Abstract
In this paper we want to demonstrate whether higher than normal levels of RDW, and lower than normal levels of MPV can be used as indicators of subclinical inflammation and tools for treatment decision in FMF or not. The participants in this study included 89 patients with FMF during attack-free periods and 30 healthy controls. The RDW and platelet counts were significantly higher, while the MPV was significantly lower in the patients with FMF group than healthy control group (P < 0.001; P = 0.005; P < 0.001, resp.). In the attack-free FMF group, a negative correlation was found between the MPV and RDW values (P < 0.001, r = −0.40). The positive correlation was found between the RDW and ESR (r = 0.23, P = 0.028). And the negative correlation was found between the MPV and CRP (r = −0.216, P = 0.042). Consequently, our results suggest that low MPV and high RDW levels may provide additional information about subclinical inflammation in FMF patients. But other strong predisposing factors affecting subclinical inflammation in FMF should be considered. Further studies with large numbers of patients are needed. Treatment of FMF should include not only prevention of acute attacks but also decreasing of the subclinical inflammation.
1. Introduction
Familial Mediterranean fever (FMF) is characterized by recurrent and self-limiting attacks with peritonitis, pleuritis, arthritis, and erysipelas-like erythema. It is inherited as an autosomal recessive trait and prominently presents among Sephardi Jews, Turks, Armenians, Arabs, and, to a much lesser extent, other ethnicities [1–3]. The attacks of FMF are only the tip of the iceberg, and inflammation maintains in attack-free remission periods in 30% of patients with FMF [4]. This maintaining subclinical inflammation induces endothelial dysfunction and increases the risk of developing significant complications such as atherothrombosis, anemia, splenomegaly, decreased bone mineral density, heart disease, and life-threatening secondary systemic amyloidosis [5, 6]. Subclinical inflammation is shown by high levels of acute-phase proteins, cytokines, and inflammation-induced proteins (e.g., overproduction of C-reactive protein (CRP) or serum amyloid-A (SAA) and persistently elevated fibrinogen levels and erythrocyte sedimentation rates (ESR)) in attack-free FMF periods [5, 7–9].
Red cell distribution width (RDW) is commonly accepted as part of the hemogram and refers to the changeability in the size of the erythrocytes in the peripheral circulation. RDW is used to refer to the differential diagnosis of anemia, and it increases during inflammation; therefore, RDW can increase as a result of chronic inflammation [10, 11].
Platelet volume, a marker of platelet function and activation, is generally measured as the mean platelet volume (MPV) [12]. Low MPV levels can be present in high-grade inflammatory diseases such as active RA and AS or attacks of FMF. This has been demonstrated in previous studies [13–16]. An increased MPV was found to be negatively correlated with inflammation in patients with ulcerative colitis and Crohn's disease [17], and, in a recent study, it was shown that anti-TNF-alpha therapy decreases the MPV in AS patients [18].
In this paper we want to demonstrate whether higher than normal levels of RDW and lower than normal levels of MPV can be used as indicators of subclinical inflammation and tools for treatment decision in FMF or not.
2. Materials and Methods
In this study, 89 patients with FMF (male/female: 30/59, mean age: 31.03 ± 10.2/32.18 ± 10) and 30 age- and sex-matched healthy controls (male/female: 10/20, mean age: 32.9 ± 6.5/30.65 ± 5.2) were enrolled. The patient group was comprised of 89 patients who fulfilled clinical diagnostic criteria for FMF. All patients were under colchicine treatment and they were in an attack-free period. All of them were responders to colchicine with ≤1 FMF attack within the six months or without any attacks over the twelve months. The ESR, CRP, white blood cell count, platelet count, hemoglobin, MPV, and RDW levels were retrospectively recorded. These patients were evaluated in accordance with the “Disease Severity Score,” the Tel-Hashomer severity scoring, which includes six elements: disease onset age, dose of colchicine, number of involved sites in one attack and during the course of the disease, and the presence of pleuritic and erysipelas-like erythema.
