冷球蛋白是在低于37°C的温度下沉淀并在再加热时溶解的免疫球蛋白。它们可以诱发肾脏受累的小血管血管炎。冷球蛋白血症性肾小球肾炎是一种罕见的表现,发生在单克隆丙种球蛋白病患者中。特别是Waldenström的巨球蛋白血症。我们介绍了一个52岁的患者,有皮肤血管炎和甲状腺功能减退症的病史,出现全身性水肿的人,中度贫血,高胆固醇血症,肾病范围蛋白尿12.69克/天,微血尿,动脉高血压,通过经典途径和低补体血症,无急性肾损伤,血清学研究阴性,冷球蛋白阳性。血清和尿蛋白电泳和免疫固定研究显示IgM和κ轻链的单克隆带。肾活检符合冷球蛋白血症性肾小球肾炎。在异常蛋白血症和冷球蛋白血症性肾小球肾炎的情况下,进行骨髓穿刺和活检,导致Waldenström巨球蛋白血症的诊断。已描述了与I型冷球蛋白血症相关的单克隆丙种球蛋白病。这种描述的关联并不常见,这就是为什么我们提出这个案例,以及文献综述。
Cryoglobulins are immunoglobulins that precipitate at temperatures below 37 °C and dissolve upon reheating. They can induce small-vessel vasculitis with renal involvement. Cryoglobulinemic glomerulonephritis is a rare manifestation that occurs in patients with monoclonal gammopathy, specifically Waldenström\'s macroglobulinemia. We present the case of a 52-year-old patient with a history of cutaneous vasculitis and hypothyroidism, who presented with generalized edema, moderate anemia, hypercholesterolemia, nephrotic range proteinuria of 12.69 g/day, microhematuria, arterial hypertension, and hypocomplementemia via the classical pathway, without acute kidney injury and with negative serological studies and positive cryoglobulins in the second determination. Serum and urine protein electrophoresis and immunofixation studies showed a monoclonal band of IgM and kappa light chain. Renal biopsy was consistent with cryoglobulinemic glomerulonephritis. In the context of dysproteinemia and cryoglobulinemic glomerulonephritis, bone-marrow aspiration and biopsy were performed, leading to the diagnosis of Waldenström\'s macroglobulinemia. Monoclonal gammopathies have been described in association with type I cryoglobulinemias. This described association is uncommon, which is why we present this case, along with a review of the literature.