correlation

• 0.30 < |r| < 0.50 indicates a weak to moderately strong correlation

• |r| < 0.30 indicates a weak correlation

All p-values are two tailed and presented without formal adjustment for multiple comparisons. However, in view of the exploratory nature of the study, the varying degrees of independence among the tests, and the number of tests performed, a p-value <0.005 may be considered a statistically significant result, while results for which 0.005 < p <0.05 would be considered strong trends.

All calculations were performed on MedCalc version 9.3.0.0 statistical software (Mariakerke, Belgium) and SPSS for Windows (version 15.0, SPSS Inc., Chicago, USA).

Results

Prevalence of salivary and lacrimal dysfunction in cGVHD patients

A summary of clinical parameters is presented in Supplemental table 1. Seventy eight patients (77%) completed the 6 item SS questionnaire. Overall, sixty six patients (86%) gave at least one positive answer on the questionnaire with sixty (77%) patients reporting oral and fifty one (67%) patients reporting ocular complaints. There was a significant association between symptoms of ocular and oral dryness with 46 patients (59%) reporting both complaints (chi-square for number of patients with ocular or oral complaints, p=0.0017).

We then evaluated lacrimal and salivary function using clinician-assessed measures. Based on the recommendations of the NIH consensus criteria on cGVHD diagnosis and staging (9, 10), we considered an abnormal Schirmer tear test and/or the presence of keratopathy in at least one eye as the definition of decreased lacrimal function. Decreased salivary gland function was defined as the unstimulated salivary flow rate of less than 1 ml in 5 min (0.2 ml/min), a value consistent with the lower limit of normal salivary function as determined by population studies (20)

Using these criteria, salivary dysfunction was less prevalent [27% (22 of 81)] than lacrimal dysfunction [82% (80 of 98)] in our cGVHD cohort. Seventy two patients of 98 for whom the results were available had Schirmer tear test of 5mm or less (73%). Keratopathy as established by positive corneal staining was found in 57 out of 98 (58%) subjects. As expected, severity of keratopathy correlated with Schirmer tear test values (r=−0.52, p<0.001). All but one patient with salivary dysfunction also had lacrimal dysfunction.

We also examined the correlation of objective measures of salivary and lacrimal flow and patients’ symptoms. There was a moderately good correlation between self-reported xerostomia and salivary flow rate (r=−0.51, p<0.001). Similar correlation was found between patient reported ocular dryness and Schirmer test results (r=−0.55 and −0.52, for the left and right eye respectively, p<0.001).

An easily administered screening test would be useful to guide subsequent evaluation of lacrimal and salivary gland function in cGVHD. We therefore evaluated the predictive ability of the Sjögren’s Syndrome questionnaire (SSQ) with regard to decreased salivary and/or lacrimal function on clinical testing. Seventy six patients had both patient reported and clinician-assessed evaluations of salivary and lacrimal function. Fifty four out of 64 patients with lacrimal dysfunction and 5 out of 12 patients with normal eye exam endorsed at least one of the three ocular items from the SSQ (sensitivity=84%, specificity=58%, positive predictive value [PPV]=92%, negative predictive value [NPV]=41%). Out of 21 patients with low salivary flow rates, 19 had responded positively to at least one item on SS questionnaire. Among 55 patients with clinically normal salivary flow rates, 23 had a negative questionnaire (sensitivity=90%, specificity=42%, PPV=37%, NPV=92%). These data suggest that eye component of the questionnaire may be most useful to rule in patients likely to have positive findings on the ophthalmologic exam while oral component would be most useful to rule out significant salivary flow reduction. However, predictive values reported here should be interpreted with caution as the prevalence of lacrimal and salivary gland dysfunction in our study may be higher than those in the general cGVHD/allo-HSCT population.

Lack of association between salivary gland dysfunction and oral mucosal disease

To explore the hypothesis that salivary gland and mucosal involvement represent distinct manifestations of cGVHD, we evaluated the covariation between the presence and severity of mucosal involvement and salivary gland dysfunction in our cohort. Out of 75 patients for whom both data points were available for analysis, only 14 had both salivary gland dysfunction and oral mucosal involvement. Forty one patients had only mucosal and 5 only salivary gland dysfunction. Fifteen patients had neither mucosal involvement nor salivary dysfunction (Fisher exact test for proportions of patients with mucosal and/or salivary involvement, p=1.0). There was no correlation between the degree of mucosal changes as measured by specific grading scale and salivary flow rate (r=0.09, p=0.42). Similarly, there was no difference in cGVHD oral mucosal severity score between patients with (median 4.5, 25–75 percentile 0.25–6.0, N=19) and without salivary gland dysfunction (median 3.5, 25–75 percentile 0–9.8, p=0.93, N=56) or in salivary flow rates between patients with (median 0.36 ml/min, 25–75 percentile 0.20–0.67 ml/min, N=55) and without mucosal disease (median 0.35 ml/min, 25–75 percentile 0.20–0.59 ml/min, N=20, p=0.59). These findings suggest that salivary and oral mucosal involvement with cGVHD are distinct disease manifestations and not extensions of one another.

