Slowly progressive type 1 diabetes treated with metformin for five years after onset

Slow progression of type 1 diabetes associated with pembrolizumab and lenvatinib combination therapy in a patient with probable slowly progressive type 1 diabetes mellitus and endometrial cancer

A 58-year-old woman with a body mass index of 26.4 kg/m2 was referred because of high glycated hemoglobin (HbA1c) at a medical checkup. Her anti-glutamic acid decarboxylase antibody (GADA) titer was positive (16.0 U/mL; normal < 5.0 U/mL). Her HbA1c was controlled at 6.4%-7.5% using metformin, ipragliflozin, and sitagliptin. Two-and-a-half years later, she was diagnosed with endometrial cancer with pelvic lymph node metastasis and underwent surgery followed by chemotherapy with carboplatin and paclitaxel, then carboplatin and docetaxel. However, owing to enlargement of the metastatic nodules, combination therapy with pembrolizumab and lenvatinib (pem + len) was initiated (DAY 1). On DAY 36, her plasma glucose (PG) concentration was high; therefore, insulin degludec was administered once daily and self-monitoring of blood glucose commenced. On DAY 50, her PG and HbA1c were 509 mg/dL and 10.2%, respectively, and her insulin therapy was changed to a basal-bolus. Urinary ketones were negative. Treatment with pem + len was continued without interruption. Her GADA was negative 3 months before starting pem + len (DAY - 119), but was high (234 U/mL) on DAY 50, and then negative on DAYs 345 and 670. Her serum C-peptide concentration gradually decreased, but it did not disappear (DAYs - 119, 50, 156, 345, 607 and 670: 2.49, 1.80, 0.90, 0.21, 0.85 and 0.65 ng/mL, respectively). Human leukocyte antigen analysis revealed two susceptibility haplotypes (DRB1*04:05-DQB1*04:01-DPB1*02:01 and DRB1*04:05-DQB1*04:01-DPB1*05:01) for type 1 diabetes (T1D). This case is notable in that pembrolizumab-related T1D progressed more slowly than previously reported, and lenvatinib may have contributed to this delay.

Slowly Progressive Type 1 Diabetes Mellitus: Current Knowledge And Future Perspectives

Slowly progressive type 1 insulin-dependent diabetes mellitus (SPIDDM), sometimes referred to as latent autoimmune diabetes in adults (LADA), is a heterogeneous disease that is often confused with type 1 and type 2 diabetes. As a result, there were few diagnostic criteria for this disorder until 2012, when the Japan Diabetes Society established criteria that could be used in clinical practice. A primary question is whether pathologic markers for type 1 or type 2 diabetes are present in the pancreas of patients with SPIDDM, because the phenotype of SPIDDM is similar to both type 1 and type 2 diabetes. Recent studies clarified pathologic findings in the pancreas of patients with SPIDDM, which included T-cell-mediated insulitis, a marker of type 1 diabetes; pseudoatrophic islets (islets specifically devoid of beta cells), another hallmark of type 1 diabetes; and a lack of amylin (ie, islet amyloid polypeptide) deposition to the islet cells, a pathologic marker of type 2 diabetes. In terms of preventing the loss of beta-cell function in patients with SPIDDM, several studies have shown that some drugs, including dipeptidyl peptidase-4 inhibitors, are effective. There is an increased need for early diagnosis of SPIDDM to preserve beta-cell function. This review presents updated findings on the pathogenesis and immunologic findings of the affected pancreas, diagnostic markers, risk factors for progression of beta-cell dysfunction, epidemiology, clinical features, diagnostic strategies, prevention strategies, and clinical options for patients with SPIDDM.

Distinct Inflammatory Changes of the Pancreas of Slowly Progressive Insulin-dependent (Type 1) Diabetes

OBJECTIVE

The aim of this study was to identify the distinct pathological changes on the endocrine and exocrine pancreas of slowly progressive insulin-dependent diabetes mellitus (SPIDDM) or latent autoimmune diabetes in adults.

METHODS

The pancreases from 12 islet autoantibody-positive SPIDDM patients and 19 age-matched subjects with no diabetes were examined histologically for islet inflammation/insulitis, expressions of cytokines, and enterovirus VP1 protein, exocrine pancreatic inflammation, pancreatic ductal changes, major histocompatibility complex class I hyperexpression, and amylin-positive amyloid in the islets.

RESULTS

Insulitis dominant for CD8 T-cells and CD68 macrophages was observed in all SPIDDM cases irrespective of duration of diabetes and weight of residual beta cells. Major histocompatibility complex class I hyperexpression on residual beta cells was observed in SPIDDM. All SPIDDM exocrine pancreases showed extensive inflammation, dilated pancreatic ducts, and periductal fibrosis. As many as 75% (9/12) of pancreases had pancreatic intraepithelial neoplasia, which is assumed to be associated with ductal obstruction/narrowing and exocrine pancreatic inflammation, in SPIDDM. Amylin-positive amyloid deposition was not detected in SPIDDM.

CONCLUSIONS

Persistent insulitis with preserved beta cells and major histocompatibility complex class I hyperexpression and exocrine pancreatic inflammation with pancreatic intraepithelial neoplasia are distinct histological features of SPIDDM pancreas.

Possible Long-Term Efficacy of Sitagliptin, a Dipeptidyl Peptidase-4 Inhibitor, for Slowly Progressive Type 1 Diabetes (SPIDDM) in the Stage of Non-Insulin-Dependency: An Open-Label Randomized Controlled Pilot Trial (SPAN-S)

INTRODUCTION

We tested the hypothesis that dipeptidyl peptidase-4 (DPP-4) inhibitors are effective in preserving the β-cell function for long-term periods in patients with slowly progressive type 1 diabetes (SPIDDM) or latent autoimmune diabetes in adults (LADA).

METHODS

In the present open-label, randomized, controlled trial, 14 non-insulin-requiring diabetic patients with glutamic acid decarboxylase autoantibodies (GADAb) were randomly assigned to receive either sitagliptin (S group) or pioglitazone (P group). As a historical control, the Tokyo Study, in which non-insulin-dependent patients with SPIDDM were assigned to receive treatment by either insulin or sulfonylurea (SU), was used.

RESULTS

On average, the ∑C-peptide values during the oral glucose tolerance test through the follow-up periods showed a nonsignificant increase in the S group (n = 6, n = 5 at 48 months) compared to the P group (n = 5, n = 2 at 48 months). In comparison to the data in the Tokyo Study, treatment by sitagliptin significantly influenced the longitudinal changes in the ∑C-peptide values with a more increased direction than insulin or SU, especially in patients with 48 months of follow-up (p = 0.014 and p = 0.007, respectively). Although the titers of GADAb were not significantly different between the S and P groups during the study, the change ratio of the GADAb titers from baseline was significantly inversely correlated with the change ratio of the ∑C-peptide values from baseline in the S group (p = 0.003); in particular, when the GADAb titers decreased from baseline, the ∑C-peptide values frequently increased.

CONCLUSION

The present pilot trial suggests that treatment of SPIDDM/LADA by sitagliptin, a DPP-4 inhibitor, may be more effective in preserving the β-cell function than insulin treatment for at least 4 years, possibly through the immune modulatory effects of DPP-4 inhibitors.

CLINICAL TRIAL REGISTRATION

Japanese Clinical Trials Registry UMIN000003693.