Per Medbøe ThorsbyInstitute of Clinical Medicine, University of Oslo, Oslo, Norway Hormone Laboratory, Department of Medical Biochemistry and Biochemical Endocrinology and Metabolism Research Group, Oslo University Hospital, Aker, Norway
We present a young woman with treatment resistant insulin autoimmune syndrome (IAS) with a protracted course. Her serum insulin level was 6945 pmol/l (<160), C-peptide 4042 pmol/L (<1480), anti-insulin antibodies 5305 U/mL (<0.4) were monoclonal IgG kappa. After 12 h of fasting, her blood glucose fell to 1.2 mmol/L. Post-meal blood glucose peaked at 12.2 mmol/L with reactive hypoglycaemia below 2 mmol/L. Frequent meals and continuous blood glucose monitoring were helpful, but further treatments advocated in the literature with prednisolone, rituximab, plasmapheresis, cyclophosphamide and ciclosporin were without beneficial effect.
Based on this case and a review of the literature, we propose that IAS is not one but two different diseases with different therapeutic strategies. The first disease, polyclonal IAS, predominates in Asia and is characterized by polyclonal anti-insulin antibodies, association with certain HLA genotypes and other autoimmune conditions, medications and viral infections possibly triggering the disease, a possible female predominance among young patients and a tendency towards spontaneous remission. The other disease, monoclonal IAS, predominates in Caucasians. Typical features are monoclonal anti-insulin antibodies, only weak HLA association, no drug predisposition, no sex difference, rare remission and conventional therapy often being without any clinical effect. We suggest that monoclonal IAS with IgG or IgA anti-insulin antibodies should receive therapy targeting plasma cells rather than lymphocytes.
IAS may be considered as two separate diseases, polyclonal and monoclonal.
The presence of either polyclonal or monoclonal antibodies should determine the choice of treatment for IAS.
In polyclonal IAS, discontinuation of a triggering medication and treatment of triggering conditions should be the backbone of therapy.
Monoclonal IAS should receive treatment targeting plasma cells.
Sarcoidosis is an inflammatory, multisystem disease with an undetermined etiology. The presence of noncaseating granulomas in involved organs is a characteristic pathomorphological feature. Sarcoidosis, like a chameleon, can mimic different medical conditions. Although the lungs are most commonly involved, extrapulmonary manifestations can influence any system. The clinical course of the disease may differ. Immediate initiation of glucocorticosteroid therapy is important when critical organs are impaired. A case of a patient with sarcoidosis whose first clinical symptoms were related to diabetes insipidus (DI) was presented. The diagnosis of multiple organ sarcoidosis was delayed because of an adequate response to treatment with vasopressin. The multidisciplinary diagnostic approach validated the involvement of the pituitary gland, lungs, lymph nodes, bones, and subcutaneous tissue. The presented case emphasizes the critical importance of the multifaceted differential diagnosis of patients with DI.
Sarcoidosis usually affects the lung but can also be a multisystemic disease.
The assessment of the extension of sarcoidosis remains complex.
A multidisciplinary approach must identify all-organ involvement and initiate appropriate sarcoidosis treatment.
Diabetes insipidus (DI) can be the first symptom of a systemic granulomatous disorder.
In the differential diagnosis of DI, a comprehensive assessment of rare causes of endocrine disorders, including extrapulmonary sarcoidosis, should be considered.
Immune checkpoint inhibitors are the mainstay of treatment for advanced melanoma, and their use is being increasingly implicated in the development of autoimmune endocrinopathies. We present a case of a 52-year-old man with metastatic melanoma on combination nivolumab and ipilumimab therapy who developed concurrent hypophysitis, type 1 diabetes mellitus (T1DM) and diabetes insipidus. He presented prior to third cycle of combination treatment with a headache, myalgias and fatigue. Biochemistry and MRI pituitary confirmed anterior pituitary dysfunction with a TSH: 0.02 mU/L (0.5–5.5 mU/L), fT4: 5.2 pmol/L (11–22 pmol/L), fT3: 4.0 pmol/L (3.2–6.4 pmol/L), cortisol (12:00 h): <9 nmol/L (74–286 nmol/L), FSH: 0.7 IU/L (1.5–9.7 IU/L), LH: <0.1 IU/L (1.8–9.2 IU/L), PRL: 1 mIU/L (90–400 mIU/L), SHBG: 34 nmol/L (19–764 nmol/L) and total testosterone: <0.4 nmol/L (9.9–27.8 nmol/L). High-dose dexamethasone (8 mg) was administered followed by hydrocortisone, thyroxine and topical testosterone replacement. Two weeks post administration of the third cycle, he became unwell with lethargy, weight loss and nocturia. Central diabetes insipidus was diagnosed on the basis of symptoms and sodium of 149 mmol/L (135–145 mmol/L). Desmopressin nasal spray was instituted with symptom resolution and normalization of serum sodium. Three weeks later, he presented again polyuric and polydipsic. His capillary glucose was 20.8 mmol/L (ketones of 2.4 mmol), low C-peptide 0.05 nmol/L (0.4–1.5 nmol/L) and HbA1c of 7.7%. T1DM was suspected, and he was commenced on an insulin infusion with rapid symptom resolution. Insulin antibodies glutamic acid decarboxylase (GAD), insulin antibody-2 (IA-2) and zinc transporter-8 (ZnT8) were negative. A follow-up MRI pituitary revealed findings consistent with recovering autoimmune hypophysitis. Immunotherapy was discontinued based on the extent of these autoimmune endocrinopathies.
