unusual association between familial mediterranean fever and IgM nephropathy

ABSTRACT

To report a case with the diagnosis of IgM nephropathy and familial Mediterranean fever [FMF]. Clinical Presentation and Intervention A 9-year-old boy was admitted to our hospital with recurrent abdominal pain since the age of 4 years. Laboratory investigations revealed a sedimentation rate of 88 mm/h, C-reactive protein 83.2 mg/l [0-10 mg/l], white blood cell count 12,700/mm3, fibrinogen 622 mg/dl [200-400 mg/dl] and serum amyloid A 186 mg/l [0-5.8 mg/l]. Urinalysis revealed +2 proteinuria. A 24-hour urinary protein excretion was 12 mg/m2/h. M694V homozygous mutation was identified in exon 10. Percutaneous renal biopsy showed mesangial cell proliferation and increased mesangial matrix in the glomeruli, without amyloid accumulation. Immunofluorescence study showed IgM [+1] and C1q [+1] deposits. Treatment with 1 mg/day colchicine was started. Six weeks later, proteinuria had disappeared and the patient was asymptomatic. This case illustrates the unusual association of FMF with non-amyloid glomerulopathy. Glomerular diseases such as IgM nephropathy may be seen as a manifestation of FMF