Type 1 diabetes mellitus (T1DM) is an autoimmune disorder that affects an estimated 30 million people worldwide. It is characterized by the destruction of pancreatic β cells by the immune system, which leads to lifelong dependency on exogenous insulin and imposes an enormous burden on patients and health-care resources. T1DM is also associated with an increased risk of comorbidities, such as cardiovascular disease, retinopathy, and diabetic kidney disease (DKD), further contributing to the burden of this disease. Although T cells are largely considered to be responsible for β-cell destruction in T1DM, increasing evidence points towards a role for B cells in disease pathogenesis. B cell-depletion, for example, delays disease progression in patients with newly diagnosed T1DM. Loss of tolerance of islet antigen-reactive B cells occurs early in disease and numbers of pancreatic CD20⁺ B cells correlate with β-cell loss. Although the importance of B cells in T1DM is increasingly apparent, exactly how these cells contribute to disease and its comorbidities, such as DKD, is not well understood. Here we discuss the role of B cells in the pathogenesis of T1DM and how these cells are activated during disease development. Finally, we speculate on how B cells might contribute to the development of DKD.

1 型糖尿病 (T1DM) 是一种自身免疫性疾病，影响全球约 3000 万人。其特点是免疫系统破坏胰岛β细胞，导致终生依赖外源性胰岛素，给患者和医疗资源带来巨大负担。T1DM 还与合并症风险增加有关，例如心血管疾病、视网膜病变和糖尿病肾病 (DKD)，进一步加重了这种疾病的负担。尽管 T 细胞在很大程度上被认为是 T1DM 中 β 细胞破坏的原因，但越来越多的证据表明 B 细胞在疾病发病机制中的作用。例如，B 细胞耗竭延缓了新诊断的 T1DM 患者的疾病进展。⁺ B 细胞与 β 细胞丢失相关。尽管 B 细胞在 T1DM 中的重要性越来越明显，但这些细胞究竟如何导致疾病及其合并症（如 DKD）尚不清楚。在这里，我们讨论 B 细胞在 T1DM 发病机制中的作用以及这些细胞在疾病发展过程中如何被激活。最后，我们推测 B 细胞如何促进 DKD 的发展。