The most effective regime for treatment of metastatic melanoma is combination immunotherapy with nivolumab and ipilumimab, and this therapy is associated with a high incidence of autoimmune endocrinopathies.
Given the high prevalence of immune-related adverse events, the threshold for functional testing should be low.
Traditional antibody testing may not be reliable to identify early-onset endocrinopathy.
Routine screening pathways have yet to be adequately validated through clinical trials.
A 65-year-old obese Caucasian woman presented with symptomatic postprandial hypoglycemic episodes, resolution of symptoms with carbohydrate intake and significantly elevated anti-insulin antibody levels. She did not have any evidence for the use of oral antidiabetic medications, insulin, herbal substances, performing strenuous exercise or history of bariatric surgery. Fingerstick blood glucose readings revealed blood sugar of 35 mg/dL and 48 mg/dL, when she had these symptoms. Her medical history was significant for morbid obesity, hypothyroidism and gastro esophageal reflux disease. Her home medications included levothyroxine, propranolol and omeprazole. A blood sample obtained during the symptoms revealed the following: fingerstick blood sugar 38 mg/dL, venous blood glucose 60 mg/dL (normal (n): 70–99 mg/dL), serum insulin 202 IU/mL (n: <21), proinsulin 31.3 pmol/L (n: <28.9), C-peptide 8 ng/mL (n: 0.9–7), beta-hydroxybutyrate 0.12 mmol/L (n: 0.02–0.27) anti-insulin antibody >45.4 U/mL (n: <0.4). The result obtained while screening for serum sulfonylurea and meglitinides was negative. The repeated episodes of postprandial hypoglycemia associated with significantly elevated anti-insulin antibodies led to a diagnosis of insulin antibody syndrome (IAS). Significant improvement of hypoglycemic symptoms and lower anti-insulin antibody levels (33 U/mL) was noted on nutritional management during the following 6 months. Based on a report of pantoprazole-related IAS cases, her omeprazole was switched to a H2 receptor blocker. She reported only two episodes of hypoglycemia, and anti-insulin antibody levels were significantly lower at 10 U/mL after the following 12-month follow-up.
Initial assessment of the Whipple criteria is critical to establish the clinical diagnosis of hypoglycemia accurately.
Blood sugar monitoring with fingerstick blood glucose method can provide important information during hypoglycemia workup.
Autoimmune hypoglycemia is a rare cause of hypoglycemia, which can be diagnosed on high index of clinical suspicion and systematic evaluation.
A 71-year-old woman with severe right lower leg pain, edema and erythema was presented to the Emergency Department and was found to have an extensive deep vein thrombosis (DVT) confirmed by ultrasound. She underwent an extensive evaluation due to her prior history of malignancy and new hypercoagulable state, but no evidence of recurrent disease was detected. Further investigation revealed pernicious anemia (PA), confirmed by the presence of a macrocytic anemia (MCV=115.8fL/red cell, Hgb=9.0g/dL), decreased serum B12 levels (56pg/mL), with resultant increased methylmalonic acid (5303nmol/L) and hyperhomocysteinemia (131μmol/L), the presumed etiology of the DVT. The patient also suffered from autoimmune thyroid disease (AITD), and both antithyroglobulin and anti-intrinsic factor antibodies were detected. She responded briskly to anticoagulation with heparin and coumadin and treatment of PA with intramuscular vitamin B12 injections. Our case suggests that a DVT secondary to hyperhomocystenemia may represent the first sign of polyglandular autoimmune syndrome III-B (PAS III-B), defined as the coexistent autoimmune conditions AITD and PA. It is important to recognize this clinical entity, as patients may not only require acute treatment with vitamin B12 supplementation and prolonged anticoagulation, as in this patient, but may also harbor other autoimmune diseases.
A DVT can be the first physical manifestation of a polyglandular autoimmune syndrome.
Hyperhomocysteinemia secondary to pernicious anemia should be considered as an etiology of an unprovoked DVT in a euthyroid patient with autoimmune thyroid disease.
Patients with DVT secondary to hyperhomocysteinemia should undergo screening for the presence of co-existent autoimmune diseases in addition to treatment with B12 supplementation and anticoagulation to prevent recurrent thromboembolism.