Spurious HbA1c results in patients with diabetes treated with dapsone

SUMMARY

Measurement of glycated haemoglobin (HbA1c) has been utilised in assessing long-term control of blood glucose in patients with diabetes, as well as diagnosing diabetes and identifying patients at increased risk of developing diabetes in the future. HbA1c reflects the level of blood glucose to which the erythrocyte has been exposed during its lifespan, and there are a number of clinical situations affecting the erythrocyte life span in which HbA1c values may be spuriously high or low and therefore not reflective of the true level of glucose control. In the present case series, we describe the particulars of three patients with diabetes who had spuriously low HbA1c levels as a result of dapsone usage. Furthermore, we discuss the limitations of HbA1c testing and the mechanisms by which it may be affected by dapsone in particular.

LEARNING POINTS

Various conditions and medications can result in falsely low HbA1c. Dapsone can lead to falsely low HbA1c by inducing haemolysis and by forming methaemoglobin. Capillary glucose measurement, urine glucose measurements and fructosamine levels should be used as alternatives to HbA1c for monitoring glycaemic control if it was falsely low or high.

Fulminant hepatitis and elevated levels of sIL-2R in thyroid storm

SUMMARY

We report the case of a 48-year-old man with thyroid storm associated with fulminant hepatitis and elevated levels of soluble interleukin-2 receptor (sIL-2R). Fatigue, low-grade fever, shortness of breath, and weight loss developed over several months. The patient was admitted to the hospital because of tachycardia-induced heart failure and liver dysfunction. Graves' disease with heart failure was diagnosed. He was treated with methimazole, inorganic iodide, and a β-blocker. On the day after admission, he became unconscious with a high fever and was transferred to the intensive care unit. Cardiogenic shock with atrial flutter was treated with intra-aortic balloon pumping and cardioversion. Hyperthyroidism decreased over 10 days, but hepatic failure developed. He was diagnosed with thyroid storm accompanied by fulminant hepatitis. Laboratory investigations revealed elevated levels of sIL-2R (9770 U/mL). The fulminant hepatitis was refractory to plasma exchange and plasma filtration with dialysis, and no donors for liver transplantation were available. He died of hemoperitoneum and gastrointestinal hemorrhage due to fulminant hepatitis 62 days after admission. Elevated circulating levels of sIL-2R might be a marker of poor prognosis in thyroid storm with fulminant hepatitis.

LEARNING POINTS

The prognosis of thyroid storm when fulminant hepatitis occurs is poor. Liver transplantation is the preferred treatment for fulminant hepatitis induced by thyroid storm refractory to plasma exchange. Elevated levels of soluble interleukin-2 receptor might be a marker of poor prognosis in patients with thyroid storm.

Prolonged acidosis is a feature of SGLT2i-induced euglycaemic diabetic ketoacidosis

SUMMARY

We describe two cases of SGLT2i-induced euglycaemic diabetic ketoacidosis, which took longer than we anticipated to treat despite initiation of our DKA protocol. Both patients had an unequivocal diagnosis of type 2 diabetes, had poor glycaemic control with a history of metformin intolerance and presented with relatively vague symptoms post-operatively. Neither patient had stopped their SGLT2i pre-operatively, but ought to have by current treatment guidelines.

LEARNING POINTS

SGLT2i-induced EDKA is a more protracted and prolonged metabolic derangement and takes approximately twice as long to treat as hyperglycaemic ketoacidosis. Surgical patients ought to stop SGLT2i medications routinely pre-operatively and only resume them after they have made a full recovery from the operation. While the mechanistic basis for EDKA remains unclear, our observation of marked ketonuria in both patients suggests that impaired ketone excretion may not be the predominant metabolic lesion in every case. Measurement of insulin, C-Peptide, blood and urine ketones as well as glucagon and renal function at the time of initial presentation with EDKA may help to establish why this problem occurs in specific patients.

A sarcoidosis-lymphoma syndrome revealed by hypopituitarism

SUMMARY

A 26-year-old woman presented with persistent headache and tiredness. Biological investigations disclosed a moderate inflammatory syndrome, low PTH-hypercalcemia and complete anterior hypopituitarism. A magnetic resonance imaging (MRI) of the pituitary gland was performed and revealed a symmetric enlargement with a heterogeneous signal. Ophthalmological examination showed an asymptomatic bilateral anterior and posterior uveitis, and a diagnosis of pituitary sarcoidosis was suspected. As the localization of lymphadenopathies on the fused whole-body FDG-PET/computerized tomography (CT) was not evoking a sarcoidosis in first instance, an excisional biopsy of a left supraclavicular adenopathy was performed showing classic nodular sclerosis Hodgkin's lymphoma (HL). A diagnostic transsphenoidal biopsy of the pituitary gland was proposed for accurate staging of the HL and surprisingly revealed typical granulomatous inflammation secondary to sarcoidosis, leading to the diagnosis of a sarcoidosis-lymphoma syndrome. The co-existence of these diseases constitutes a diagnostic challenge and we emphasize the necessity of exact staging of disease in order to prescribe adequate treatment.

