The present inventors investigated anti-IL-6 receptor antibodies for their effect in suppressing damage to transplanted islets after islet transplantation. As a result, they found that anti-IL-6 receptor antibodies reduced damage to transplanted islets, improved islet survival, and corrected hyperglycemia in recipients. Further, they revealed that administration of the anti-IL-6 receptor antibodies of the present invention suppressed the production of inflammatory cytokines by infiltrating cells after transplantation. Specifically, the present inventors discovered for the first time that damage to transplanted islets after islet transplantation can be suppressed by using anti-IL-6 receptor antibodies according to the present invention.
