Can RDW be used as a screening test for subclinical inflammation in children with FMF? Is RDW related to MEFV gene mutations?

OBJECTIVE: Subclinical inflammation, an insidious feature of familial Mediterranean fever (FMF), can lead to life-threatening amyloidosis. We aimed to investigate acute phase reactants and complete blood count parameters to identify a useful marker for subclinical inflammation in children with FMF. A secondary aim was to identify an association between subclinical inflammation and specific Mediterranean fever (MEFV) gene mutations. METHODS: This study included 420 pediatric patients with FMF. Laboratory parameters of patients during the attack-free period and MEFV gene mutation analyses were recorded. RESULTS: Of the 420 patients, 88 (21%) had subclinical inflammation. Of those with subclinical inflammation, 48 (55%) had mutations in exon 10, 36 (41%) had M694V mutation, and 10 (11%) had M694V homozygous mutation. Red cell distribution width (RDW) value was higher in exon 10, M694V, and M694V homozygous mutations compared to other mutations. RDW was positively correlated with serum amyloid A (SAA) (r = 0.390, p = 0.0001). Analysis of a receiver-operating characteristic curve of RDW revealed that its optimal cut-off value for subclinical inflammation was 12.69%, its sensitivity was 64.10%, and its specificity was 50.90%. The area under the curve was 0.616 (p = 0.004, 95% confidence interval = 0.538-0.695). CONCLUSION: We suggest that RDW can be used as a screening test as a marker of subclinical inflammation. A high RDW value should alert the clinician about subclinical inflammation in FMF children's patients with M694V (heterozygous, homozygous, compound heterozygous) mutation. Key Points • Subclinical inflammation in FMF patients can lead to amyloidosis. • RDW can be a predictor of subclinical inflammation. • RDW can be used as a screening test for subclinical inflammation in FMF patients with M694V mutation.

Association between panel reactive antibody and antiendothelial cell antibody positivity in kidney transplant patients.

OBJECTIVES: Endothelium is the major tissue for hyperacute and acute rejection. Binding of antibody to endothelium activates several immunologic mechanisms. Antiendothelial cell antibodies are a group of nonhuman leukocyte antigen antibodies that may play a role in the induction of an immunologic reaction that triggers inflammation. The aim of this study was to investigate whether there was an association between antiendothelial cell antibody positivity and panel reactive antibody positivity in renal transplant patients. MATERIALS AND METHODS: In this study, we investigated the association between antiendothelial cell antibodies and panel reactive antibody Class I class II crossmatch positivity in patients, and compared these results with results from 100 healthy volunteers. All serum samples were analyzed by bead-based technology for calculated panel reactive antibody positivity; in addition, slides were used, each containing human umbilical vein endothelial cells and capillary-rich tissue for antiendothelial cell antibody positivity. RESULTS: Antiendothelial cell antibodies was positive in 48 of 89 patients (panel reactive antibody Class I class II negative), 22 of 35 patients (class I-positive), 25 of 39 patients (class II-positive), 26 of 40 (class I class II positive), and 37 of 57 serologic and flow cytometry crossmatch-positive patients (P ≤ .016), and ultimately, in 122 of 205 patients and 25 of 100 volunteers (P ≤ .001). Antiendothelial cell antibody positivity was more frequent in panel reactive antibody-positive than negative patients and the control group. CONCLUSIONS: Binding of antiendothelial cell antibodies to endothelial cells may activate complement by the classical pathway and cause upregulation of adhesion molecules. This study questioned the antigenic specificity of antiendothelial cell antibodies. Our study results showed that antiendothelial cell antibodies may play an important role for graft destruction, independent of panel reactive antibody and crossmatch positivity.