Mean platelet volume in familial Mediterranean fever related AA amyloidosis and comparison with common primary glomerular diseases

Background/aim: Compared to healthy controls, mean platelet volume (MPV) is frequently higher in patients with Familial Mediterranean fever (FMF) but lower in AA amyloidosis patients. The reason for the difference in MPV levels in FMF patients with and without AA amyloidosis is unclear. The aim of the study was to determine whether low MPV is unique to AA amyloidosis or MPV is similarly low in all glomerular diseases as a result of proteinuria and/or renal dysfunction. Materials and methods: We compared pre-biopsy MPV levels of patients with AA amyloidosis secondary to FMF, to MPV levels of patients with membranous glomerulonephritis, focal segmental glomerulosclerosis (FSGS) and IgA nephropathy that all present with proteinuria and renal dysfunction. Results: 703 patients (411 male, 292 female) were included in the study. Mean age was 42.6  14.3 years. There were 124 patients with AA amyloidosis, 224 patients with IgA nephropathy, 188 patients with membranous glomerulonephritis, and 167 patients wit h FSGS. Patients with AA amyloidosis had lower MPV levels compared to patients without AA amyloidosis (7.9  1.2 fL vs. 8.2  0.9 fL respectively, p = 0.008). Patients with AA amyloidosis had significantly lower MPV compared to patients with each of the othe r diagnoses. Independent predictors of MPV were platelet count (ß = ­0.321, p < 0.001) and CRP (ß = ­ 0.134, p < 0.03). Conclusion: This study is the largest study of MPV in patients with biopsy proven AA amyloidosis and confirms previous studies reporting low MPV in AA amyloidosis. This study indicates that low MPV in AA amyloidosis cannot be explained with proteinuria and renal dysfunction.

The clinical features and outcomes of Turkish patients with IgG4-related disease:a single-center experience

Background/aim: Since the majority of the IgG4-related disease (IgG4-RD) patients in the literature are from the Far East and the United States, there is a lack of large series from other parts of the world. We aimed to identify the clinical characteristics and outcome of Turkish IgG4-RD patients from a tertiary center. Materials and methods: Fifty-two patients classified as having definite IgG4-RD according to comprehensive diagnostic criteria were included in the study. Patients not fulfilling the definite criteria due to lack of pathologic specimen and/or serum IgG4 levels were excluded (n = 47). Clinical, laboratory, and histopathological features and treatment approaches were analyzed. Results: Median age at diagnosis was 51.1 years and sex predominance was not observed (male/female: 26/26). Median follow-up duration was 18 (IQR 25­75: 8­35) months. Retroperitoneal fibrosis was the most frequent presentation. Twenty-four (46.1%) patients had localized involvement. Corticosteroids were the mainstay of treatment (92.5%). Rituximab had been used for cases resistant to previous treatment or with relapses in 19 (47.5%) patients. A complete response was achieved in 52.5% and partial response (<50% regression) in 40%. Conclusion: This large and first cohort of IgG4-RD patients from Turkey showed similar clinical features to European cohorts, except for the male predominance in previous cohorts. Corticosteroids and rituximab are effective in IgG4-RD but there is still uncertainty about the usage of corticosteroid-sparing agents.