Salivary gland dysfunction is associated with impairment in oral cavity-specific quality of life and decreased BMI

We used a validated oral cavity-specific quality of life questionnaire (OHIP-14) to evaluate the impact of salivary gland dysfunction on the oral quality of life of patients with cGVHD. OHIP-14 scores were significantly higher (indicating more impairment in quality of life) in patients with salivary gland dysfunction (median 12, 25–75 percentile 10–29, N=21 vs. median 6.5, 25–75 percentile 1–13, N=54, p<0.001). In addition, greater impairment in oral cavity-specific quality of life was associated with more perceived oral dryness (r=0.49, p<0.001) and lower salivary flow rates (r=−0.41, p<0.001). Surprisingly, we found no statistically significant difference in OHIP-14 scores between patients with and those without oral mucosal cGVHD (median 10, 25–75 percentile 3–17, N=51 vs. median 6.5, 25–75 percentile 1–10, N=20, p=0.19). Furthermore, although quality of life scores correlated well with the degree of oral discomfort (r=0.43, p<0.001), they were not associated with the clinician-assessed severity of oral mucosal disease (r=0.21, p=0.09). Although other oral conditions such as caries or periodontal disease could have impacted oral quality of life scores such changes were not commonly observed in our patient cohort.

There was no statistically significant relationship between the presence of salivary gland dysfunction and overall HRQL as assessed by FACT-G, a global health related quality of life scale, controlling for age and cGVHD severity (p=0.193). However, salivary dysfunction may result in impaired nutritional status. Participants with salivary gland dysfunction reported significantly greater difficulty with swallowing solid foods (p=0.001) on the Lee cGVHD symptom scale. After adjusting for cGVHD severity, patients with salivary involvement also had significantly (p=0.008) lower BMI than those with intact salivary flow rates (estimated marginal mean BMI was 21.9, 95% CI 19.6–24.2, N=22 vs estimated marginal mean BMI 25.3, 95% CI 24.1–26.6, N=59). These differences in BMI remained when we adjusted specifically for the severity of cGVHD GI manifestations (p=0.001). There was no difference in BMI between groups with and without GI symptoms (mean BMI 24.2, 95% CI 20.8–27.6, N=19 vs mean BMI 25.1, 95% CI 24.0–26.2, N=79, p=0.51).

Histopathological changes in patients with salivary gland dysfunction

Minor salivary gland tissue was available from 36 patients, Six patients did not have complete clinical information and were therefore excluded. On gross examination, features such as periductal infiltration (Fig. 1A), atrophy of salivary gland lobules and periglandular fibrosis (Fig. 1B) were commonly observed. In some patients, atrophy was so severe that no minor salivary gland tissue could be identified.

Figure 1.

A - Photomicrograph of a salivary gland that shows Sjogren’s like periductal inflammation. There is a periductal infiltrate composed predominantly of lymphocytes (H&E, 200x). B - Severe atrophy with interstitial fibrosis. Most of the mucinous acinar parenchyma has been lost from this lobule, replaced by ductular metaplasia and increased peri-lobular adipose tissue. There is a mild, predominant lymphocytic infiltrate in the fibrous interstitium. (H&E, 200x)

Patients with clinically observed salivary gland dysfunction had higher atrophy (median 2, 25–75 percentile 0.5–3.0, N=8 vs median 0.5, 25–75 percentile 0–2.0, N=22, p=0.16), fibrosis (median 2, 25–75 percentile 0.5–3.0, N=8 vs median 0, 25–75 percentile 0–2.0, N=22, p=0.12) and focus scores (median 0.50, 25–75 percentile 0–2.5, N=8 vs median 0, 25–75 percentile, 0–1.0 N=22) although the differences did not reach statistical significance. There was a difference in Greenspan grade (median 2.5, 25–75 percentile 2.0–4.0, N=8 vs median 2, 25–75 percentile 1.0–3.0, N=22, p=0.04). The group of patients with Greenspan grade >1 had lower salivary flow rates (median 0.24 ml/min, 25–75 percentile 0.16–0.43 ml/min, N=21 vs median 0.51 ml/min, 25–75 percentile 0.38–0.64 ml/min, N=9, p=0.02). This group also included only patients with salivary gland dysfunction as defined by our flow rate criterion, while all patients without salivary gland dysfunction had Greenspan grade ≤1.

