Safety and efficacy of low-dose PI3K inhibitor taselisib in adult patients with CLOVES and Klippel-Trenaunay syndrome (KTS): the TOTEM trial, a phase 1/2 multicenter, open-label, single-arm study.

PURPOSE: PIK3CA pathogenic variants in the PIK3CA-related overgrowth spectrum (PROS) activate phosphoinositide 3-kinase signaling, providing a rationale for targeted therapy, but no drug has proven efficacy and safety in this population. Our aim was to establish the six-month tolerability and efficacy of low-dose taselisib, a selective class I PI3K inhibitor, in PROS patients. METHODS: Patients over 16 years with PROS and PIK3CA pathogenic variants were included in a phase IB/IIA multicenter, open-label single-arm trial (six patients at 1 mg/day of taselisib, then 24 at 2 mg/day). The primary outcome was the occurrence of dose limiting toxicity (DLT). Efficacy outcomes were the relative changes after treatment of (1) tissue volume at affected and unaffected sites, both clinically and on imaging; (2) cutaneous vascular outcomes when relevant; (3) biologic parameters; (4) quality of life; and (5) patient-reported outcomes. RESULTS: Among 19 enrolled patients, 2 experienced a DLT (enteritis and pachymeningitis) leading to early trial termination (17 treated, 10 completed the study). No serious adverse reaction occurred in the 1 mg cohort (n = 6). No significant reduction in affected tissue volume was observed (mean -4.2%; p = 0.81; SD 14.01). Thirteen (76.4%) participants reported clinical improvement (pain reduction, chronic bleeding resolution, functional improvement). CONCLUSION: Despite functional improvement, the safety profile of low-dose taselisib precludes its long-term use.

Atypical neurofibromatosis type 1 with unilateral limb hypertrophy mimicking overgrowth syndrome.

Neurofibromatosis type 1 (NF1; OMIM 162200), a dominantly inherited multitumor syndrome, results from mutations in the Neurofibromin 1 (NF1) gene. We present the case of a Hungarian woman with the clinical phenotype of NF1 over her whole body and the clinical features of unilateral overgrowth involving her entire left leg. This unusual phenotype suggested either the atypical form of NF1 or the coexistence of NF1 and overgrowth syndrome. Direct sequencing of the genomic DNA isolated from peripheral blood revealed a novel frameshift mutation (c.5727insT, p.V1909fsX1912) in the NF1 gene. Next-generation sequencing of 50 oncogenes and tumour suppressor genes, performed on the genomic DNAs isolated from tissue samples and peripheral blood, detected only wild-type sequences. Based on these results, we concluded that the patient is affected by an unusual phenotype of NF1, and that the observed unilateral overgrowth of the left leg might be a rare consequence of the identified c.5727insT mutation.

EJE PRIZE 2015: How does insulin resistance arise, and how does it cause disease? Human genetic lessons.

Insulin orchestrates physiological responses to ingested nutrients; however, although it elicits widely ramifying metabolic and trophic responses from diverse tissues, 'insulin resistance (IR)', a pandemic metabolic derangement commonly associated with obesity, is usually defined solely by blunting of insulin's hypoglycaemic effect. Recent study of monogenic forms of IR has established that biochemical subphenotypes of IR exist, clustering into those caused by primary disorders of adipose tissue and those caused by primary defects in proximal insulin signalling. IR is often first recognised by virtue of its associated disorders including type 2 diabetes, dyslipidaemia (DL), fatty liver and polycystic ovary syndrome (PCOS). Although these clinically observed associations are confirmed by cross-sectional and longitudinal population-based studies, causal relationships among these phenomena have been more difficult to establish. Single gene IR is important to recognise in order to optimise clinical management and also permits testing of causal relationships among components of the IR syndrome using the principle of Mendelian randomisation. Thus, where a precisely defined genetic defect is identified that directly produces one component of the syndrome, then phenomena that are causally linked to that component should be seen. Where this is not the case, then a simple causal link is refuted. This article summarises known forms of monogenic severe IR and considers the lessons to be learned about the pathogenic mechanisms both upstream from common IR and those downstream linking it to disorders such as DL, fatty liver, PCOS and cancer.

Successful rhIGF1 treatment for over 5 years in a patient with severe insulin resistance due to homozygous insulin receptor mutation.

