Abstract
The Epstein-Barr virus (EBV) is a ubiquitous lymphotropic herpesvirus that infects the human body through the respiratory tract. Usually, primary infection with EBV is asymptomatic and occurs early in life, however adolescents or young adults are more likely to develop a self-limited symptomatic infection, which manifests as acute infectious mononucleosis (IM). Systemic EBV-positive lymphoproliferative disease (EBV + T/NK-LPD) has been described as a disease related to chronic or persistent EBV infection after acute EBV infection, with severe IM-like symptoms. EBV + T/NK-LPD is associated with high mortality and morbidity with life-threatening complications. Information on its prognostic factors remains limited, therefore in this study, we aimed to evaluate the association between prognostic factors and mortality and complications of EBV + T/NK-LPD in China by retrospectively reviewing 173 EBV + T/NK-LPD cases. We observed that the high mortality rate of EBV + T/NK-LPD was mainly due to serious and fatal complications. Fever, lymphadenopathy, hepatosplenomegaly, EBV-encoded RNA (EBER) > 50/HPF, Ki-67 > 30%, and other visible complications were closely associated with EBV + T/NK-LPD prognosis. In addition, fever, hepatosplenomegaly, decreased WBC count, and a Ki-67 index of > 30% were risk factors for complications. Thus, disease prognosis should be based on a comprehensive analysis of pathological and clinical data. Such data will help pathologists and clinicians to pay close attention to the changes in the clinical condition of the patients as well as take precautionary measures against the occurrence of fatal complications.
Keywords: Epstein-Barr virus, proliferative disease, T/NK cell, prognostic factor
Introduction
Epstein-Barr virus (EBV) is a ubiquitous lymphotropic herpesvirus that infects the human body through the respiratory tract [1,2]. Usually, primary infection with EBV is asymptomatic and occurs early in life. However, adolescents or young adults are more likely to develop a self-limited symptomatic infection, which manifests as acute infectious mononucleosis (IM) [3-6]. Systemic EBV-positive lymphoproliferative disease (EBV + T/NK-LPD) has been described as a disease related to chronic or persistent EBV infection lasting longer than 6 months after acute EBV infection, with severe IM-like symptoms, elevated antibody titers against EBV, and evidence of organ damage without evidence of any underlying immunodeficiency. The term EBV + T/NK-LPD encompasses a broad spectrum of diseases, including a systemic polyclonal, oligoclonal, or often monoclonal T-cell or natural killer (NK)-cell lymphoproliferative disease that exhibits varying degrees of clinical severity depending on the host immunity and EBV factor [7], as well as cutaneous manifestations, such as hydroa vacciniforme-like T/NK lymphoproliferative disease (HV-T/NK-LPD) and hypersensitivity to mosquito bites (HMB) [8-11]. Park et al. [12] reviewed the clinical and laboratory features of EBV + T/NK-LPD and showed that the disease had high mortality and high morbidity with life-threatening complications [12]. However, studies on its prognostic factors are limited. Therefore, to analyze the prognostic factors for this condition in patients in China, we retrospectively reviewed 173 cases of EBV + T/NK-LPD in this study.
Materials and methods
Case selection
A total of 173 EBV + T/NK-LPD cases were retrospectively obtained from the database of the Department of Pathology, Beijing Friendship Hospital, Capital Medical University (at the Lymphoma Diagnosis and Research Center, Institute of Beijing Clinical Medicine). All cases were received for consultation between August 2002 and May 2016. The latest follow-up was on April 6, 2017. Of them, 135 cases with systemic EBV + T/NK-LPD, 20 cases with HV-T/NK-LPD, 10 cases with HMB, 8 cases with other types of EBV + T/NK-LPD, affecting different parts of the body different locations were included.
Clinical and pathological factors
The clinical and pathological data included sex, age, disease course, symptoms (e.g., fever, lymph node enlargement, and hepatosplenomegaly), white blood cell count (WBC) count, platelet (PLT) count, EBV-encoded RNA (EBER) count, Ki-67 index, EBV-infected cell type, types of EBV + T/NK-LPD and their associated complications, follow-up time, and whether or not death was an outcome.