3. Statistical Analysis
Student's t-test and one-way ANOVA were used for comparison of averages. Pearson's correlation analyses were performed to evaluate other factors. P value of <0.05 was accepted as statistically significant.
4. Results
The demographic features and laboratory results of attack-free patients with FMF and the control healthy groups are shown in Table 1. Mean age of disease onset was 19.4 ± 9.66 (min: 1 and max: 44) years. Median colchicine dose was 1.50 (min: 1 and max ≥ 1.5) mg/day. The mean age, male/female ratio, mean levels of hemoglobin, and white blood cell count were similar in the two groups. Two of 89 (2.24%) patients with FMF had amyloidosis in our study. The RDW and platelet counts were significantly higher and the MPV was significantly lower in the patients with FMF group (15.59 ± 1.6% versus 12.9 ± 0.8%, P < 0.001; 289 ± 78.2 K/μL versus 245.63 ± 55.7 K/μL, P = 0.005; and 7.9 ± 1 fL versus 9.4 ± 0.9 fL, P < 0.001, resp.). All parameters excluding hemoglobin were similar for males and females. Hemoglobin counts were significantly higher in male group (13.01 ± 1.06 versus 14.75 ± 1.18, P = 0.00) (Table 2). However hemoglobin counts were in normal range in both of the two groups. In the attack-free FMF group, a negative correlation was found between the MPV and RDW values (P < 0.001, r = −0.40). Median disease severity score was 4.6 (min: 2 and max: 13), where 69 cases (77.5%) were scored as “mild,” 16 cases (17.9%) were “moderate,” and 4 cases (4.49%) were “severe.” The correlation was not found between the disease severity score and MPV, RDW, ESR, and CRP values (P = 0.82, r = −0.024; P = 0.75, r = −0.033; P = 0.24, r = 0.12; and P = 0.57, r = −0.061, resp.). However, the positive correlation was found between the RDW and ESR (r = 0.23, P = 0.028). And the negative correlation was found between the MPV and CRP (r = −0.216, P = 0.042).
Table 1.
Group of attack-free patients with FMF (n = 89) Mean ± SD |
Healthy control group (n = 30) Mean ± SD |
P value | |
---|---|---|---|
Age (years) | 31.8 ± 10 | 31.4 ± 5.7 | 0.83 |
Gender (M/F) | 30/59 | 10/20 | 1 |
Hemoglobin (g/dL) | 13.4 ± 1.38 | 14.02 ± 1.26 | 0.05 |
MPV (fL) | 7.9 ± 1 | 9.4 ± 0.9 | <0.001 |
RDW (%) | 15.59 ± 1.6 | 12.9 ± 0.8 | <0.001 |
Platelet count (103/mm3) | 289 ± 78.2 | 245.63 ± 55.7 | 0.005 |
White blood cell (/mm3) | 7116.2 ± 1737 | 7183 ± 2075 | 0.86 |
ESR: erythrocyte sedimentation rate; F: female; M: male; MPV: mean platelet volume; RDW: red cell distribution width; SD: standard deviation.
Table 2.
Gender | N | Mean | Std. deviation | P value | |
---|---|---|---|---|---|
Age | F M |
70 40 |
31.79 31.50 |
9.06 9.39 |
0.86 |
| |||||
WBC | F M |
79 40 |
7081.27 7232.98 |
1682.840 2072.126 |
0.67 |
| |||||
Plt | F M |
79 40 |
284.00 267.78 |
72.179 81.585 |
0.27 |
| |||||
RDW | F M |
79 40 |
15.0671 14.5620 |
1.94176 1.43472 |
0.14 |
| |||||
MPV | F M |
79 40 |
8.4051 8.1080 |
1.28828 1.11365 |
0.21 |
| |||||
Hbg | F M |
79 40 |
13.0139 14.7568 |
1.06334 1.18326 |
0.00 |
F: female; M: male; MPV: mean platelet volume (fL); RDW: red cell distribution width (%); WBC: white blood cell (/mm3); Plt: platelet count (103/mm3); Hbg: hemoglobin (g/dL).