BACKGROUND: Congenital insulin resistance syndromes are caused by biallelic mutations within the insulin receptor gene (INSR). Recombinant human insulin-like growth factor (rhIGF1) has been used with mixed success; however, rigorous assessment of its efficacy is lacking. Here, we describe a child with a homozygous mutation in INSR successfully treated with rhIGF1 for more than 5 years. CASE REPORT: The patient presented with osmotic diabetes symptoms and was noted to have dysplastic dentition, hypertrichosis, coarse and dysmorphic facial features. Acanthosis nigricans, skin tags and rugated hyperkeratosis were also evident on the posterior neck, axilla and groin. A homozygous INSR essential splice site mutation (c.1268 + 2T > C, p.G374 fs*12) was identified, for which both parents were found to be heterozygous. The patient was treated with twice daily injections of rhIGF1 and metformin for more than 5 years with improvement in her acanthosis nigricans, hyperkeratosis and hypertrichosis. A dramatic fall in fasting insulin, HOMA-IR and HbA1c has been maintained over the entire course of treatment without adverse effects. Her linear growth velocity has remained on target for her predicted adult height. DISCUSSION: Our case demonstrates the effectiveness of rhIGF1 as an early treatment in a patient with a biallelic mutation within INSR without evidence of fluid retention, retinopathy, muscle pain, heart failure, cerebral infarcts or benign intracranial hypertension. Her case suggests rhIGF1 can and should be considered as an initial treatment option instead of as a final option in those with INSR mutations.

Growth and hormone profiling in children with congenital melanocytic naevi.

BACKGROUND: Multiple congenital melanocytic naevi (CMN) is a rare mosaic RASopathy, caused by postzygotic activating mutations in NRAS. Growth and hormonal disturbances are described in germline RASopathies, but growth and hormone status have not previously been investigated in individuals with CMN. OBJECTIVES: To explore premature thelarche, undescended testes, and a clinically abnormal fat distribution with CMN through prospective endocrinological assessment of a cohort of subjects with CMN, and a retrospective review of longitudinal growth of a larger group of patients with CMN from outpatient clinics (which included all subjects in the endocrinological assessment group). PATIENTS AND METHODS: Longitudinal growth in a cohort of 202 patients with single or multiple CMN was compared with the U.K. National Child Measurement Programme 2010. Forty-seven children had hormonal profiling including measurement of circulating luteinizing hormone, follicle-stimulating hormone, thyroid stimulating hormone, adrenocorticotrophic hormone, growth hormone, prolactin, pro-opiomelanocortin, estradiol, testosterone, cortisol, thyroxine, insulin-like growth factor-1 and leptin; 10 had oral glucose tolerance testing 25 had dual-energy X-ray absorptiometry scans for body composition. RESULTS: Body mass index increased markedly with age (coefficient 0·119, SE 0·016 standard deviation scores per year), at twice the rate of the U.K. population, due to increased adiposity. Three per cent of girls had premature thelarche variant and 6% of boys had persistent undescended testes. Both fat and muscle mass were reduced in areas underlying large naevi, resulting in limb asymmetry and abnormal truncal fat distribution. Anterior pituitary hormone profiling revealed subtle and variable abnormalities. Oral glucose tolerance tests revealed moderate-severe insulin insensitivity in five of 10, and impaired glucose tolerance in one. CONCLUSIONS: Interpersonal variation may reflect the mosaic nature of this disease and patients should be considered individually. Postnatal weight gain is potentially related to the underlying genetic defect; however, environmental reasons cannot be excluded. Naevus-related reduction of fat and muscle mass suggests local hormonal or metabolic effects on development or growth of adjacent tissues, or mosaic involvement of these tissues at the genetic level. Premature thelarche and undescended testes should be looked for, and investigated, as for any child.

Novel mutation in insulin receptor gene identified after muscle biopsy in a Niuean woman with severe insulin resistance.

