Summary

Insulin autoimmune syndrome (Hirata’s disease) is a disorder caused by development of autoantibodies to insulin and manifested by hypoglycaemic syndrome. The overwhelming majority of physicians do not include it in the differential diagnosis of hypoglycaemic states because of a misconception of an extremely low prevalence of this condition. This results in unnecessary drug therapy and unjustified surgical interventions in patients that otherwise would be successfully treated conservatively. This disease is strongly associated with certain alleles of the HLA gene. In most cases, this condition develops in predisposed individuals taking drugs containing sulfhydryl groups. Formation of autoantibodies to insulin may be observed in patients with other autoimmune disorders, as well as in those with multiple myeloma or monoclonal gammopathy of undetermined significance. This paper presents the first Russian case report of insulin autoimmune syndrome in an adult patient.

Learning points:

• Insulin autoimmune syndrome, Hirata’s disease, anti-insulin antibodies, and hypoglycaemia.

Summary

A 72-year-old man with no history of diabetes was referred to our department due to hyperglycemia during pembrolizumab treatment for non-small-cell lung carcinoma. His blood glucose level was 209 mg/dL, but he was not in a state of ketosis or ketoacidosis. Serum C-peptide levels persisted at first, but gradually decreased, and 18 days later, he was admitted to our hospital with diabetic ketoacidosis (DKA). The patient was diagnosed with fulminant type 1 diabetes (FT1D) induced by pembrolizumab. According to the literature, the insulin secretion capacity of a patient with type 1 diabetes (T1D) induced by anti-programmed cell death-1 (anti-PD-1) antibody is depleted in approximately 2 to 3 weeks, which is longer than that of typical FT1D. Patients with hyperglycemia and C-peptide persistence should be considered for hospitalization or frequent outpatient visits with insulin treatment because these could indicate the onset of life-threatening FT1D induced by anti-PD-1 antibodies. Based on the clinical course of this patient and the literature, we suggest monitoring anti-PD-1 antibody-related T1D.

Learning points:

• Immune checkpoint inhibitors, such as anti-PD-1 antibodies, are increasingly used as anticancer drugs. Anti-PD-1 antibodies can cause immune-related adverse events, including T1D.

• FT1D, a novel subtype of T1D, is characterized by the abrupt onset of hyperglycemia with ketoacidosis, a relatively low glycated hemoglobin level and depletion of C-peptide level at onset.

• In patients being treated with anti-PD-1 antibody, hyperglycemia with C-peptide level persistence should be monitored through regular blood tests. Because of C-peptide persistence and mild hyperglycemia, it is possible to miss a diagnosis of life-threatening FT1D induced by anti-PD-1 antibody.

• In particular, in patients who have no history of diabetes, hyperglycemia without DKA is likely to be the very beginning of anti-PD-1 antibody-induced T1D. Therefore, such patients must be considered for either hospitalization or frequent outpatient visits with insulin injections and self-monitoring of blood glucose.

Summary

Type B insulin resistance syndrome (TBIRS) is a very rare autoimmune disorder with polyclonal autoantibodies against the insulin receptor, resulting in severe and refractory hyperglycemia. Described here is a patient who within a few months after the onset of autoimmune type 1 diabetes increased her insulin requirements more than 20-fold; despite this she had considerable difficulty maintaining a plasma glucose value of <40–60 mmol/L (720–1100 mg/dL). On suspicion of TBIRS, the patient was started on tapering dose of glucocorticoids to overcome the autoimmune insulin receptor blockade, resulting in an immediate and pronounced effect. Within days, insulin requirements decreased by 80–90% and plasma glucose stabilized around 7–8 mmol/L (126–144 mg/dL). The presence of antibodies to the insulin receptor was detected by immunoprecipitation and binding assays. After a 4-month remission on low maintenance dose prednisolone, the patient relapsed, which required repeated plasmaphereses and immune column treatments with temporarily remarkable effect. Mixed and transient results were seen with rituximab, mycophenolic acid and bortezomib, but the glycemic status remained suboptimal. Lack of compliance and recurrent infections may have contributed to this.

Learning points:

• Type B insulin resistance syndrome (TBIRS) is a very rare autoimmune disorder with acquired polyclonal autoantibodies against the insulin receptor, resulting in severe and refractory hyperglycemia.

• We describe here a young patient in whom, a few months after the onset of a regular autoimmune diabetes, insulin requirements in a short time increased more than 20-fold, but despite this, the plasma glucose level could be kept at <40–60 mmol/L only with considerable difficulty. Did this patient have TBIRS?

• On suspicion of TBIRS, the patient was started on tapering glucocorticoids to overcome the autoimmune insulin receptor blockade, resulting in an immediate and pronounced effect; within days insulin requirements decreased by 80–90% and plasma glucose stabilized around 7–8 mmol/L.

• The presence of antibodies to the insulin receptor was detected by immunoprecipitation and binding assays.

  After a 4-month remission on low maintenance dose prednisolone, the patient relapsed, which required repeated plasmaphereses with temporarily remarkable effect.