5. Discussion
In our study we found the positive correlation between the RDW and ESR and the negative correlation between the MPV and CRP in attack-free FMF period. Förhécz et al. showed that CRP had a significantly positive correlation with RDW. It was found that, between prealbumin, which is the negative acute-phase reactant, and RDW, a significantly negative correlation exists in patients with heart failure [11]. In a recent study, Lippi et al. showed a correlation of RDW with CRP and ESR in unselected adult outpatients [19], while Erdem et al. demonstrated that patients with an inflammatory condition, such as reactive systemic AA amyloidosis, have higher RDWs and lower MPVs [20].
In our study the RDW and platelet counts were significantly higher and the MPV was significantly lower in the patients with attack-free FMF group than healthy control group. Subclinical inflammation is observed during the course of FMF and diagnosed by measuring cytokine levels including interleukin (IL)-6, IL-8, IL-12, IL-17, IL-18, interferon, and tumor necrosis factor, which have been shown to increase during and between the attacks [21–28]. IL-6 is one of the proinflammatory cytokines that can cause thrombocytosis and change platelet volume. It has been shown to increase the platelet number and decrease the MPV in patients with cancer [29]. So the higher RDW and lower MPV can be observed in chronic inflammation such as attack-free FMF patients.
In our study we did not find correlation between the “Disease Severity Score” and MPV, RDW, ESR, and CRP values. This can be explained with other factors that can affect severity of attacks and ongoing subclinical inflammation in FMF. Patients with phenotype II FMF without ever having an acute, painful, febrile attack develop secondary amyloidosis because of subclinical inflammation. A maintained, long-term elevation in SAA levels is prerequisite for occurring of secondary amyloidosis [30, 31]. Levels of both CRP and SAA are increased in 30–90% of patients with FMF during attack-free period, even while using colchicine therapy. Levels of these proteins are also increased in asymptomatic carriers of MEFV mutations which means that these apparently unaffected individuals have ongoing subclinical inflammation [5, 32].
On the other hand colchicine therapy affects strongly subclinical inflammation in FMF. Other factors such as male sex, age of disease onset, frequency of acute attacks, joint involvement during attacks, risk factors for the development of amyloidosis, and markers of inflammation are related to chronic inflammation in FMF [33–35]. As a result of our study increasing of RDW and decreasing of MPV levels not only can occur with severe chronic inflammation and could be useful to predict who will develop amyloidosis but also other strong predisposing factors should be considered.
The acute attacks of FMF are self-limited. Treatment is purposed of reprieve reducing pain with analgesics, NSAIDs, and rest during attacks. Colchicine does not suppress acute attack. The aim of colchicine therapy is to prevent acute attacks and amyloidosis [36–38]. Colchicine therapy is started as an oral dose of 1.0–1.2 mg daily and increased as needed to control attacks until a maximum dose of 2.0–2.4 mg daily is reached [6]. Colchicine therapy reduces levels of the markers of subclinical inflammation such as ESR, CRP, and white blood cell count in asymptomatic patients with FMF. These markers can be used for following colchicine response [39]. SAA level decreases with increased colchicine dose in attack-free patients with FMF [40]. Our study supports that RDW and MPV can be used like these markers. If patient's adherence is bad or response to treatment is poor despite sufficient dose, colchicine dose should be raised to 2.5–3.0 mg daily or add a weekly dose (1 mg) of intravenous colchicine or even try treatment with subcutaneous interferon-alpha [41].
6. Conclusions
Consequently, our results suggest that low MPV and high RDW levels may provide additional information about persistent subclinical inflammation in FMF patients during attack-free periods. But other strong predisposing factors affecting subclinical inflammation in FMF should be considered. Further studies with large numbers of patients are needed.Treatment of FMF should include not only prevention of acute attacks but also decreasing of the chronic subclinical inflammation.
Conflict of Interests
The authors declare that there is no conflict of interests regarding the publication of this paper.