BACKGROUND: Severe, early-onset insulin resistance in the absence of obesity, hepatic steatosis and dyslipidaemia is frequently attributable to a genetic defect affecting the insulin receptor. We describe a patient with severe insulin resistance in whom insulin receptor mutation analysis was mistakenly recorded as normal. Western blot analysis of skeletal muscle showed reduced insulin receptor protein and led to re-evaluation of the insulin receptor and the discovery of a novel mutation. CASE REPORT: A Niuean women, first evaluated at age 6 years for severe acanthosis nigricans, hirsutism, poor growth and cognitive impairment, had extremely elevated fasting insulin levels of 10740 IU/l (fasting reference range 4-24 IU/l) and a normal glucose concentration (4.9 mmol/l). Diabetes was diagnosed at age 9 years and metformin treatment introduced. By age 14 years, she developed refractory hyperglycaemia despite metformin, rosiglitazone and 240 IU insulin daily. Insulin receptor genetic analysis was documented as normal. At age 23 years, with a blood glucose concentration of 37 mmol/l and an HbA1c concentration of 116 mmol/mol, U500 insulin 2000 IU/day was required for glycaemic control. She developed severe proliferative diabetic retinopathy with neovascular glaucoma leading to blindness. There was no renal dysfunction, dyslipidaemia or hepatic steatosis. A muscle biopsy was performed to evaluate the insulin signalling pathway and showed reduced insulin receptor protein. Sequencing of the insulin receptor showed a homozygous p.Val1010Leu missense mutation. CONCLUSION: This patient illustrates the use of muscle biopsy in the evaluation of a patient with unexplained severe insulin resistance. This approach may usefully be applied to other cases of severe insulin resistance, where genetic testing for known mutations in the insulin signalling pathway has been negative.

Analytical and clinical challenges in a patient with concurrent type 1 diabetes, subcutaneous insulin resistance and insulin autoimmune syndrome.

UNLABELLED: A lean 15-year-old girl was diagnosed with type 1 diabetes based on symptomatic hyperglycaemia and positive anti-islet cell antibodies. Glycaemia was initially stabilised on twice-daily mixed insulin. After 11 months from the time of diagnosis, she complained of hyperglycaemia and ketosis alternating with hypoglycaemia. This progressively worsened until prolonged hospital admission was required for treatment of refractory hypoglycaemia. A high titre of anti-insulin antibodies was detected associated with a very low recovery of immunoreactive (free) insulin from plasma after precipitation with polyethylene glycol, suggesting the presence of insulin in bound complexes. Insulin autoimmune syndrome was diagnosed and metabolic fluctuations were initially managed supportively. However, due to poor glucose control, immunosuppressive therapy was initiated first with steroids and plasmapheresis and later with anti-CD20 antibody therapy (Rituximab). This treatment was associated with a gradual disappearance of anti-insulin antibodies and her underlying type 1 diabetes has subsequently been successfully managed with an insulin pump. LEARNING POINTS: Anti-insulin antibodies may result in low levels of free insulin.Polyclonal anti-insulin antibodies can interfere with the pharmacological action of administered insulin, resulting in hypoglycaemia and insulin resistance, due to varying affinities and capacities.In this patient, rituximab administration was associated with a gradual disappearance of anti-insulin antibodies.It is hypothesised that this patient had subcutaneous insulin resistance (SIR) caused by insulin capture at the tissue level, either by antibodies or by sequestration.A prolonged tissue resistance protocol may be more appropriate in patients with immune-mediated SIR syndrome.

Identification and Characterisation of a Novel Pathogenic Mutation in the Human Lipodystrophy Gene AGPAT2 : C48R: A Novel Mutation in AGPAT2.

Loss-of-function mutations in AGPAT2, encoding 1-acylglycerol-3-phosphate-O-acyltransferase 2 (AGPAT2), produce congenital generalised lipodystrophy (CGL). We screened the AGPAT2 gene in two siblings who presented with pseudoacromegaly, diabetes and severe dyslipidaemia and identified a novel mutation in AGPAT2 causing a single amino acid substitution, p.Cys48Arg. We subsequently investigated the molecular pathogenic mechanism linking both this mutation and the previously reported p.Leu228Pro mutation to clinical disease. Wild-type and mutant AGPAT2 were expressed in control and AGPAT2-deficient preadipocyte cell lines. mRNA and protein expression was determined, and the ability of each AGPAT2 species to rescue adipocyte differentiation in AGPAT2-deficient cells was assessed. Protein levels of both p.Cys48Arg and p.Leu228Pro AGPAT2 were significantly reduced compared with that of wild-type AGPAT2 despite equivalent mRNA levels. Stable expression of wild-type AGPAT2 partially rescued adipogenesis in AGPAT2 deficient preadipocytes, whereas stable expression of p.Cys48Arg or p.Leu228Pro AGPAT2 did not. In conclusion, unusually severe dyslipidaemia and pseudoacromegaloid overgrowth in patients with diabetes should alert physicians to the possibility of lipodystrophy. Both the previously unreported pathogenic p.Cys48Arg mutation in AGPAT2, and the known p.Leu228Pro mutation result in decreased AGPAT2 protein expression in developing adipocytes. It is most likely that the CGL seen in homozygous carriers of these mutations is largely accounted for by loss of protein expression.

