Red Cell Distribution Width (RDW) as a Marker of Subclinical Inflammation in Children with Familial Mediterranean Fever.

BACKGROUND

Familial Mediterranean fever (FMF) is an autoinflammatory disease with potentially devastating effects on the kidney, and the chronic subclinical inflammation may also be deleterious. Further, proteinuria has been associated with chronic inflammatory states.

OBJECTIVE

We aimed to probe whether red cell distribution width (RDW) can be used as a reliable indicator of subclinical disease in FMF patients.

METHODS

Ninety-nine children with FMF, according to the new pediatric FMF criteria, were included in the present study. All were attack-free at the time of the study. They were compared with 44 healthy age-matched controls. For all patients and controls, the following tests were done: Complete blood count (in the form of red cell count, leukocyte count, platelet count, hemoglobin, RDW and MCV), CRP, ESR, creatinine and an estimated glomerular filtration rate (e-GFR). For patients, serum and urine albumin and albumin/creatinine ratio were also determined. Group 1 consisted of 61 patients, who were not suffering from microalbuminuria, and Group 2 consisted of 38 patients who had confirmed albuminuria.

RESULTS

RDW and ESR were significantly higher in patients with FMF without microalbuminuria than in controls, while MCV was smaller in controls (p<0.05).

CONCLUSION

RDW can be used as an indicator of subclinical inflammation in children with FMF. The tests are easy to perform and cheaper than more sophisticated tests. Microalbuminuria may be silent and occur on the background of normal levels of acute-phase reactants. All cases must be routinely checked for microalbuminuria.