• TBIRS should be considered in diabetic patients whose glycemia and/or insulin requirements are inexplicably and dramatically increased.

Summary

A patient with atypical partial lipodystrophy who had a transient initial response to metreleptin experienced acute worsening of her metabolic state when neutralizing antibodies against metreleptin appeared. Because her metabolic status continued to deteriorate, a therapeutic trial with melanocortin-4 receptor agonist setmelanotide, that is believed to function downstream from leptin receptor in the leptin signaling system, was undertaken in an effort to improve her metabolic status for the first time in a patient with lipodystrophy. To achieve this, a compassionate use (investigational new drug application; IND) was initiated (NCT03262610). Glucose control, body fat by dual-energy X-ray absorptiometry and MRI, and liver fat by proton density fat fraction were monitored. Daily hunger scores were assessed by patient filled questionnaires. Although there was a slight decrease in hunger scales and visceral fat, stimulating melanocortin-4 receptor by setmelanotide did not result in any other metabolic benefit such as improvement of hypertriglyceridemia or diabetes control as desired. Targeting melanocortin-4 receptor to regulate energy metabolism in this setting was not sufficient to obtain a significant metabolic benefit. However, complex features of our case make it difficult to generalize these observations to all cases of lipodystrophy. It is still possible that melanocortin-4 receptor agonistic action may offer some therapeutic benefits in leptin-deficient patients.

Learning points:

• A patient with atypical lipodystrophy with an initial benefit with metreleptin therapy developed neutralizing antibodies to metreleptin (Nab-leptin), which led to substantial worsening in metabolic control. The neutralizing activity in her serum persisted for longer than 3 years.

• Whether the worsening in her metabolic state was truly caused by the development of Nab-leptin cannot be fully ascertained, but there was a temporal relationship. The experience noted in our patient at least raises the possibility for concern for substantial metabolic worsening upon emergence and persistence of Nab-leptin. Further studies of cases where Nab-leptin is detected and better assay systems to detect and characterize Nab-leptin are needed.

• The use of setmelanotide, a selective MC4R agonist targeting specific neurons downstream from the leptin receptor activation, was not effective in restoring metabolic control in this complex patient with presumed diminished leptin action due to Nab-leptin.

• Although stimulating the MC4R pathway was not sufficient to obtain a significant metabolic benefit in lowering triglycerides and helping with her insulin resistance as was noted with metreleptin earlier, there was a mild reduction in reported food intake and appetite.

• Complex features of our case make it difficult to generalize our observation to all leptin-deficient patients. It is possible that some leptin-deficient patients (especially those who need primarily control of food intake) may still theoretically benefit from MC4R agonistic action, and further studies in carefully selected patients may help to tease out the differential pathways of metabolic regulation by the complex network of leptin signaling system.

Summary

This case report describes a family pedigree of a mother and her children with an E227K mutation in the KCNJ11 gene. People with this particular gene mutation typically present with transient neonatal diabetes; with more than half the cohort relapsing into permanent diabetes in adolescence or early adulthood. However, the mother developed diabetes as an adolescent and thus was initially diagnosed as having Type 1 Diabetes. All her children have inherited the same genetic mutation but with differing presentations. Her second, third and fourth child presented with transient neonatal diabetes which remitted at varying times. Her first child is 16 years old but had not developed diabetes at the time of writing. The KCNJ11 gene codes for the KIR6.2 subunit of the K_ATP channels of the pancreatic beta cells. Mutations in this gene limit insulin release from beta cells despite high blood glucose concentrations. Most people with diabetes caused by this genetic mutation can be successfully managed with glibenclamide. Learning of the genetic mutation changed the therapeutic approach to the mother’s diabetes and enabled rapid diagnosis for her children. Through this family, we identified that an identical genetic mutation does not necessarily lead to the same diabetic phenotype. We recommend clinicians to consider screening for this gene in their patients whom MODY is suspected; especially in those presenting before the age of 25 who remain C-peptide positive.

Learning points:

• K_ATP channel closure in pancreatic beta cells is a critical step in stimulating insulin release. Mutations in the KIR6.2 subunit can result in the K_ATP channels remaining open, limiting insulin release.

• People with KCNJ11 mutations may not present with neonatal diabetes as the age of presentation of diabetes can be highly variable.

• Most affected individuals can be treated successfully with glibenclamide, which closes the K_ATP channels via an independent mechanism.

• All first degree relatives of the index case should be offered genetic testing, including asymptomatic individuals. Offspring of affected individuals should be monitored for neonatal diabetes from birth.

• Affected individuals will require long-term follow-up as there is a high risk of recurrence in later life.