References
- 1.Drenth J. P. H., van der Meer J. W. M. Hereditary periodic fever. The New England Journal of Medicine. 2001;345(24):1748–1757. doi: 10.1056/NEJMra010200. [DOI] [PubMed] [Google Scholar]
- 2.Onen F. Familial Mediterranean fever. Rheumatology International. 2006;26(6):489–496. doi: 10.1007/s00296-005-0074-3. [DOI] [PubMed] [Google Scholar]
- 3.Fonnesu C., Cerquaglia C., Giovinale M., et al. Familial Mediterranean fever: a review for clinical management. Joint Bone Spine. 2009;76(3):227–233. doi: 10.1016/j.jbspin.2008.08.004. [DOI] [PubMed] [Google Scholar]
- 4.Livneh A., Langevitz P., Zemer D., et al. The changing face of familial Mediterranean fever. Seminars in Arthritis and Rheumatism. 1996;26(3):612–627. doi: 10.1016/S0049-0172(96)80012-6. [DOI] [PubMed] [Google Scholar]
- 5.Lachmann H. J., Şengül B., Yavuzşen T. U., et al. Clinical and subclinical inflammation in patients with familial Mediterranean fever and in heterozygous carriers of MEFV mutations. Rheumatology. 2006;45(6):746–750. doi: 10.1093/rheumatology/kei279. [DOI] [PubMed] [Google Scholar]
- 6.Ben-Zvi I., Livneh A. Chronic inflammation in FMF: markers, risk factors, outcomes and therapy. Nature Reviews Rheumatology. 2011;7(2):105–112. doi: 10.1038/nrrheum.2010.181. [DOI] [PubMed] [Google Scholar]
- 7.Korkmaz C., Ozdogan H., Kasapçopur O., Yazici H. Acute phase response in familial Mediterranean fever. Annals of the Rheumatic Diseases. 2002;61(1):79–81. doi: 10.1136/ard.61.1.79. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.Thurmon T. F. Genetics, aging, and the heart. The Journal of the Louisiana State Medical Society. 1998;150(8):356–366. [PubMed] [Google Scholar]
- 9.Frensdorff A., Sohar E., Heller H. Plasma fibrinogen in familial Mediterranean fever. Annals of Internal Medicine. 1961;55:448–455. doi: 10.7326/0003-4819-55-3-448. [DOI] [PubMed] [Google Scholar]
- 10.Yesil A., Senates E., Bayoglu I. V., Erdem E. D., Demirtunc R., Kurdas Ovunc A. O. Red cell distribution width: a novel marker of activity in inflammatory bowel disease. Gut and Liver. 2011;5(4):460–467. doi: 10.5009/gnl.2011.5.4.460. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11.Förhécz Z., Gombos T., Borgulya G., Pozsonyi Z., Prohászka Z., Jánoskuti L. Red cell distribution width in heart failure: prediction of clinical events and relationship with markers of ineffective erythropoiesis, inflammation, renal function, and nutritional state. American Heart Journal. 2009;158(4):659–666. doi: 10.1016/j.ahj.2009.07.024. [DOI] [PubMed] [Google Scholar]
- 12.Bath P. M. W., Butterworth R. J. Platelet size: measurement, physiology and vascular disease. Blood Coagulation and Fibrinolysis. 1996;7(2):157–161. [PubMed] [Google Scholar]
- 13.Gasparyan A. Y., Ayvazyan L., Mikhailidis D. P., Kitas G. D. Mean platelet volume: a link between thrombosis and inflammation? Current Pharmaceutical Design. 2011;17(1):47–58. doi: 10.2174/138161211795049804. [DOI] [PubMed] [Google Scholar]
- 14.Milovanovic M., Nilsson E., Järemo P. Relationships between platelets and inflammatory markers in rheumatoid arthritis. Clinica Chimica Acta. 2004;343(1-2):237–240. doi: 10.1016/j.cccn.2003.12.030. [DOI] [PubMed] [Google Scholar]
