[Clinical characteristics of 24 cases of immune checkpoint inhibitors-induced type 1 diabetes]

Objective: To analyze the clinical characteristics of immune checkpoint inhibitor (ICI)-induced type 1 diabetes (T1D). Methods: This was a retrospective case series study of clinical data from 24 patients with ICI-T1D admitted to People's Hospital of Henan Provincial between January 2018 and December 2024. The data collected included demographic characteristics, ICI usage, clinical manifestations, laboratory test results, and clinical outcome. Patients were categorized into mild and severe groups based on disease severity. Clinical characteristics between the two groups were compared using the Mann-Whitney U test. Results: Of the 24 patients, 21 (87.5%) were male and 3 (12.5%) were female, with an average age of (62.0±10.6) years. Patients in the severe disease group were significantly older than those in the mild disease group [(68.0±9.5) years vs. (58.4±9.8) years, P<0.05]. Compared to patients with mild disease, those with severe disease had significantly higher rates of impaired consciousness (9/9 vs.2/15), shorter ICI treatment cycles [3 (2, 6) vs. 6 (5, 8)], shorter time from ICI initiation to diabetes diagnosis [68 (31, 168) d vs. 162 (135, 235) d], and shorter time from the onset of diabetes symptoms to medical consultation [4 (2, 5) d vs. 8 (4, 26) d] (all P<0.05). The severe disease group also showed significantly higher blood glucose levels [43.0 (39.1, 57.3) mmol/L vs. 24.6 (19.6, 29.6) mmol/L] and a lower glycated hemoglobin level [6.8% (6.3%, 7.6%) vs. 7.9% (7.6%, 8.6%)], along with a higher incidence of fulminant T1D (8/9 vs. 2/15, all P<0.05). All patients received insulin injection therapy. After discharge, fasting C-peptide levels in 3 patients with mild disease showed a transient increase to 0.26, 0.43, 0.49 nmol/L but declined again after six months. Conclusions: ICI-T1D is characterized by acute onset and rapid progression. Older patients are more likely to develop severe disease. All patients require insulin therapy.