Summary

Durvalumab is a programmed cell death ligand 1 inhibitor, which is now approved in Australia for use in non-small-cell lung and urothelial cancers. Autoimmune diabetes is a rare immune-related adverse effect associated with the use of immune checkpoint inhibitor therapy. It is now being increasingly described reflecting the wider use of immune checkpoint inhibitor therapy. We report the case of a 49-year-old female who presented with polyuria, polydipsia and weight loss, 3 months following the commencement of durvalumab. On admission, she was in severe diabetic ketoacidosis with venous glucose: 20.1 mmol/L, pH: 7.14, bicarbonate 11.2 mmol/L and serum beta hydroxybutyrate: >8.0 mmol/L. She had no personal or family history of diabetes or autoimmune disease. Her HbA1c was 7.8% and her glutamic acid decarboxylase (GAD) antibodies were mildly elevated at 2.2 mU/L (reference range: <2 mU/L) with negative zinc transporter 8 (ZnT8) and islet cell (ICA) antibodies. Her fasting C-peptide was low at 86 pmol/L (reference range: 200–1200) with a corresponding serum glucose of 21.9 mmol/L. She was promptly stabilised with an insulin infusion in intensive care and discharged on basal bolus insulin. Durvalumab was recommenced once her glycaemic control had stabilised. Thyroid function tests at the time of admission were within normal limits with negative thyroid autoantibodies. Four weeks post discharge, repeat thyroid function tests revealed hypothyroidism, with an elevated thyroid-stimulating hormone (TSH) at 6.39 mIU/L (reference range: 0.40–4.80) and low free T4: 5.9 pmol/L (reference range: 8.0–16.0). These findings persisted with repeat testing despite an absence of clinical symptoms. Treatment with levothyroxine was commenced after excluding adrenal insufficiency (early morning cortisol: 339 nmol/L) and hypophysitis (normal pituitary on MRI).

Learning points:

• Durvalumab use is rarely associated with fulminant autoimmune diabetes, presenting with severe DKA.

• Multiple endocrinopathies can co-exist with the use of a single immune checkpoint inhibitors; thus, patients should be regularly monitored.

• Regular blood glucose levels should be performed on routine pathology on all patients on immune checkpoint inhibitor.

• Clinician awareness of immunotherapy-related diabetes needs to increase in an attempt to detect hyperglycaemia early and prevent DKA.

Summary

We report the renal histology of a 66-year-old man with hypertension, cardiovascular disease, and a 30-year history of type 2 diabetes mellitus with proliferative diabetic retinopathy, diabetic neuropathy, and diabetic foot status post toe amputation. Urinary protein excretion was 1.4 g/gCr, serum creatinine level 0.86 mg/dL, estimated glomerular filtration rate 69 mL/min/1.73 m², and HbA1c 13–15%, despite using insulin. Light microscopy showed global glomerulosclerosis in 37% of the glomeruli, but the remaining glomeruli were intact. Significant polar vasculosis was present, while arteriolar sclerosis was mild. Electron microscopy revealed a thickened glomerular basement membrane, which is compatible with the early stage of diabetic glomerulopathy. The presented case was unique because glomerular changes seen typically in diabetes were not seen in the patient, despite the long-standing history of diabetes and diabetic comorbidities, while prominent polar vasculosis was found. Polar vascular formation helps preserve the glomeruli by allowing hyperosmotic blood bypass the glomeruli; this decreases intraglomerular pressure and minimizes glomerular endothelial damage.

Learning points:

• A 66-year-old man with a 30-year history of type 2 diabetes mellitus with poor glycemic control underwent renal biopsy, which showed scarce glomerular changes typically seen in diabetic kidney disease and instead revealed significant polar vasculosis.

• Past studies demonstrated that the increased small vessels around the vascular hilus in diabetic patients originated from the afferent arterioles and drained into the peritubular capillaries.

• Polar vascular formation may preserve glomerular function by allowing the blood flow to bypass the glomeruli and decreasing the intraglomerular pressure, which minimizes endothelial damage of the glomerular tufts.

Learning points:

• Patients treated with anti-PD-L1 should be screened for the most common immune-related adverse events (irAEs).

• Glucose levels and thyroid function should be monitored before and during the treatment.

• Durvalumab is mainly associated with thyroid and endocrine pancreas dysfunction.

• In the patients with significant autoimmune background, risk–benefit balance of antineoplastic immunotherapy should be accurately assessed.

Learning points:

• CVC insertion is one of the most significant risk factors for thrombosis in the paediatric population.

• Risk factors for CVC-associated thrombosis include increased duration of CVC placement, malpositioning and infusion of blood products.

• To our knowledge, this is the first study to evaluate CVC-associated thrombosis in patients with congenital hyperinsulinism (CHI).

• The incidence of CVC-associated thrombosis development is significant (18%) in CHI patients and higher compared to other neonates with CVC. CHI severity may be a risk factor for thrombosis development.

• Although effective prophylaxis for CVC-associated thrombosis in infancy is yet to be established, our preliminary experience suggests the safety and efficacy of enoxoaparin prophylaxis in this population and requires on-going evaluation.

Learning points:

• The incidence of T1DM with pembrolizumab treatment is being increasingly recognised and reported, and DKA is a common initial presentation.

• Physicians should counsel patients about this potential irAE and educate them about the symptoms of hyperglycaemia and DKA.

• The ESMO guidelines recommend regular monitoring of blood glucose in patients treated with ICIs, a recommendation needs to be incorporated into cancer treatment protocols for pembrolizumab and other ICIs in order to detect hyperglycaemia early and prevent DKA.