Leukocyte chemotaxis in diabetic patients and their nondiabetic first-degree relatives.

Leukocyte chemotaxis wasmeasured in 108 subjects: 20 normal controls, 36 insulin-taking diabetics (15 being index patients), and 52 nondiabetic first-degree relatives of index patients. The relatives had a mean chemotactic index (CI) significantly lower than that of the controls (individually, 25 per cent had CIs lower than the lowest of the controls); and the diabetics had a mean CI significantly lower than that of the relatives. The impairment of leukocyte chemotaxis measured in the first-degree relatives of diabetic index patients does not appear to be associated with an increased susceptibility to infection and suggests that the impaired leukotaxis is due to an inherent defect--perhaps genetic--in leukocyte function.