Dapsone at onset of diabetes lowers glycated hemoglobin and delays death in NOD mice.

Dapsone (4,4'-diaminodiphenyl sulfone) is a compound that has a large clinical experience due to its antimicrobial effects against mycobacterium leprae, the causative agent of leprosy. It is increasingly used in a number of clinical situations where inflammation may play an ancillary role. An inhibitory effect of the drug or lack thereof in the cumulative incidence or propagation of diabetes mellitus in the NOD mouse has mechanistic as well as therapeutic implications. We previously showed that dapsone administered continuously as a percentage of food to NOD mice inhibits the cumulative incidence of diabetes in a dose dependent fashion. In the present experiment, female NOD litter mates were randomized to receive dapsone (0.001% w/w as a percentage of food) at onset of diabetes. There were no differences in weight, blood glucose, or glycated hemoglobin at 10 weeks of age among the animals that were ultimately to receive dapsone (n = 10), mouse chow alone (n = 9), or those who did not develop diabetes (n = 3). The mean time to onset of diabetes, mean blood glucose at onset, and mean glycated hemoglobin at onset did not differ between animals who did or did not receive dapsone. Animals receiving dapsone had significantly (p < or = 0.03) lower glycated hemoglobin at weeks 2, 3, and 4 following the onset of diabetes and lived significantly longer following diagnosis of diabetes (7 vs. 4 weeks, p < 0.05). In conclusion, dapsone modulates the progression of autoimmune diabetes in the NOD mouse even when administered after the initiation of hyperglycemia.