Patient criteria
Diagnosis of EBV + T/NK -LPD relies on the confirmation of chronic or persistent EBV infection of T or NK cells and is defined as a severe illness lasting more than 3 or 6 months, with the following clinical and laboratory evidence: (i) primary EBV infection or markedly abnormal EBV antibody titers (e.g., anti-EBV viral capsid antigen IgG ≥ 640, anti-EBV early-antigen IgG ≥ 160, and anti-EBNA < 2); (ii) major organ involvement such as interstitial pneumonia, hypoplasia of the bone marrow, uveitis, lymphadenitis, persistent hepatitis, and splenomegaly; and (iii) increased EBV RNA or protein levels in affected tissues [7,13].
Immunophenotypic analysis
MaxVisionTM 2 kit (catalog No. KIT-5910/5931) and monoclonal antibodies, including CD20, CD3, CD2, CD5, CD4, CD8, CD56, CD30, Granzyme B, TIA-1, Ki-67, provided by Maixin Biotech (Fuzhou, China), were used for the detection of all relevant antigens. The pretreatment methods as well as primary antibodies and their working dilutions used in this study are listed in Table 1.
Table 1.
Primary antibodies and conditions used for immunohistochemical staining
| Antigen | Clone | Dilution | Antigen Retrieval Agent | Manufacturer |
|---|---|---|---|---|
| CD20 | L26 | 1:200 | HP EDTA* | Maixin Biotech |
| CD2 | AB75 | 1:50 | HP EDTA | Maixin Biotech |
| CD3 | SP7 | 1:50 | HP EDTA | Maixin Biotech |
| CD5 | SP19 | 1:50 | HP EDTA | Maixin Biotech |
| CD4 | SP35 | 1:80 | HP EDTA | Maixin Biotech |
| CD8 | SP16 | 1:100 | HP EDTA | Maixin Biotech |
| CD30 | Ber-H2 | 1:20 | HP EDTA | Maixin Biotech |
| CD56 | 56C04 | 1:100 | HP EDTA | Maixin Biotech |
| Ki-67 | MIB-1 | 1:200 | HP EDTA | Maixin Biotech |
| Granzyme B | GZB01 | 1:50 | HP EDTA | Maixin Biotech |
| TIA-1 | TIA-1 | 1:25 | HP EDTA | Maixin Biotech |
HP EDTA: EDTA (1 mM, pH 9.0) boiled under high pressure.
In situ hybridization of EBV
The EBV Probe In Situ Hybridization Kit (Triplex International Biosciences, China, Co. Ltd.) was used to detect EBERs according to the following steps: (1) deparaffinization and dehydration of the paraffin sections using xylene and a series of graded ethanol; (2) pretreatment with proteinase K for 5 min; (3) hybridization with digoxigenin-conjugated EBV (EBERs) probe at 37°C for 4 h; (4) signal detection using peroxidase-conjugated anti-digoxigenin antibody and 3,3’-diaminobenzidine; and (5) counterstaining of sections with hematoxylin solution. The positive signals were brownish yellow and localized within the nuclei. A known EBER-positive case of extranodal NK/T-cell lymphoma and a EBER-negative case of lymphoid hyperplasia of the tonsil were designated as positive and negative controls, respectively.
Statistical analysis
Statistical analysis was performed using SPSS for Windows Version 19.0. Either the χ2 or the Fisher’s exact test (single-sided) was used to compare categorical variables in univariate analysis. Logistic regression analysis was performed for multivariate analysis. The Kaplan-Meier estimation method and the log-rank test were used for survival analysis. A P value of < 0.05 was considered statistically significant for all analyses.
Results
Clinical findings
Systemic EBV + T/NK-LPD
Ninety-three male patients and 42 female patients (male-to-female ratio of 2.2:1) were diagnosed with this disease. The patients were aged between 1 and 75 years, with a median age of 20 years. The disease course duration ranged between 1 and 84 months, with a median of 6 months. There were 108 cases of fever (80.0%), 108 cases of lymphadenopathy (80.0%), and 85 cases of hepatosplenomegaly (63.0%).