Adiponectin and leptin in human severe insulin resistance - diagnostic utility and biological insights.

There is an intimate interplay between systemic insulin action and the actions of the adipocyte-derived proteins leptin and adiponectin. Concordant findings in humans and rodents demonstrate that leptin gates critical physiological functions to the prevailing nutritional state, however the physiological functions of adiponectin are less convincingly established. Murine evidence suggests that adiponectin can exert insulin-sensitising effects, plasma concentrations of adiponectin in humans correlate in most populations with insulin sensitivity, and increasingly strong evidence suggests an association between common genetic variation around the adiponectin gene and diabetes. However rare and severe genetic variants lowering adiponectin levels have not been convincingly associated with insulin resistance, and the discordant and sometimes extreme hyperadiponectinaemia seen in patients with severe insulin resistance due to loss of insulin receptor function poses a challenge to the widely held view that low adiponectin in humans plays a role in causing prevalent insulin resistance. The mechanism underlying this phenomenon remains to be elucidated, but the best available evidence implicates increased production of adiponectin in states of insulin receptor dysfunction, attributable at least in part to increased transcription of the ADIPOQ gene. Further investigation of the cellular basis of insulin receptoropathy-related hyperadiponectinaemia may shine further light on the human pathobiology of this most abundant and enigmatic product of adipose tissue.

An activating mutation of AKT2 and human hypoglycemia.

Pathological fasting hypoglycemia in humans is usually explained by excessive circulating insulin or insulin-like molecules or by inborn errors of metabolism impairing liver glucose production. We studied three unrelated children with unexplained, recurrent, and severe fasting hypoglycemia and asymmetrical growth. All were found to carry the same de novo mutation, p.Glu17Lys, in the serine/threonine kinase AKT2, in two cases as heterozygotes and in one case in mosaic form. In heterologous cells, the mutant AKT2 was constitutively recruited to the plasma membrane, leading to insulin-independent activation of downstream signaling. Thus, systemic metabolic disease can result from constitutive, cell-autonomous activation of signaling pathways normally controlled by insulin.

Mechanistic insights into insulin resistance in the genetic era.

Sir Harold Himsworth first observed and articulated the phenomenon of insulin resistance in the late 1930s. Although a long delay followed before his observations were acknowledged and enshrined in formal diagnostic classifications of diabetes mellitus, insulin resistance-related pathology in the early 21st century poses one of the major global healthcare challenges for contemporary physicians. Whilst insulin resistance is closely related to obesity and decreased physical fitness, despite intensive investigation it has proved extremely challenging to discriminate key events in its causation from epiphenomena, many related to compensation for the primary defect. Thus, a complete account of the molecular pathogenesis of insulin resistance-related diseases remains elusive. One approach circumventing such problems is the study of patients with single gene defects causing severe insulin resistance. In such patients the primary defect is known, and thus lessons may be learned about human physiology from detailed physiological study allied to knowledge of the function of the mutated protein. This review discusses developments in understanding of monogenic severe insulin resistance since discovery of the first insulin receptor mutations in 1988 and reviews the physiological lessons learnt, including the critical role of adipose tissue in human metabolic health and the meaning and importance of 'partial' insulin resistance for major human disease.

Founder effect in the Horn of Africa for an insulin receptor mutation that may impair receptor recycling.