LEARNING POINTS

The possibility of a sarcoidosis-lymphoma syndrome, although rare, should be kept in mind during evaluation for lymphadenopathies. In the case of such association, lymphoma usually occurs after sarcoidosis. However, sarcoidosis and lymphoma can be detected simultaneously and development of sarcoidosis in a patient with previous lymphoma has also been reported. An accurate diagnosis of the disease and the respective organ involvements, including biopsy, is necessary in order to prescribe adequate treatment.

POEMS syndrome: a rare cause of adrenal insufficiency in a young male

SUMMARY

POEMS syndrome (Polyneuropathy, Organomegaly, Endocrinopathy, Monoclonal protein and Skin changes) is a rare multisystemic disease. Clinical presentation is variable, the only mandatory criteria being polyneuropathy and monoclonal gammapathy in association with one major and one minor criterion. Primary adrenal insufficiency is rarely reported. We describe a case of a 33-year-old patient, in whom the presenting symptoms were mandibular mass, chronic sensory-motor peripheral polyneuropathy and adrenal insufficiency. The laboratory evaluation revealed thrombocytosis, severe hyperkalemia with normal renal function, normal protein electrophoresis and negative serum immunofixation for monoclonal protein. Endocrinologic laboratory work-up confirmed Addison's disease and revealed subclinical primary hypothyroidism. Thoracic abdominal CT showed hepatosplenomegaly, multiple sclerotic lesions in thoracic vertebra and ribs. The histopathologic examination of the mandibular mass was nondiagnostic. Bone marrow biopsy revealed plasma cell dyscrasia and confirmed POEMS syndrome. Axillary lymphadenopathy biopsy: Castleman's disease. Gluco-mineralocorticoid substitution and levothyroxine therapy were started with clinical improvement. Autologous hematopoietic cell transplantation (HCT) was planned, cyclophosphamide induction was started. Meanwhile the patient suffered two ischemic strokes which resulted in aphasia and hemiparesis. Cerebral angiography revealed vascular lesions compatible with vasculitis and stenosis of two cerebral arteries. The patient deceased 14 months after the diagnosis. The young age at presentation, multiplicity of manifestations and difficulties in investigation along with the absence of serum monoclonal protein made the diagnosis challenging. We report this case to highlight the need to consider POEMS syndrome in differential diagnosis of peripheral neuropathy in association with endocrine abnormalities even in young patients.

LEARNING POINTS

POEMS syndrome is considered a 'low tumor burden disease' and the monoclonal protein in 15% of cases is not found by immunofixation. Neuropathy is the dominant characteristic of POEMS syndrome and it is peripheral, ascending, symmetric and affecting both sensation and motor function. Endocrinopathies are a frequent feature of POEMS syndrome, but the cause is unknown. The most common endocrinopathies are hypogonadism, primary hypothyroidism and abnormalities in glucose metabolism. There is no standard therapy; however, patients with disseminated bone marrow involvement are treated with chemotherapy with or without HCT.

Clinical challenges of a co-secreting TSH/GH pituitary adenoma

SUMMARY

Co-secreting thyrotropin/growth hormone (GH) pituitary adenomas are rare; their clinical presentation and long-term management are challenging. There is also a paucity of long-term data. Due to the cell of origin, these can behave as aggressive tumours. We report a case of a pituitary plurihormonal pit-1-derived macroadenoma, with overt clinical hyperthyroidism and minimal GH excess symptoms. The diagnosis was confirmed by pathology showing elevated thyroid and GH axes with failure of physiological GH suppression, elevated pituitary glycoprotein hormone alpha subunit (αGSU) and macroadenoma on imaging. Pre-operatively the patient was rendered euthyroid with carbimazole and underwent successful transphenoidal adenomectomy (TSA) with surgical cure. Histopathology displayed an elevated Ki-67 of 5.2%, necessitating long-term follow-up.

LEARNING POINTS

Thyrotropinomas are rare and likely under-diagnosed due to under-recognition of secondary hyperthyroidism. Thyrotropinomas and other plurihormonal pit-1-derived adenomas are more aggressive adenomas according to WHO guidelines. Co-secretion occurs in 30% of thyrotropinomas, requiring diligent investigation and long-term follow-up of complications.

Etomidate in the management of severe Cushing's disease and MRSA bacteraemia in a district general hospital in the United Kingdom

SUMMARY

We report our experience on managing a case of florid Cushing's disease with Methicillin-resistant Staphylococcus aureus (MRSA) sepsis using intravenous etomidate in the intensive care unit of a UK district general hospital.

