Background Neuro-Behçet's Syndrome (NBS) is a rare manifestation of Behçet's Syndrome (BS) with significant morbidity and mortality. Vitamin B12 (VitB12) deficiency is associated with neurologic manifestations. Elevation in the serum concentrations of both homocysteine (Hcy) and methylmalonic acid (MMA) appears to be more sensitive than low serum VitB12 alone for the diagnosis of VitB12 deficiency. Hcy is known to be toxic for endothelial cells and hyperhomocysteinemia was reported to be an independent risk factor for venous thrombosis in BS.
Objectives To investigate the role of serum levels of VitB12, Hcy and MMA in development of NBS and to compare them with healthy controls.
Methods Serum VitB12, Hcy and MMA were measured using ELISA in fifty six patients fulfilling the criteria of the International Study Group for Behçet's Disease and thirty matched healthy controls. Patients using colchicine were also excluded. Study participants were grouped as BS patients with NBS, BS patients without NBS, and healthy controls. Normal blood ranges were accepted as 187-911 pg/ml for VitB12, 5-14 μmol/L for Hcy, and 3.1-15.3 ng/mL for MMA.
Results Median serum levels of VitB12, Hcy and MMA are shown in Table 1. There was no significant difference between the groups regarding serum VitB12 and Hcy levels. Serum MMA levels were normal in patients with BS. However, serum MMA levels were significantly higher in healthy controls than patients with BS with or without NBS (p≤0.05).
Conclusions Unlike previously reported association in venous thrombosis, we did not find any association between VitB12 deficiency and neurological involvement in patients with BS. Further studies are needed to investigate the underlying mechanisms of the variable effects of VitB12 deficiency on different clinical manifestations of BS.
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Disclosure of Interest None declared