AIMS/HYPOTHESIS: Genetic insulin receptoropathies are a rare cause of severe insulin resistance. We identified the Ile119Met missense mutation in the insulin receptor INSR gene, previously reported in a Yemeni kindred, in four unrelated patients with Somali ancestry. We aimed to investigate a possible genetic founder effect, and to study the mechanism of loss of function of the mutant receptor. METHODS: Biochemical profiling and DNA haplotype analysis of affected patients were performed. Insulin receptor expression in lymphoblastoid cells from a homozygous p.Ile119Met INSR patient, and in cells heterologously expressing the mutant receptor, was examined. Insulin binding, insulin-stimulated receptor autophosphorylation, and cooperativity and pH dependency of insulin dissociation were also assessed. RESULTS: All patients had biochemical profiles pathognomonic of insulin receptoropathy, while haplotype analysis revealed the putative shared region around the INSR mutant to be no larger than 28 kb. An increased insulin proreceptor to ß subunit ratio was seen in patient-derived cells. Steady state insulin binding and insulin-stimulated autophosphorylation of the mutant receptor was normal; however it exhibited decreased insulin dissociation rates with preserved cooperativity, a difference accentuated at low pH. CONCLUSIONS/INTERPRETATION: The p.Ile119Met INSR appears to have arisen around the Horn of Africa, and should be sought first in severely insulin resistant patients with ancestry from this region. Despite collectively compelling genetic, clinical and biochemical evidence for its pathogenicity, loss of function in conventional in vitro assays is subtle, suggesting mildly impaired receptor recycling only.

Loss of NPC1 function in a patient with a co-inherited novel insulin receptor mutation does not grossly modify the severity of the associated insulin resistance.

In Npc1 null mice, a model for Niemann Pick Disease Type C1, it has been reported that hepatocyte insulin receptor function is significantly impaired, consistent with growing evidence that membrane fluidity and microdomain structure have an important role in insulin signal transduction. However, whether insulin receptor function is also compromised in human Niemann Pick disease Type C1 is unclear. We now report a girl who developed progressive dementia, ataxia and opthalmoplegia from 9 years old, followed by severe acanthosis nigricans, hirsutism and acne at 11 years old. She was diagnosed with Niemann Pick Disease type C1 (OMIM#257220) based on positive filipin staining and reduced cholesterol-esterifying activity in dermal fibroblasts, and homozygosity for the p.Ile1061Thr NPC1 mutation. Further analysis revealed her also to be heterozygous for a novel trinucleotide deletion (c.3659 + 1_3659 + 3delGTG) at the end of exon 20 of INSR, encoding the insulin receptor, leading to deletion of Trp1193 in the intracellular tyrosine kinase domain. INSR mRNA and protein levels were normal in dermal fibroblasts, consistent with a primary signal transduction defect in the mutant receptor. Although the proband was significantly more insulin resistant than her father, who carried the INSR mutation but was only heterozygous for the NPC1 variant, their respective degrees of IR were very similar to those previously reported in a father-daughter pair with the closely related p.Trp1193Leu INSR mutation. This suggests that loss of NPC1 function, with attendant changes in membrane cholesterol composition, does not significantly modify the IR phenotype, even in the context of severely impaired INSR function.

Knockdown of the Alström syndrome-associated gene Alms1 in 3T3-L1 preadipocytes impairs adipogenesis but has no effect on cell-autonomous insulin action.

Alström syndrome is a rare genetic syndrome associated with early-onset obesity, severe insulin resistance (IR) that is disproportionate to the degree of adiposity and premature diabetes. The ALMS1 gene, which is mutated in Alström syndrome, encodes a giant 460 kDa centrosome- and basal body-associated protein. Its function is unknown, although roles in primary cilia formation and function, intracellular organelle trafficking and, most recently, adipocyte differentiation have been mooted. We now test the hypothesis that the severe IR and dyslipidaemia in Alström syndrome are accounted for by a partial defect in adipogenesis and/or insulin action in mature adipocytes, leading to relative failure of adipose tissue to discharge its role in metabolic homeostasis. Stable knockdown of Alms1 expression by >80% in 3T3-L1 preadipocytes was associated with impairment of lipid accumulation and at least a twofold reduction in adipocyte gene expression following hormonal induction of adipogenesis. This was accompanied by a commensurate defect in insulin-stimulated glucose uptake. Proximal signalling events in response to insulin were unaffected. These results suggest that partial impairment of adipogenesis in Alström syndrome may contribute to the severity of the associated metabolic phenotype, whereas the ability of insulin to stimulate glucose uptake into adipocytes is grossly unimpaired.

Treatment of type B insulin resistance: a novel approach to reduce insulin receptor autoantibodies.

