1921-2021: From insulin discovery to islet transplantation in type 1 diabetes

Islet transplantation-immunological challenges and current perspectives

Pancreatic islet transplantation is a minimally invasive procedure aiming to reverse the effects of insulin deficiency in patients with type 1 diabetes (T1D) by transplanting pancreatic beta cells. Overall, pancreatic islet transplantation has improved to a great extent, and cellular replacement will likely become the mainstay treatment. We review pancreatic islet transplantation as a treatment for T1D and the immunological challenges faced. Published data demonstrated that the time for islet cell transfusion varied between 2 and 10 h. Approximately 54% of the patients gained insulin independence at the end of the first year, while only 20% remained insulin-free at the end of the second year. Eventually, most transplanted patients return to using some form of exogenous insulin within a few years after the transplantation, which imposed the need to improve immunological factors before transplantation. We also discuss the immunosuppressive regimens, apoptotic donor lymphocytes, anti-TIM-1 antibodies, mixed chimerism-based tolerance induction, induction of antigen-specific tolerance utilizing ethylene carbodiimide-fixed splenocytes, pretransplant infusions of donor apoptotic cells, B cell depletion, preconditioning of isolated islets, inducing local immunotolerance, cell encapsulation and immunoisolation, using of biomaterials, immunomodulatory cells, etc.

Evaluation of Lipohypertrophy in Patients With Type 1 Diabetes Mellitus on Multiple Daily Insulin Injections or Continuous Subcutaneous Insulin Infusion

OBJECTIVE

To determine lipohypertrophy (LH) in patients with type 1 diabetes mellitus (T1DM) on multiple daily insulin injections (MDII) or continuous subcutaneous insulin infusion (CSII) and to reveal the factors associated with the development and severity of LH.

METHODS

Sixty-six patients with T1DM treated with MDII (n = 35, 53%) or CSII (n = 31, 47%) for at least 1 year were included. LH localizations were detected with palpation and ultrasonography (USG).

RESULTS

The LH detection rate with USG was significantly higher than that by palpation in the whole group (P < .001). The LH was detected with USG in 30 (85.7%) patients in the MDII group and 22 (71.0%) patients in the CSII group (P = .144). Advanced LH was detected in 13 (37.1%) of the patients treated with MDII and in 3 (9.7%) of the patients treated with CSII. LH was more severe in the MDII group than in the CSII group (P = .013). Diabetes duration and length of infusion set use were significantly longer and body mass index, hypoglycemia, and complication rates were higher in patients with LH than those in patients without LH (P < .05). A positive correlation was found between LH severity and HbA1C and insulin dose (P < .05, for both). MDII as insulin administration method, incorrect rotation, and a history of ketosis were found to be the most related factors with LH severity in a multiple linear regression analysis (P < .05).

CONCLUSION

USG might be an effective approach for detecting and evaluating the severity of LH. MDII might cause more severe LH than CSII in patients with T1DM. In this study, LH was found to be associated mostly with incorrect rotation technique and a history of ketosis.

Predictors of change in hypoglycemia unawareness among patients with type 1 diabetes

AIMS

To analyse predictors of hypoglycemia unawareness (HU) and improvement in Clarke score in clinical practice.

MATERIALS AND METHODS

We retrospectively identified patients with type 1 diabetes (T1D) at an academic T1D clinic who completed HU surveys 6-12 months apart. HU (Clarke score ≥4) and improvement in Clarke score (decrease by ≥1 point or more clinically relevant ≥2 point) were assessed in univariable relationships and using multivariable logistic regression.

RESULTS

Of the 300 participants, median diabetes duration was 19 years, 47 had HU at baseline, and 91 had an improvement by 1 point while 21 had an improvement by 2 points. Patients with baseline Clarke score ≥4 who had ≥1 or ≥2 point improvement had lower filtration rate (eGFR) than those who did not. After adjustment for other variables, gender (male OR 0.33, 95% CI 0.15, 0.74), log diabetes duration (OR 6.40, 95% CI 2.84, 14.5), and eGFR <60 ml/min/1.73 m² (5.56, 95% CI 1.98, 15.6) were independent predictors of baseline HU. Continuous glucose monitoring use (OR 2.04, 95% CI 1.20, 3.48) and log diabetes duration (OR 1.78, 95% CI 1.22, 2.60) were independent predictors of 1 point improvement and eGFR <60 ml/min/1.73 m² (OR 10.5, 95% CI 3.64, 30.0) and an education visit (OR 2.64, 95% CI 1.01, 6.89) were independent predictors of 2 point improvement in Clarke score.

CONCLUSIONS

Diabetes duration, gender, and eGFR were independent predictors of HU. Improvement in Clarke score is possible in patients with long-standing T1D, underscoring the need for additional study.