Titers of CH5O were assayed in 30 JOD (juvenile-onset diabetics with insulin-dependency) and 4 MODY (maturity-onset diabetics among young people). In patients with a JOD history of less than 3 years, the CH5O titer was significantly lower than that in patients with a history of more than 5 years. The CH5O titer in JOD patients with a duration of from 5 to 10 years did not differ significantly from that in JOD patients with a history of more than 10 years. The CH5O titer in patients with a JOD history of less than 5 years was significantly lower than that in MODY patients, who had an almost identical duration. These results suggest involvement of the complement system in the earlier phase of JOD.
The contaminating Proinsulin-Like Immunoreactivity (PLI) in a monospecies porcine NPH insulin preparation (lot. IS1) was determined directly and after gel filtration by proinsulin-specific radioimmunoassay (porcine). Although eluate of 500 ng of monospecies insulin did not reveal Proinsulin-Like Component (PLC), apparent PLC was detected after gel filtration of 5, 000 ng of this insulin preparation by the specific radioimmunoassay. The monospecies insulin preparation contained 0.04% of porcine PLI by weight as estimated directly utilizing the specific radioimmunoassay for porcine PLI. In 6 diabetics treated with monospecies porcine NPH insulin preparation from the beginning of insulin treatment, porcine or bovine proinsulin-specific antibodies were not detectable throughout the insulin treatment for 3 to 12 months. One case out of 6 insulin treated diabetics developed porcine insulin antibodies after 2 months of the treatment. Porcine or bovine insulin antibodies were not detectable after 3 to 12 months of insulin treatment in 5 out of 6 diabetics.