HV-T/NK-LPD
Eleven male patients and nine female patients (male-to-female ratio of 1.2:1) were diagnosed with this condition. The age of these patients ranged from 2 to 47 years, with a median age of 7.5 years. The disease course duration was 2 to 540 months, with a median of 30 months. There were 18 cases of fever (90.0%), 6 cases of lymphadenopathy (30.0%), and 9 cases of hepatosplenomegaly (45.0%).
HMB
Seven male patients and three female patients (male-to-female ratio of 2.3:1) were diagnosed with this condition. These patients were aged between 4 and 28 years, with a median age of 8 years. The duration of the disease course was between 1 and 84 months, with a median of 27 months. There were 9 cases of fever (90.0%), 5 cases of lymphadenopathy (50.0%), and 3 cases of hepatosplenomegaly (30.0%).
Other EBV + T/NK-LPD-affected locations
Six patients were men and two were women (male-to-female ratio of 3:1). These patients were aged between 6 and 52 years, with a median age of 15 years. The disease course duration was between 3 and 108 months, with a median of 17.5 months. One lesion was located in the skin, and manifested as a large skin ulcer; a solitary mass lesion was detected in the stomach, causing intermittent epigastric pain; four cases of intestinal EBV + T/NK-LPD along with abdominal pain, diarrhea, and ulcer development were detected. The gum was affected in two cases, and these patients developed a mucosal ulcer. Four cases (of eight cases) of fever (50%) were noted.
Histopathological findings of representative patients
The morphological characteristics in EBV + T/NK-LPD have a wide spectrum. The lymph node structures ranged from being normal to completely distorted, and the cells were normal to highly atypical (Figure 1). In different areas, the morphological characteristics were different. The cellular composition was complex, including large, medium, and small cells mixed with eosinophilic granulocytes, plasma cells, tissue cells, and immunocytoid cells. T/NK cells are often located in the liver sinus and were small, with no apparent atypia observed in cases where the liver was affected (Figure 2). In cases of spleen involvement, the splenic white pulp was significantly reduced, but the red pulp area was wide. There were visible multifocal blue-stained nodules in the red pulp, which mainly consisted of small lymph nodes scattered in the center of large atypical lymphoid cells (Figure 3). In cases of bone marrow involvement, the hematopoietic and adipose tissues were significantly reduced between the trabeculae, and there was a diffused distribution of atypical lymphocytes (Figure 4).
Figure 1.
Histopathology of the lymph nodes. A. The lymph node architecture was normal (H&E, 40×). B. The cells were normal (H&E, 400×). C. Tissues stained positive for CD3 (H&E, 100×). D. Small cells tested positive for EBER (H&E, 100×). E. The structures were completely destroyed (H&E, 40×). F. The cellular components, including large, medium, and small cells, are mixed with eosinophilic granulocytes and plasma cells. Large cells were highly atypical (H&E, 400×). G. Large cells showed the presence of CD3 antigen (H&E, 100×). H. Large cells were positive for EBER (H&E, 100×).
Figure 2.
Histopathology of the liver. A. The structures were partially damaged (H&E, 40×). B. The atypical cells were often located in the liver sinus and are small in size and showed no apparent atypia (H&E, 400×). C. Small cells were positive for EBER (H&E, 100×).
Figure 3.
Histopathology of the spleen. A. White pulp was significantly reduced, but red pulp was widened (H&E, 40×). B. There were visible multifocal blue-stained nodules in the red pulp, which consisted of small lymph nodes mainly scattered in the middle of the larger atypical lymphoid cells (H&E, 400×). C. Medium and small cells were positive for EBER (H&E, 100×).
Figure 4.
Histopathology of the bone marrow. A. The hematopoietic and adipose tissues were significantly reduced between the trabecular, and atypical lymphocytes were diffuse (H&E, 40×). B. Atypical cells were positive for EBER (H&E, 100×).