Currently, there is no agreement on how to evaluate and report minor salivary gland involvement based on histopathological grading. We propose a composite histopathological grading score of Greenspan grade and degree of fibrosis as a tool to evaluate overall involvement of minor salivary glands. Greenspan grade reflects the degree of infiltration in the glands, and fibrosis and atrophy are indicative of long term damage. In this subject cohort, atrophy was highly correlated with fibrosis (r=0.96, p<0.001) and, therefore, would not have added information to the overall score. Mild infiltration and minor degrees of fibrosis are non-specific and become more prevalent with ageing (21). Indeed, in our sample age did correlate with degree of the glandular fibrosis (r=0.59, p=0.005). We therefore propose the cutoff of ≥3 for the composite score to indicate likely involvement with cGVHD.

If composite MSG score of 3 or more is used as an indicator of salivary gland cGVHD, 100% of patients with salivary flow rate ≤0.2 ml/min will have histopathological evidence of minor salivary gland involvement. However, 60% of patients with histological evidence of minor salivary gland disease in our sample had normal salivary flow rates.

Factors associated with salivary dysfunction in cGVHD

In order to better understand the factors contributing to salivary dysfunction in cGVHD we evaluated the association of various demographic and transplant-related variables with the presence of salivary gland dysfunction. In a multivariable model, none of the demographic and transplant parameters examined, including age, intensity and type of the conditioning regimen (myeloablative vs non-myeloablative, use of total body irradiation), type of donor (matched related vs unrelated or haploidentical), severity of oral mucosal cGVHD, or time post cGGVHD diagnosis was predictive of salivary gland dysfunction (data not shown).

Salivary gland involvement is commonly observed in patients with scleroderma and in these patients decreased salivary gland function has been linked to the glandular fibrosis (22). Since sclerodermatous skin involvement is the hallmark of chronic GVHD we hypothesized that skin sclerosis in cGVHD may be associated with salivary gland involvement. We found no association between sclerotic skin involvement (superficial or deep) and salivary dysfunction in our cohort (Fisher exact test, p=0.81). There were no differences in mean salivary flow rates or degree of salivary gland fibrosis in patients with or without sclerotic skin involvement (data not shown).

Saliva contains numerous factors important for innate and adaptive mucosal immunity including secretory IgA. Salivary dysfunction may predispose to oral colonization and subsequent recurrent pulmonary infections (23). Furthermore, sicca symptoms have been reported in association with pulmonary involvement in cGVHD (3). Using NIH cGVHD lung scores (a score that ranges from 0–3), we observed a trend for salivary gland dysfunction to be associated with greater levels of pulmonary cGVHD involvement (Cochran-Armitage exact test, N=81, p=.015).

Laboratory parameters in cGVHD patients with sicca syndrome

Autoantibodies are commonly associated with and are used for diagnostic purposes in many autoimmune conditions. Antibodies to nuclear antigens Ro (SSA) and La (SSB) are found in a high percentage of patients with SS (11). Although we detected a wide range of autoantibodies in our patient cohort, the individual prevalence was very low. For example, there were only 4 patients with positive ENA (extractable nuclear antigen) screen, a test for all intranuclear antigens used in rheumatology that includes Ro/SSA and La/SSB (Supplemental table 2).

Discussion

This is the first study to date to comprehensively analyze clinical and pathological features of sicca syndrome in cGVHD using tools used widely in the studies of lacrimal and salivary gland dysfunction in SS. We found that the prevalence of sicca complaints is extremely high in cGVHD patients and there was a significant association between complaints of xerophthalmia and xerostomia. Salivary and lacrimal glands share a common developmental origin and it is possible that similar or identical antigens in both organs are recognized by alloreactive T cells. However, it is also possible that our estimate of prevalence exceeds that in the general cGVHD population due to a referral bias as the overwhelming majority of patients in our study had moderate or severe cGVHD.