BACKGROUND: Type B insulin resistance belongs to a class of diseases caused by an autoantibody to a cell surface receptor. Blockade of insulin action results in hyperglycemia, hypercatabolism, severe acanthosis nigricans, and hyperandrogenism in women. This rare autoimmune disorder has been treated with various forms of immunosuppression with mixed success. METHODS: We describe 14 patients with type B insulin resistance referred to the National Institutes of Health, adding to an existing cohort of 24 patients. This report focuses on seven patients who were treated with an intensive combination protocol of rituximab, cyclophosphamide, and pulse corticosteroids aimed at control of pathogenic autoantibody production. Hematological, metabolic, and endocrine parameters, including fasting glucose, glycated hemoglobin, insulin dose, lipids, and testosterone, were monitored before and after treatment. RESULTS: All seven treated patients achieved remission, defined as amelioration of hyperglycemia, discontinuation of insulin therapy, and resolution of hyperandrogenism. Glycated hemoglobin has normalized in all seven treated patients. Remission was achieved on average in 8 months from initiation of treatment. The medication regimen was well tolerated, with no serious adverse events. CONCLUSIONS: In seven patients with type B insulin resistance, standardized treatment with rituximab, cyclophosphamide, and pulse steroids results in remission of the disease. Future studies will determine whether this treatment protocol can be applied to other autoantibody/cell surface receptor disease states.

The effects of neurokinin B upon gonadotrophin release in male rodents.

Growing evidence suggests the tachykinin neurokinin B (NKB) may modulate gonadotrophin secretion and play a role in sex-steroid feedback within the reproductive axis. NKB signalling has recently been identified as being necessary for normal human reproductive function, although the precise mechanisms underpinning this role remain to be established. We have used rodents to explore further the role of NKB within the reproductive axis. In particular, we have studied its interactions with kisspeptin, a neuropeptide essential for reproductive function in rodent and human with close anatomical links to NKB within the hypothalamus. Intraperitoneal administration of NKB (50 nmol) to male mice had no effect on circulating luteinsing hormone (LH) levels and, although i.p. kisspeptin (15 nmol) increased LH five-fold, co-administration of NKB and kisspeptin was indistinguishable from kisspeptin alone. Intracerebroventricular administration of NKB (10 nmol) to male mice also had no effect on LH levels, with 1 nmol kisspeptin i.c.v. significantly increasing LH compared to control (0.37 +/- 0.18 versus 5.11 +/- 0.28 ng/ml, respectively). Interestingly, i.c.v. co-administration of NKB and kisspeptin caused a significant increase in LH concentrations compared to kisspeptin alone (8.96 +/- 1.82 versus 5.11 +/- 0.28 ng/ml respectively). We used hypothalamic explants from rats to assess the effect of NKB on gonadotrpohin-releasing hormone (GnRH) secretion ex vivo. Doses of NKB up to 1000 nm failed to stimulate GnRH secretion, whereas 100 nm kisspeptin robustly increased GnRH secretion. Of note, co-administration of NKB with kisspeptin abrogated the effect of kisspeptin, producing no GnRH release above basal state. Finally, we analysed the expression of Tac2/Tacr3 (genes encoding NKB and NK3R, respectively) within the arcuate nucleus in different nutritional states. After a 48-h fast, the expression of both Tac2 and Tacr3 showed a significant increase, in contrast to levels of Kiss1 and Kiss1r mRNA, which remained unchanged. In male rodent models, NKB and kisspeptin have different effects upon gonadotrophin release and appear to interact in a complex manner.

Severe insulin resistance due to anti-insulin antibodies: response to plasma exchange and immunosuppressive therapy.

Anti-insulin antibodies have been described in two contexts: in insulin-naive individuals (so-called 'insulin autoimmune syndrome') and in patients with insulin-treated diabetes, in whom antibodies are rarely of clinical significance. We report the case of an 68-year-old woman who exhibited a local allergic reaction to subcutaneous insulin followed by severe insulin resistance, evidenced by poor glycaemic control despite treatment with > 3.5 U/kg of insulin per day. She was found to have circulating polyclonal anti-insulin antibodies of the IgG subtype and responded clinically to a course of plasma exchange and immunosuppression with mycophenolate mofetil and, subsequently, intravenous immunoglobulin. Falling titres of antibodies on this regimen correlated with improved glycaemic control. This case suggests that clinicians should be alert to the possibility of insulin resistance due to anti-insulin antibodies and that immunosuppression in this situation may be a valuable therapeutic option.