Immunophenotypic analysis and in situ hybridization
All cases showed the presence of CD3 antigen, cytotoxic molecules, and EBER-positive cells in lesion areas, while 37 cases showed the presence of CD56 antigen in the same areas, indicating an NK cell phenotype. Of 49 cases, < 30% were positive for Ki-67, and of 114 cases, > 50% tested positive for this antigen. The number of EBER-positive cells was < 50/HPF in 54 cases and > 50/HPF in 119 cases.
Outcomes at follow-up
Sixty-five patients (37.6%) had complications, including hemophagocytic lymphohistiocytosis (19 cases, 11.0%), multiple organ failure (18 cases, 10.4%), lymphoma progression (18 cases, 10.4%), diffuse intravascular coagulation (4 cases, 2.3%), gastrointestinal bleeding/perforation (2 cases, 1.2%), myocarditis/arrhythmia (2 cases, 1.2%), and sepsis (1 case, 0.6%).
Forty-seven patients died from complications in this group, accounting for 27.2% (47/173) of all cases and for 72.3% of only those cases with complications (47/65). The cause of death involved one of the following complications: multiple organ failure (18 cases, 10.4%), hemophagocytic lymphohistiocytosis (14 cases, 8.1%), lymphoma progression (6 cases, 3.5%), diffuse intravascular coagulation (4 cases, 2.3%), gastrointestinal bleeding/perforation (2 cases, 1.2%), arrhythmia/myocarditis (2 cases, 1.2%), and severe infection (1 case, 0.6%).
Factors associated with mortality
Univariate analysis of factors related with EBV + T/NK-LPD-associated mortality are presented in Table 2. We observed that fever, lymphadenopathy, hepatosplenomegaly, EBER > 50/HPF, Ki-67 > 30%, and disease-associated complications demonstrated a statistically significant association with mortality (P < 0.05). There was no statistically significant difference between sex, age, WBC count, PLT count, and NK cell infection (P > 0.05) (Figure 5).
Table 2.
Univariate analysis of factors related with EBV + T/NK-LPD-associated mortality
| OR (95% Cl) | P value | |
|---|---|---|
| Sex | 1.18 (0.57-2.44) | NS |
| Age at onset | 1.04 (0.53-2.04) | NS |
| Fever | 4.79 (1.39-16.50) | 0.004 |
| Lymphadenopathy | 2.96 (1.22-7.16) | 0.013 |
| Hepatosplenomegaly | 3.17 (1.48-6.78) | 0.002 |
| Decreased WBC | 3.77 (0.89-15.85) | NS |
| Decreased PLT | 1.37 (0.43-4.36) | NS |
| NK cell infection | 0.991 (0.44-2.25) | NS |
| EBER > 50/HPF | 2.80 (1.21-6.51) | 0.014 |
| Ki-67 > 30% | 1.96 (0.87-4.45) | < 0.001 |
| Complications | 3.61 (2.44-5.35) | < 0.001 |
NS indicates not significant. P < 0.1 is shown; P < 0.05 (shown in bold) is statistically significant.
Figure 5.
Probability of survival rates from the time of disease onset. Overall survival rates from the time of disease onset were calculated between each subgroup (sex, onset age, presence or absence of complications, EBV-infected cell types, Ki-67 index, and EBER count) by the Kaplan-Meier estimation method.
Factors associated with complications
Univariate analysis (Table 3) demonstrated that fever, lymphadenopathy, hepatosplenomegaly, decreased WBC count, EBER > 50/HPF, and Ki-67 > 30% were correlated with complications of EBV infection (P < 0.05). Multivariate analysis showed that fever, hepatosplenomegaly, decreased WBC count, and Ki-67 > 30% were associated with the occurrence of complications, and thus, were statistically significant risk factors (P < 0.05).
Table 3.
