Importance of hematological markers in familial Mediterranean fever in terms of disease severity and amyloidosis

Abstract

There are limited follow-up parameters for familial Mediterranean fever (FMF) related to disease severity and amyloidosis. Some hematological markers are emerging to assess inflammation. In this study, we hypothesized that some hematological parameters could be used to determine disease severity and amyloidosis in FMF. We included 274 adult FMF patients, and evaluated the relationship between neutrophil lymphocyte ratio (NLR), monocyte-lymphocyte ratio (MLR) and platelet-lymphocyte ratio (PLR), platelet counts and leukocyte counts, mean erythrocyte haemoglobin concentration (MCHC) and mean erythrocyte haemoglobin (MCH) with disease severity and amyloidosis. First, we classified patients according to disease severity and presence of amyloidosis. We then compared the parameters within the groups. In addition, we determined predictive cut-off values with ROC analysis. Finally, we correlated the change in ISSF scores with the change in hematological parameters of 52 patients with follow-up hematological indices after six months. The patients with severe-moderate group had higher CRP levels (p < 0.001), white blood cell (p = 0.002) and neutrophil counts (p = 0.004) and, conversely, lower MCHC levels (p = 0.001) than patients with mild disease severity. FMF patients with amyloidosis had higher neutrophil (p = 0.04) and monocyte count (p = 0.02), increased NLR (p = 0.01) and lower MLR (p = 0.02) levels than those without. In addition, MCHC levels were also lower in the severe-moderate group in the follow-up analyses after sixth months (p = 0.03). MCHC, neutrophil and monocyte counts, NLR, MLR may be associated with poor prognosis in FMF patients. These parameters can be used in conjunction with acute phase reactant and clinical features to assess disease status.

Keywords: Erythrocyte indices; Familial Mediterranean fever; Monocyte; Neutrophils.