In the prospective studies of cGVHD, oral cavity is the second most commonly involved area (5). However, it is unclear whether the symptoms observed are due to mucosal (i.e. lichen planus-like) disease or salivary gland involvement. In fact, in the older (7, 24) and more recent (25) publications dealing with diagnosis and staging of oral cGVHD, mucosal and minor salivary gland biopsy are advocated as equivalent diagnostic tests. Although criteria for clinician-assessed lacrimal gland involvement have been defined by the recent NIH consensus guidelines, salivary and mucosal involvement were grouped as “oral” involvement (9, 10). However, such grouping of mucosal and salivary gland involvement may be counterproductive, as salivary gland disease and mucosal diseases are managed differently. For example, while topical anti-inflammatory agents are commonly used for superficial mucosal inflammation, topical therapy is unlikely to be effective for salivary gland involvement. Patients with significant decreases in salivary gland output often benefit from cholinergic agonists, such as pilocarpine.

Our data for the first time provide evidence of an important distinction between salivary and oral mucosal involvement with cGVHD as demonstrated by lack of correlation between symptoms and signs related to each subset. This is demonstrated by no difference in salivary flow rates between patients with and without mucosal disease and no correlation between severity of oral mucosal disease as assessed by standardized grading and flow rate measurements. Indeed, patients with mucosal involvement had higher mean flow rates. The major clinical significance of salivary gland dysfunction is demonstrated by the greatly decreased oral cavity–specific quality of life in patients with xerostomia. In fact, salivary dysfunction had a much greater impact on oral cavity-specific quality of life scores than did mucosal disease. While there was no significant association between salivary dysfunction and overall HRQL when cGVHD severity and age were controlled, the importance of salivary function for nutritional status is underscored by lower BMI values in patients with salivary involvement and significantly greater reported difficulty swallowing solid foods. Our results suggest that salivary gland dysfunction may explain in part the observed association between cGVHD and weight loss (26).

Since no guidelines exist for assessment of salivary gland function in cGVHD we adapted methods recommended for evaluation of salivary function in SS (11). We propose using SS questionnaire as initial screening test of salivary dysfunction that can be performed at each visit in the context of screening for cGVHD. In addition, quantitative evaluation of xerostomia on a 0–10 scale should be performed in all patients. In patients with positive response to the questionnaire measurement of whole unstimulated salivary flow rate can be performed as objective evaluation of salivary gland function. This test does not involve any special equipment apart from pre-weighed or graduated plastic tube, is reliable and can be easily performed by non-specialists with minimal training. We have chosen a cut-off of 0.2 cc/min as the lower limit of normal based on the flow rates in the large cohorts of normal volunteers (20). While 0.1 cc/min recommended by the SS consensus criteria is very specific for salivary gland involvement by SS, it is not sufficiently sensitive for use in cGVHD population and will miss many patients with early disease.

We propose a composite score of mononuclear infiltration and fibrosis as a histopathological criterion of minor salivary gland involvement with cGVHD. Fibrosis and lymphocytic infiltration are included in two other scales developed to evaluate cGVHD minor salivary glands, but the scales are limited quantitatively, or the score is based on combined mucosal and salivary changes (27–29). In our cohort, all patients with salivary flow rates below 0.2 cc/min had positive findings on biopsy (MSG score ≥3). Although this finding needs to be validated in a prospective study, such patients probably do not need a minor salivary gland biopsy for confirmation of the salivary gland involvement. However, minor salivary gland biopsy and probably testing of the functional reserve of the salivary glands by measurements of stimulated salivary flow rates may be useful to identify patients who are most likely to benefit from treatment. In our opinion, patients late in the disease process as manifested by the extensive destruction of the minor salivary gland tissues with fibrosis and atrophy are probably unlikely to regain significant function. Conversely, patients with lymphocytic infiltration but minimal salivary gland destruction are probably the most likely to benefit from immunosuppressive treatment.

The significance of positive histopathology as a “gold standard” for salivary gland involvement is unclear particularly in asymptomatic patients. While positive findings are probably sufficient evidence for the alloreactive response to salivary gland tissues it is not known whether such involvement would necessarily progress to symptomatic disease. Similarly, it is not known whether treatment would reverse the salivary gland pathology and at what points such treatment would be most effective. In this sense, using objective parameters of salivary function could be useful to define patients who might benefit most from treatment and who are most at risk for xerostomia related complications. These hypotheses could be tested in the future therapeutic trials and natural history studies.

Although the clinical manifestations of lacrimal and salivary gland injury are similar in chronic cGVHD and SS significant differences exist. For example, the prevalence of autoantibodies in our study has been very low overall and autoantibodies associated with the SS (anti-SSA) were detected in only one patient. Similarly, the pattern of salivary gland histology is different in SS where lymphocytic infiltration is much more pronounced leading to a higher focus scores (19). This could be explained by the different pathogenetic mechanisms involved and requires further study at the cellular and molecular level.