- 15.Baynes R. D., Lamparelli R. D. V., Bezwoda W. R., Gear A. J., Chetty N., Atkinson P. Platelet parameters—part II: platelet volume-number relationships in various normal and disease states. South African Medical Journal. 1988;73(1):39–43. [PubMed] [Google Scholar]
- 16.Kisacik B., Tufan A., Kalyoncu U., et al. Mean platelet volume (MPV) as an inflammatory marker in ankylosing spondylitis and rheumatoid arthritis. Joint Bone Spine. 2008;75(3):291–294. doi: 10.1016/j.jbspin.2007.06.016. [DOI] [PubMed] [Google Scholar]
- 17.Kapsoritakis A. N., Koukourakis M. I., Sfiridaki A., et al. Mean platelet volume: a useful marker of inflammatory bowel disease activity. American Journal of Gastroenterology. 2001;96(3):776–781. doi: 10.1016/S0002-9270(00)02414-X. [DOI] [PubMed] [Google Scholar]
- 18.Yazici S., Yazici M., Erer B., et al. The platelet functions in patients with ankylosing spondylitis: anti-TNF-α therapy decreases the mean platelet volume and platelet mass. Platelets. 2010;21(2):126–131. doi: 10.3109/09537100903470306. [DOI] [PubMed] [Google Scholar]
- 19.Lippi G., Targher G., Montagnana M., Salvagno G. L., Zoppini G., Guidi G. C. Relation between red blood cell distribution width and inflammatory biomarkers in a large cohort of unselected outpatients. Archives of Pathology & Laboratory Medicine. 2009;133(4):628–632. doi: 10.5858/133.4.628. [DOI] [PubMed] [Google Scholar]
- 20.Erdem E., Erdem D., Dilek M., et al. Red cell distribution width and mean platelet volume in amyloidosis. Clinical and Applied Thrombosis/Hemostasis. 2012 doi: 10.1177/1076029612462761. [DOI] [PubMed] [Google Scholar]
- 21.Gang N., Drenth J. P. H., Langevitz P., et al. Activation of the cytokine network in familial Mediterranean fever. Journal of Rheumatology. 1999;26(4):890–897. [PubMed] [Google Scholar]
- 22.Kiraz S., Ertenli I., Arici M., et al. Effects of colchicine on inflammatory cytokines and selectins in familial Mediterranean fever. Clinical and Experimental Rheumatology. 1998;16(6):721–724. [PubMed] [Google Scholar]
- 23.Haznedaroglu S., Öztürk M. A., Sancak B., et al. Serum interleukin 17 and interleukin 18 levels in familial Mediterranean fever. Clinical and Experimental Rheumatology. 2005;23(4):S77–S80. [PubMed] [Google Scholar]
- 24.Simsek I., Pay S., Pekel A., et al. Serum proinflammatory cytokines directing T helper 1 polarization in patients with familial Mediterranean fever. Rheumatology International. 2007;27(9):807–811. doi: 10.1007/s00296-006-0301-6. [DOI] [PubMed] [Google Scholar]
- 25.Erken E., Ozer H. T. E., Gunesacar R. Plasma interleukin-10 and interleukin-12 levels in patients with familial Mediterranean fever. Rheumatology International. 2006;26(9):862–864. doi: 10.1007/s00296-005-0099-7. [DOI] [PubMed] [Google Scholar]
- 26.Manukyan G. P., Ghazaryan K. A., Ktsoyan Z. A., et al. Cytokine profile of Armenian patients with familial Mediterranean fever. Clinical Biochemistry. 2008;41(10-11):920–922. doi: 10.1016/j.clinbiochem.2008.03.017. [DOI] [PubMed] [Google Scholar]
- 27.Notarnicola C., Didelot M. N., Seguret F., Demaille J., Touitou I. Enhanced cytokine mRNA levels in attack-free patients with familial Mediterranean fever. Genes and Immunity. 2002;3(1):43–45. doi: 10.1038/sj.gene.6363813. [DOI] [PubMed] [Google Scholar]
- 28.Köklü S., Öztürk M. A., Balci M., Yüksel O., Ertenli I., Kiraz S. Interferon-gamma levels in familial Mediterranean fever. Joint Bone Spine. 2005;72(1):38–40. doi: 10.1016/j.jbspin.2004.03.011. [DOI] [PubMed] [Google Scholar]
