Wyatt R J, Julian B A, Weinstein A, Rothfield N F, McLean R H
J Clin Immunol. 1982 Apr;2(2):110-7. doi: 10.1007/BF00916894.
H (beta 1H) controls the C3b amplification loop by its ability to displace Bb from the alternative pathway convertase, C3b,Bb, and acts as a cofactor with I (C3b inactivator) to produce inactive C3b. Serum C3 levels are dependent to a large extent on the levels of H and I. Partial H deficiency was found in two families. The index case in Family 1 had vasculitis, thrombocytopenia, proteinuria, and depressed serum H and C3 levels. The index case in Family 2 had depressed serum H and B (Factor B) levels and IgA nephropathy which progressed to renal failure. His sister also had IgA nephropathy and depressed serum H and C3 levels. The depressed serum C3 level, B level, and H level could be responsible for the development of the immune diseases found in some members of these families.
H（β1H）通过其将Bb从替代途径转化酶C3b、Bb上置换下来的能力来控制C3b放大环，并作为I（C3b灭活剂）的辅因子产生无活性的C3b。血清C3水平在很大程度上取决于H和I的水平。在两个家族中发现了部分H缺乏症。家族1中的先证者患有血管炎、血小板减少症、蛋白尿，血清H和C3水平降低。家族2中的先证者血清H和B（因子B）水平降低，患有IgA肾病并进展为肾衰竭。他的妹妹也患有IgA肾病，血清H和C3水平降低。血清C3水平降低、B水平降低和H水平降低可能是这些家族中一些成员发生免疫疾病的原因。