Sicca syndrome is a common manifestation in scleroderma patients and it has been proposed that pathologic changes in the salivary glands are a part of generalized fibrotic process in scleroderma (22). Because sclerodermatous skin involvement is a common feature of cGVHD we evaluated the hypothesis that these two manifestations could be linked. Although fibrosis is a prominent histopathological feature of salivary gland disease, we found no association between skin sclerosis and sicca syndrome, suggesting that skin and salivary/lacrimal glands are independently affected in cGVHD.

Our study did not find an association between the salivary gland dysfunction in cGVHD and a number of patient or transplant characteristics such as age or intensity of the conditioning regimen. Although some previous studies have linked total body irradiation to subsequent sicca manifestations (30, 31) our study did not confirm such association. Indication of higher degree of impairment in pulmonary function in patients with salivary gland dysfunction is intriguing and requires further study. At least one study reported of the association of sicca syndrome and pulmonary involvement post allo-HSCT (3). Unfortunately, no precise definition of the sicca syndrome was given, complicating interpretation of the results.

There are several limitations to this study. The population studied includes primarily patients with long standing and more severe disease with the mean disease duration of about 3 years. The data collected represents a cross sectional representation of the condition with very diverse and complex manifestations. The findings presented may not be directly applicable to routine care of a general cGVHD patient population. Nevertheless, we believe that this work lays a foundation for a comprehensive assessment of the salivary component of cGVHD in the research setting. Further refinements to the guidelines proposed must be made in the context of the prospective studies and controlled clinical trials.

In conclusion, salivary gland involvement by cGVHD contributes significantly to morbidity and impaired quality of life in this patient population. Our results demonstrate the distinction between salivary and oral mucosal involvement, and specific criteria for assessment of salivary gland involvement in cGVHD are proposed. Prospective studies are necessary to validate our findings and address issues of optimal timing and nature of therapeutic intervention to prevent and ameliorate the loss of salivary gland function in cGVHD.

Table 2.

Chronic GVHD Characteristics (N=101)

	Salivary Dysfunction
	Present (N=22)	Absent (N=59)
Chronic GVHD onset, N (%)
De novo	10 (45)	21 (36)
Quiescent	2 (9)	13 (22)
Progressive	10 (45)	25 (42)
Platelets ≤ 100,000, N (%)	5 (23)	4 (7)
Clinician global rating of cGVHD, N (%)
Mild	0 (0)	2 (3)
Moderate	8 (36)	24 (41)
Severe	11 (50)	26 (44)
Missing	3 (14)	7 (12)
Change in chronic GVHD over past month, N (%)
Better	5 (23)	10 (17)
About the same	9 (41)	18 (31)
Worse	8 (36)	31 (53)
Intensity of current immunosuppression, N (%)
None	3 (14)	5 (8)
Mild*	2 (9)	6 (10)
Moderate**	9 (41)	16 (27)
High***	8 (36)	22 (59)
Chronic GVHD Clinical Severity Score, 0–100, Mean (SD), Range	37 (10), 19–56	30 (9), 7–48
Lee cGVHD Symptom Scale Total Score, 0–100, Mean (SD), Range)	34 (14), 11–69	25 (13), 1–60

^*single agent prednisone <0.5 mg/kg/day

^**single agent prednisone ≥ 0.5 mg/kg/day or single agent/modality+/− prednisone ≥ 0.5 mg/kg/day

^***2 or more agents/modalities +/− prednisone ≥ 0.5 mg/kg/day

Abbreviations

AECG

American-European Consensus Group

allo-HSCT

allogeneic hematopoietic stem cell transplantation

ANA

antinuclear antibodies

ANCOVA

analysis of covariance

BMI

body mass index

c-ANCA

c-antineutrophil cytoplasmic antibodies

CCP

cyclic citrullinated peptide

cGVHD

chronic graft versus host disease

ENA

extractable nuclear antigen

H&E

hematoxylin-eosin

HRQL

health-related quality of life

MSG

minor salivary glands

RPR

rapid plasma reagin

RNP

ribonucleoprotein

RF

rheumatoid factor

SS

Sjogren’s Syndrome

SSA

Sjogren’s Syndrome A

SSB

Sjogren’s Syndrome B

SSQ

Sjögren’s Syndrome questionnaire

TBI

total body irradiation

WUFR

whole unstimulated salivary flow rate