- 29.Clarke D., Johnson P. W. M., Banks R. E., et al. Effects of interleukin 6 administration on platelets and haemopoietic progenitor cells in peripheral blood. Cytokine. 1996;8(9):717–723. doi: 10.1006/cyto.1996.0095. [DOI] [PubMed] [Google Scholar]
- 30.Balci B., Tinaztepe K., Yilmaz E., et al. MEFV gene mutations in familial Mediterranean fever phenotype II patients with renal amyloidosis in childhood: a retrospective clinicopathological and molecular study. Nephrology Dialysis Transplantation. 2002;17(11):1921–1923. doi: 10.1093/ndt/17.11.1921. [DOI] [PubMed] [Google Scholar]
- 31.Livneh A. Amyloidosis of Familial Mediterranean Fever (FMF)—insights to FMF phenotype II. Harefuah. 2006;145(10):743–782. [PubMed] [Google Scholar]
- 32.Tunca M., Kirkali G., de Soytürk M., Akar S., Pepys M. B., Hawkins P. N. Acute phase response and evolution of familial Mediterranean fever. The Lancet. 1999;353(9162):p. 1415. doi: 10.1016/S0140-6736(99)00990-3. [DOI] [PubMed] [Google Scholar]
- 33.Mor A., Shinar Y., Zaks N., et al. Evaluation of disease severity in familial Mediterranean fever. Seminars in Arthritis and Rheumatism. 2005;35(1):57–64. doi: 10.1016/j.semarthrit.2005.02.002. [DOI] [PubMed] [Google Scholar]
- 34.Gershoni-Baruch R., Brik R., Lidar M., Shinawi M., Livneh A. Male sex coupled with articular manifestations cause a 4-fold increase in susceptibility to amyloidosis in patients with familial Mediterranean fever homozygous for the M694V-MEFV mutation. Journal of Rheumatology. 2003;30(2):308–312. [PubMed] [Google Scholar]
- 35.Padeh S., Shinar Y., Pras E., et al. Clinical and diagnostic value of genetic testing in 216 Israeli children with familial Mediterranean fever. Journal of Rheumatology. 2003;30(1):185–190. [PubMed] [Google Scholar]
- 36.Dinarello C. A., Wolff S. M., Goldfinger S. E., Dale D. C., Alling D. W. Colchicine therapy for familial Mediterranean fever. A double blind trial. The New England Journal of Medicine. 1974;291(18):934–937. doi: 10.1056/NEJM197410312911804. [DOI] [PubMed] [Google Scholar]
- 37.Goldfinger S. E. Colchicine for familial Mediterranean fever. The New England Journal of Medicine. 1972;287(25):p. 1302. doi: 10.1056/NEJM197212212872514. [DOI] [PubMed] [Google Scholar]
- 38.Zemer D., Revach M., Pras M., et al. A controlled trial of colchicine in preventing attacks of familial Mediterranean fever. The New England Journal of Medicine. 1974;291(18):932–934. doi: 10.1056/NEJM197410312911803. [DOI] [PubMed] [Google Scholar]
- 39.Ozçakar Z. B., Yalçinkaya F., Yüksel S., Acar B., Gökmen D., Ekim M. Possible effect of subclinical inflammation on daily life in familial Mediterranean fever. Clinical Rheumatology. 2006;25(2):149–152. doi: 10.1007/s10067-005-1148-z. [DOI] [PubMed] [Google Scholar]
- 40.Duzova A., Bakkaloglu A., Besbas N., et al. Role of A-SAA in monitoring subclinical inflammation and in colchicine dosage in familial Mediterranean fever. Clinical and Experimental Rheumatology. 2003;21(4):509–514. [PubMed] [Google Scholar]
- 41.Tweezer-Zaks N., Rabinovich E., Lidar M., Livneh A. Interferon-α as a treatment modality for colchicine-resistant familial Mediterranean fever. Journal of Rheumatology. 2008;35(7):1362–1365. [PubMed] [Google Scholar]