Univariate and multivariate analyses of factors associated with complications in 173 patients with EBV + T/NK-LPD
| Univariate analysis | Multivariate analysis | |||
|---|---|---|---|---|
|
|
||||
| OR (95% Cl) | P value | OR (95% Cl) | P value | |
| Sex | 1.00 (0.52-1.94) | NS | ||
| Age | 1.70 (0.91-3.16) | 0.095 | 1.92 (0.97-3.80) | 0.060 |
| Fever | 4.41 (1.61-12.05) | 0.002 | 3.33 (1.13-9.81) | 0.029 |
| Lymphadenopathy | 3.24 (1.49-7.05) | 0.002 | 1.76 (0.74-4.15) | NS |
| Hepatosplenomegaly | 3.42 (1.74-6.75) | < 0.001 | 2.74 (1.32-5.71) | 0.007 |
| Decreased WBC | 3.73 (0.98-14.20) | 0.036 | 3.07 (1.09-10.39) | 0.049 |
| Decreased PLT | 1.95 (0.62-6.15) | NS | ||
| NK cell infection | 0.86 (0.41-1.87) | NS | ||
| EBER > 50/HPF | 2.81 (1.35-5.87) | 0.005 | 1.91 (0.86-4.22) | NS |
| Ki-67 > 30% | 2.67 (1.25-5.70) | 0.01 | 2.42 (1.09-5.37) | 0.030 |
NS indicates not significant. P < 0.1 is shown; P < 0.05 (shown in bold) is statistically significant.
Discussion
To the best of our knowledge, this is the first study investigating the prognostic factors of EBV + T/NK-LPD for patients in China. A few studies have described the clinical and laboratory features of EBV + T/NK-LPD and demonstrated that the disease has high mortality and high morbidity with life-threatening complications [12,14-16]. Compared with what is reported in the foreign literature, in China, it has been known that the prognostic factors of EBV infection, such as age at disease onset, WBC and PLT counts, NK cell infection, do not have any statistically significant correlation with mortality. However, other factors including fever, lymphadenopathy, hepatosplenomegaly, EBER > 50/HPF, Ki-67 > 30%, and disease-associated complications show a statistically significant correlation.
In the present study, we evaluated prognostic factors among patients with EBV + T/NK-LPDs. Multivariate analysis showed that fever, hepatosplenomegaly, decreased WBC count, and Ki-67 > 30% were independent risk factors for complications. Previously, two studies revealed that a later onset age (patients aged 8 years) was associated with mortality in patients with EBV + T/NK-LPD [14,17]. Furthermore, a report demonstrated that adult-onset chronic active Epstein-Barr virus infection (CAEBV) patients had more progressive and aggressive courses than childhood-onset cases [18]. However, the present study did not reveal such risk factors.
In previous research, patients with CD4+ T-cell infection had shorter survival rates than those with NK cell infection, whereas clinical categories were not correlated with survival rates [14]. Moreover, the onset age of patients with CD4+ T-cell infection was high (median, 14.5 years). These results suggest that adult patients with CD4 T-cell infection may have more aggressive features and are likely to develop multiple organ failure. Although the underlying reason is unclear, we should be cautious about rapid progression in patients with CD4+ T-cell infection. For patients in the present study, we did not have enough data to analyze whether they have CD4+ T-cell infection or not. This is an interesting aspect that will be addressed in a follow-up study.
The high mortality rate of EBV + T/NK-LPD was mainly due to serious and fatal complications, which has been demonstrated in previous reports and studies by other research groups [10,16]. In the present study, we determined the risk factors, and through a multivariate analysis, we show that fever, hepatic splenomegaly, low WBC count, and Ki-67 index are independent risk factors for complications associated with the aforementioned disease.
In the present study, there were 8 cases with other types of EBV + T/NK-LPD, including HV and HMB, one of which has been reported previously [19]. In addition, some of these cases developed systemic disease in a few months or years after diagnosis. Although some clinical symptoms did not appear serious, the auxiliary examination revealed a malignant tumor. On performing morphological analysis, we noted that there was no obvious damage of architecture. Therefore, we thought the localized EBV + T/NK-LPD represents a local or an organ-restricted lesion that can transform into a systemic disease after a certain time period. Regardless of transformation or chemotherapeutic intervention, localized EBV + T/NK-LPD could lead to serious life-threatening complications similar to systemic EBV + T/NK-LPD, which is consistent with previous case reports [20,21].