LEARNING POINTS

Severe Cushing's syndrome is associated with high morbidity and mortality. Etomidate is a safe and effective medical therapy to rapidly lower cortisol levels even in the context of severe sepsis and immunosuppression. Etomidate should ideally be administered in an intensive care unit but is still feasible in a district general hospital. During treatment with etomidate, accumulation of serum 11β-deoxycortisol (11DOC) levels can cross-react with laboratory cortisol measurement leading to falsely elevated serum cortisol levels. For this reason, serum cortisol measurement using a mass spectrometry assay should ideally be used to guide etomidate prescription.

Restoration of fertility in a woman with giant prolactinoma in response to cabergoline treatment

SUMMARY

A 32-year-old woman presented with primary amenorrhoea, prolactin (PRL) level of 154 150 mIU/L and was diagnosed with a giant pituitary adenoma measuring maximum 6.2 cm. Cabergoline (CAB) treatment at a dose of 0.5 mg/week was prescribed to the patient. The treatment decreased the tumour size after 3 months (MRI scans of the brain) and brought back to normal the level of the PRL (345 mIU/L) after 6 months of CAB treatment. After 7 months of CAB treatment, menarche was achieved, and after 12 months, the patient became pregnant. She discontinued taking CAB at 4-week gestation. The pregnancy resulted in a missed miscarriage at 6-7 weeks; an abortion was conducted by the vacuum aspiration method. The MRI scans of the brain did not show any tumour enlargement. After 18 months from the start of the treatment the patient got pregnant for the second time. At 25-week gestation an MRI scan of the brain was conducted which did not show any increase in the tumour size. At 38 weeks the patient delivered a healthy full-term girl via C-section. The patient chose not to breastfeed and resumed CAB therapy after the delivery. During the treatment, the PRL level returned to the normal range and the menstrual cycle was restored. After 3 years the patient got pregnant for the third time. The patient did not receive CAB during the pregnancies; the examination did not show any tumour enlargement. Further MRI scans did not show any tumour growth. CAB therapy was effective in normalization of the PRL level, tumour shrinkage, menarche and pregnancy-induction which led to the birth of healthy children in a woman with primary amenorrhoea and a giant prolactinoma invading the skull base bones.

LEARNING POINTS

Giant prolactinomas are very rarely found in women. Cabergoline therapy can be effective in the normalization of the PRL level, tumour shrinkage, menarche induction in a woman with primary amenorrhoea, and giant prolactinoma. Cabergoline therapy can be effective in pregnancy induction which leads to the birth of children in a woman with giant prolactinoma. Cabergoline discontinuation did not trigger tumour enlargement during pregnancy.

Kallmann syndrome and ichthyosis: a case of contiguous gene deletion syndrome

Kallmann syndrome is a genetically heterogeneous form of hypogonadotropic hypogonadism caused by gonadotropin-releasing hormone deficiency and characterized by anosmia or hyposmia due to hypoplasia of the olfactory bulbs; osteoporosis and metabolic syndrome can develop due to longstanding untreated hypogonadism. Kallmann syndrome affects 1 in 10 000 men and 1 in 50 000 women. Defects in 17 genes, including KAL1, have been implicated. Kallmann syndrome can be associated with X-linked ichthyosis, a skin disorder characterized by early onset dark, dry, irregular scales affecting the limb and trunk, caused by a defect of the steroid sulfatase gene (STS). Both KAL1 and STS are located in the Xp22.3 region; therefore, deletions in this region cause a contiguous gene syndrome. We report the case of a 32-year-old man with ichthyosis referred for evaluation of excessive height (2.07 m) and weight (BMI: 29.6 kg/m2), microgenitalia and absence of secondary sex characteristics. We diagnosed Kallmann syndrome with ichthyosis due to a deletion in Xp22.3, a rare phenomenon. Learning points: Kallmann syndrome is a genetically heterogeneous disease characterized by hypogonadotropic hypogonadism with anosmia or hyposmia associated with defects in the production or action of gonadotropin-releasing hormone (GnRH) and hypoplasia of the olfactory bulbs. Several genes have been implicated in Kallmann syndrome, including KAL1, located in the Xp22.3 region, which is responsible for X-linked Kallmann syndrome. KAL1 encodes the protein anosmin-1. X-linked ichthyosis is caused by deficiency of the steroid sulfatase enzyme, encoded by STS, which is also located in the Xp22.3 region. Deletions involving this region can affect both genes and result in contiguous gene syndromes. Phenotype can guide clinicians toward suspicion of a specific genetic mutation. KAL1 mutations are mostly related to microgenitalia, unilateral renal agenesis and synkinesia, although patients need not present all these abnormalities. Longstanding untreated hypogonadism is associated with poor sexual health, osteoporosis and metabolic syndrome with the concomitant risk of developing type 2 diabetes mellitus and obesity. Treatment aims to promote the development of secondary sex characteristics, build and sustain normal bone and muscle mass and restore fertility. Treatment can also help minimize some psychological consequences. Treatments available for patients with congenital GnRH deficiency such as Kallmann syndrome include gonadal steroid hormones, human gonadotropins and GnRH. The choice of therapy depends on the goal or goals.