Heterophile antibodies segregate in families and are associated with protection from type 1 diabetes

Abstract

Markedly elevated levels of serum IL-4 were reported previously in 50% of a small group of type 1 diabetes nonprogessors. To determine the patterns of expression for this phenotype, a larger cohort of 58 families containing type 1 diabetic patients was examined. Analysis of the two-site ELISA assay used to measure serum IL-4 revealed evidence for heterophile antibodies, i.e., nonanalyte substances in serum capable of binding antibodies mutivalently and providing erroneous analyte (e.g., IL-4) quantification. Interestingly, relatives without type 1 diabetes were significantly more likely to have this phenotype than were patients with the disease (P = 0.003). In addition, the trait appears to have clustered within certain families and was associated with the protective MHC allele DQB1*0602 (P = 0.008). These results suggest that heterophile antibodies represent an in vivo trait associated with self-tolerance and nonprogression to diabetes.

Figure 1

Analysis of serum cytokine and demonstration of heterophile antibody. The quantity of serum cytokine determined through two-site ELISA testing is influenced by the addition of serum from appropriate species (e.g., FBS) and may be inaccurately estimated as evidenced by analyses using mismatched anticytokine antibody pairings. Serum samples were obtained from a previously characterized series of diabetic probands and nondiabetic relatives (5, 15). By using a set of samples from eight subjects stratified according to presumed serum IL-4 levels, OD levels were identified in cases of (a) correct (i.e., IL-4 capture, IL-4 detection) or mismatched (b) [IL-4 capture, tumor necrosis factor β (TNF-β) detection] and (c) (IL-4 capture, IL-13 detection) antibody pairings. Assays were performed in the presence of BSA as well as FBS, as indicated.

Figure 2

The phenotype of heterophile antibodies clusters in families with type 1 diabetes. Serum samples and DNAs were obtained from a previously characterized cohort of multiplex and simplex families harboring diabetic probands and individuals with other autoimmune disorders (5, 15). Heterophile antibody levels were determined as described (11). The pedigrees for the five families that had two or more subjects with heterophile antibodies are pictured. Only one individual in these families had both type 1 diabetes and heterophile antibodies. The HLA-DQB1 alleles for each subject are pictured. Individual alleles for the DQB1*05 family were not further subtyped and are represented as 500. In addition, the diabetes-protective DQB1*0602 alleles are underlined (602).