McLeod B C, Sassetti R J
Arch Intern Med. 1984 Jul;144(7):1381-5. doi: 10.1001/archinte.144.7.1381.
Three patients with cutaneous vasculitis and one patient with digital gangrene had a negative or equivocal test for cryoglobulins but a positive result in a modified assay for cryoproteins ( hypocryoglobulins [ HGs ]) in which serum is rendered hypotonic by dilution with an equal volume of distilled water before incubation in the cold. Each cryoprecipitate contained a mixture of immunoglobulins, and in two instances, a monoclonal component was demonstrated. Rheumatoid factor activity was found in two precipitates. All four patients improved with plasmapheresis, and two subsequently responded to alkylating agents. Seven patients with conventional cryoglobulins had precipitation from diluted serum as well, but none had a substantial increase in precipitation in the HG assay. Only two of five patients with seropositive rheumatoid arthritis had abnormal levels of HG. Hypocryoglobulins are a new category of abnormally insoluble serum proteins, probably closely related to conventional cryoglobulins, which are readily detected in a simple precipitation assay.
三名皮肤血管炎患者和一名手指坏疽患者的冷球蛋白检测结果为阴性或不确定，但在一种改良的冷蛋白检测（低冷球蛋白[HG]）中结果为阳性，该检测方法是在冷孵育前用等体积蒸馏水稀释血清使其成为低渗状态。每份冷沉淀物都含有免疫球蛋白混合物，在两个病例中还证实有单克隆成分。在两份沉淀物中发现了类风湿因子活性。所有四名患者经血浆置换后病情改善，其中两名随后对烷化剂有反应。七名传统冷球蛋白血症患者的稀释血清也有沉淀，但在HG检测中沉淀均未显著增加。五名血清阳性类风湿关节炎患者中只有两名HG水平异常。低冷球蛋白是一类新的异常不溶性血清蛋白，可能与传统冷球蛋白密切相关，可通过简单的沉淀试验轻易检测到。