In the present study, we performed a preliminary statistical analysis on risk factors for complication occurrence and found some significant associations. Besides immunohistochemistry, we were unable to perform polymerase chain reaction for clonality of cell gene rearrangement and other molecular biology examinations using adequate samples, and this should be evaluated in future studies to find more potential risk factors. Furthermore, data on other related clinical aspects, such as liver function, bone marrow examination, blood smear analysis, detection of serum ferritin levels, and other post-treatment conditions remain limited. Thus, the determination and investigation of risk factors warrant the support of information on related clinical aspects of EBV + T/NK-LPD. Therefore, clinicians and pathologists should pay close attention to changes in the clinical information of patients as well as take precautionary measures against the occurrence of fatal complications.
Disclosure of conflict of interest
None.
References
- 1.Young LS, Rickinson AB. Epstein-Barr virus: 40 years on. Nat Rev Cancer. 2004;4:757–768. doi: 10.1038/nrc1452. [DOI] [PubMed] [Google Scholar]
- 2.Young LS, Yap LF, Murray PG. Epstein-Barr virus: more than 50 years old and still providing surprises. Nat Rev Cancer. 2016;16:789–802. doi: 10.1038/nrc.2016.92. [DOI] [PubMed] [Google Scholar]
- 3.Arai A, Yamaguchi T, Komatsu H, Imadome K, Kurata M, Nagata K, Miura O. Infectious mononucleosis accompanied by clonal proliferation of EBV-infected cells and infection of CD8-positive cells. Int J Hematol. 2014;99:671–675. doi: 10.1007/s12185-014-1548-4. [DOI] [PubMed] [Google Scholar]
- 4.Anagnostopoulos I, Hummel M, Kreschel C, Stein H. Morphology, immunophenotype, and distribution of latently and/or productively Epstein-Barr virus-infected cells in acute infectious mononucleosis: implications for the interindividual infection route of Epstein-Barr virus. Blood. 1995;85:744–750. [PubMed] [Google Scholar]
- 5.Klein G, Klein E, Kashuba E. Interaction of Epstein-Barr virus (EBV) with human B-lymphocytes. Biochem Biophys Res Commun. 2010;396:67–73. doi: 10.1016/j.bbrc.2010.02.146. [DOI] [PubMed] [Google Scholar]
- 6.Strickler JG, Fedeli F, Horwitz CA, Copenhaver CM, Frizzera G. Infectious mononucleosis in lymphoid tissue. Histopathology, in situ hybridization, and differential diagnosis. Arch Pathol Lab Med. 1993;117:269–278. [PubMed] [Google Scholar]
- 7.Cohen JI, Kimura H, Nakamura S, Ko YH, Jaffe ES. Epstein-Barr virus-associated lymphoproliferative disease in non-immunocompromised hosts: a status report and summary of an international meeting, 8-9 September 2008. Ann Oncol. 2009;20:1472–1482. doi: 10.1093/annonc/mdp064. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.Doeden K, Molina-Kirsch H, Perez E, Warnke R, Sundram U. Hydroa-like lymphoma with CD56 expression. J Cutan Pathol. 2008;35:488–494. doi: 10.1111/j.1600-0560.2007.00836.x. [DOI] [PubMed] [Google Scholar]
- 9.Suzuki K, Ohshima K, Karube K, Suzumiya J, Ohga S, Ishihara S, Tamura K, Kikuchi M. Clinicopathological states of Epstein-Barr virus-associated T/NK-cell lymphoproliferative disorders (severe chronic active EBV infection) of children and young adults. Int J Oncol. 2004;24:1165–1174. [PubMed] [Google Scholar]
