Cold reacting anti-nuclear factor (ANF) in families of patients with IgA nephropathy.

The emergence of cold reacting anti-nuclear factor (ANF) in families of patients with IgA nephropathy was examined to determine whether some immunological alterations among family members affect the development of this disease. The procedure for the detection of the cold reacting ANF was reported previously. Fifty-five per cent of sera from 66 relatives of IgA nephropathy 24 patients was found to have the IgM cold reacting antibody. The incidence of ANF in healthy adults was 3%. Both household and non-household consanguineous relatives showed antibody in their sera. Sixty-five per cent of consanguineous relatives who had close household contacts with IgA nephropathy patients showed cold reacting ANF, whereas only 10% of non-consanguineous relatives who had close household contact had this antibody. It is suggested that familial susceptibility or genetic factors, in addition to environmental factors, may be responsible in the development of IgA nephropathy.