Immunoprotection in spontaneous remission of type 1 diabetes: long-term follow-up results

This prospective pilot study was undertaken to test the efficacy of oral methyl-prednisolone (MP) therapy at spontaneous remission phase of type 1 diabetes in intervening the course of the disease. Twenty-five type 1 diabetic patients who were classified as having a spontaneous remission (honeymoon) were divided into treatment and non-treatment groups on voluntary basis. Fifteen patients thus making up the treatment group (13 males and 2 females, mean age 23.8 +/- 6.2 years) received 0.7-1.0 mg/kg/day of MP p.o. for 2 weeks. The dose of the drug was then gradually diminished every week until 5 mg/day (approx. 0.1 mg/kg/day) and discontinued at 10 +/- 2 weeks. In case of hyperglycemia occurring in 12 of 15 patients due to the administration of steroid, insulin was used to normalize blood glucose levels (average 0.47 +/- 0.21 IU/kg/day). The non-treatment group (8 males and 2 females, mean age 21.8 +/- 8.9) did not receive any special medication or placebo except for insulin whenever necessary to regulate glycemia. Upon completion of protocol, all patients in treatment group displayed clinical remission with 10 still in non-insulin requiring remission for follow-up periods ranging between 16 and 91 months. The remaining 5 patients relapsed within 3-15 months of therapy. Other metabolic (including basal and stimulated C-peptide levels) and immunological indices that have spontaneously ameliorated with the occurrence of honeymoon were also maintained within normal range in the NIR patients. Meanwhile, natural remission in the non-MP-treated group terminated at 3.4 +/- 0.6 months with deterioration of all metabolic and immunological markers as well as increasing requirements for insulin. In conclusion, the spontaneous remission of the patients could be prolonged significantly by MP therapy as opposed to no therapy (P < 0.001). These results suggest that the spontaneous remission phase may be a crucial point of intervention in immunotherapy of type 1 diabetes and that randomized trials with MP at this particular phase would be worthwhile.