- 10.Fujiwara S, Kimura H, Imadome K, Arai A, Kodama E, Morio T, Shimizu N, Wakiguchi H. Current research on chronic active Epstein-Barr virus infection in Japan. Pediatr Int. 2014;56:159–166. doi: 10.1111/ped.12314. [DOI] [PubMed] [Google Scholar]
- 11.Swerdlow SH, Campo E, Harris NL, Jaffe ES, Pileri SA, Stein H, Thiele J, Vardiman JW. WHO classification of tumours of haematopoietic and lymphoid tissues. Lyon: IARC; 2016. pp. 355–363. [Google Scholar]
- 12.Park S, Ko YH. Epstein-Barr virus-associated T/natural killer-cell lymphoproliferative disorders. J Dermatol. 2014;41:29–39. doi: 10.1111/1346-8138.12322. [DOI] [PubMed] [Google Scholar]
- 13.Ohshima K, Kimura H, Yoshino T, Kim CW, Ko YH, Lee SS, Peh SC, Chan JK CAEBV Study Group. Proposed categorization of pathological states of EBV-associated T/natural killer cell lymphoproliferative disorder (LPD) in children and young adults: overlap with chronic active EBV infection and infantile fulminant EBV T-LPD. Pathol Int. 2008;58:209–217. doi: 10.1111/j.1440-1827.2008.02213.x. [DOI] [PubMed] [Google Scholar]
- 14.Kimura H, Ito Y, Kawabe S, Gotoh K, Takahashi Y, Kojima S, Naoe T, Esaki S, Kikuta A, Sawada A, Kawa K, Ohshima K, Nakamura S. EBV-associated T/NK-cell lymphoproliferative diseases in nonimmunocompromised hosts: prospective analysis of 108 cases. Blood. 2012;119:673–686. doi: 10.1182/blood-2011-10-381921. [DOI] [PubMed] [Google Scholar]
- 15.Hong M, Ko YH, Yoo KH, Koo HH, Kim SJ, Kim WS, Park H. EBV-positive T/NK-cell lymphoproliferative disease of childhood. Korean J Pathol. 2013;47:137–147. doi: 10.4132/KoreanJPathol.2013.47.2.137. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.Ishihara S, Okada S, Wakiguchi H, Kurashige T, Morishima T, Kawa-Ha K. Chronic active Epstein-Barr virus infection in children in Japan. Acta Paediatrica. 1995;84:1271–1275. doi: 10.1111/j.1651-2227.1995.tb13547.x. [DOI] [PubMed] [Google Scholar]
- 17.Kimura H, Morishima T, Kanegane H, Ohga S, Hoshino Y, Maeda A, Imai S, Okano M, Morio T, Yokota S, Tsuchiya S, Yachie A, Imashuku S, Kawa K, Wakiguchi H Japanese Association for Research on Epstein-Barr Virus and Related Diseases. Prognostic factors for chronic active Epstein-Barr virus infection. J Infect Dis. 2003;187:527–533. doi: 10.1086/367988. [DOI] [PubMed] [Google Scholar]
- 18.Arai A, Imadome K, Watanabe Y, Yoshimori M, Koyama T, Kawaguchi T, Nakaseko C, Fujiwara S, Miura O. Clinical features of adult-onset chronic active Epstein-Barr virus infection: a retrospective analysis. Int J Hematol. 2011;93:602–609. doi: 10.1007/s12185-011-0831-x. [DOI] [PubMed] [Google Scholar]
- 19.Zhang YL, Xie JL, Zhang HC, Huang YH, Zhou XG. Solitary Epstein-Barr virus-positive cytotoxic T cell lymphoproliferative disease in stomach mimicking extranodal NK/T cell lymphoma. Int J Clin Exp Pathol. 2017;10:7116–7120. [Google Scholar]
- 20.Abdul-Ghafar J, Kim JW, Park KH, Cho MY. Fulminant Epstein-Barr virus-associated T-cell lymphoproliferative disorder in an immunocompetent middle-aged man presenting with chronic diarrhea and gastrointestinal bleeding. J Korean Med Sci. 2011;26:1103–1107. doi: 10.3346/jkms.2011.26.8.1103. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 21.Xiao HJ, Li J, Song HM, Li ZH, Dong M, Zhou XG. Epstein-Barr virus-positive T/NK-cell lymphoproliferative disorders manifested as gastrointestinal perforations and skin lesions: a case report. Medicine (Baltimore) 2016;95:e2676. doi: 10.1097/MD.0000000000002676. [DOI] [PMC free article] [PubMed] [Google Scholar]