Recombinant Human Insulin-Like Growth Factor-1 Treatment of Severe Growth Failure in Three Siblings with STAT5B Deficiency.

INTRODUCTION: Patients with homozygous recessive mutations in STAT5B have severe progressive postnatal growth failure and insulin-like growth factor-I (IGF-I) deficiency associated with immunodeficiency and increased risk of autoimmune and pulmonary conditions. This report describes the efficacy and safety of recombinant human IGF-1 (rhIGF-1) in treating severe growth failure due to STAT5B deficiency. CASE PRESENTATION: Three siblings (P1, 4.4 year-old female; P2, 2.3 year-old male; and P3, 7 month-old female) with severe short stature (height SDS [HtSDS] -6.5, -4.9, -5.3, respectively) were referred to the Center for Growth Disorders at Cincinnati Children's Hospital Medical Center. All three had a homozygous mutation (p.Trp631*) in STAT5B. Baseline IGF-I was 14.7, 14.1, and 10.8 ng/mL, respectively (all < -2.5 SDS for age and sex), and IGFBP-3 was 796, 603, and 475 ng/mL, respectively (all < -3 SDS for age and sex). The siblings were started on rhIGF-1 at 40 µg/kg/dose twice daily subcutaneously (SQ), gradually increased to 110-120 µg/kg/dose SQ twice daily as tolerated. HtSDS and height velocity (HV) were monitored over time. RESULTS: Six years of growth data was utilized to quantify growth response in the two older siblings and 5 years of data in the youngest. Pre-treatment HVs were, respectively, 3.0 (P1), 3.0 (P2), and 5.2 (P3) cm/year. With rhIGF-1 therapy, HVs increased to 5.2-6.0, 4.8-7.1, and 5.5-7.4 cm/year, respectively, in the first 3 years of treatment, before they decreased to 4.7, 3.8, and 4.3 cm/year, respectively, at a COVID-19 pandemic delayed follow-up visit and with decreased treatment adherence. ΔHtSDS for P1 and P2 was +2.21 and +0.93, respectively, over 6 years, but -0.62 for P3 after 5 years and in the setting of severe local lipohypertrophy and suboptimal weight gain. P3 also experienced hypoglycemia that limited our ability to maintain target rhIGF-1 dosing. CONCLUSION: The response to rhIGF-1 therapy is less than observed with rhIGF-1 therapy for patients previously described with severe primary IGF-I deficiency, including patients with documented defects in the growth hormone receptor, but may still provide patients with STAT5B deficiency with an opportunity to prevent worsening growth failure.

The MiniMed 780G automated insulin delivery system adapts to substantial changes in daily routine: Lessons from real world users during Ramadan.

AIM: To report on the effectiveness and safety of the MiniMed 780G automated insulin delivery system in real-world users during the month of Ramadan. MATERIALS AND METHODS: CareLink Personal data were extracted from MiniMed 780G system users from the Gulf region. Users were included if they had ≥10 days of sensor glucose data during the month of Ramadan 2022 as well as in the month before and after. For the main analysis, continuous glucose monitoring endpoints were aggregated per month and were reported by time of day (daytime: 05.31-18.00 h, and night-time). Additional analyses were performed to study the pace at which the algorithm adapts. RESULTS: Glycaemic control was well kept in the 449 included users (mean sensor glucose = 152.6 ± 18.7 mg/dl, glucose management indicator = 7.0 ± 0.4%, time in range = 70.7 ± 11.0%, time below 70 mg/dl = 2.3 ± 2.3%). Albeit some metrics differed from the month before (p < .0001 for all), absolute differences were very small and considered clinically irrelevant. During Ramadan, there was no increased risk of hypoglycaemia during daytime (time below 70 mg/dl = 2.3 ± 2.4%), time in range was highest during daytime (80.0 ± 10.7%, night: 60.4 ± 15.3%), while time above 180 mg/dl was highest during night-time (37.3 ± 16.3%, day: 17.7 ± 10.7%). The algorithm adapted immediately upon lifestyle change. CONCLUSION: The MiniMed 780G automated insulin delivery system is effective, safe and fast in adapting to the substantial changes that occur in the lifestyle of people with type 1 diabetes during Ramadan.

Developmental Adaptive Immune Defects Associated with STAT5B Deficiency in Three Young Siblings.

Patients with rare homozygous mutations in signal transducer and activator of transcription 5B (STAT5B) develop immunodeficiency resulting in chronic eczema, chronic infections, autoimmunity, and chronic lung disease. STAT5B-deficient patients are typically diagnosed in the teenage years, limiting our understanding of the development of associated phenotypic immune abnormalities. We report the first detailed chronological account of post-natal immune dysfunction associated with STAT5B deficiency in humans. Annual immunophenotyping of three siblings carrying a novel homozygous nonsense mutation in STAT5B was carried out over 4 years between the ages of 7 months to 8 years. All three siblings demonstrated consistent B cell hyperactivity including elevated IgE levels and autoantibody production, associated with diagnoses of atopy and autoimmunity. Total T cell levels in each sibling remained normal, with regulatory T cells decreasing in the oldest sibling. Interestingly, a skewing toward memory T cells was identified, with the greatest changes in CD8+ effector memory T cells. These results suggest an importance of STAT5B in B cell function and naïve versus memory T cell survival. Progressive dysregulation of FOXP3+ regulatory T cells and CD8+ memory T cell subsets reveal a crucial role of STAT5B in T cell homeostasis. The early diagnosis and focused immune evaluations of these three young STAT5B-deficient siblings support an important role of STAT5B in adaptive immune development and function.

Attentiveness of pediatricians to primary immunodeficiency disorders.

BACKGROUND: Primary immunodeficiency (PID) is a cluster of serious disorders that requires special alertness on the part of the medical staff for prompt diagnosis and management of the patient. This study explored PID knowledge and experience among pediatricians of wide educational backgrounds, practicing in the United Arab Emirates (UAE). METHOD: A self-administered questionnaire was used to determine the competency of pediatricians in their knowledge of PID disorders. This study questionnaire included questions on PID signs and symptoms, syndromes associated with immunodeficiency, screening tests, interpreting laboratory tests and case management. The participants were 263 pediatricians of diverse education working in the 27 governmental hospitals in all regions of UAE. RESULTS: The overall performance of the pediatricians did not differ based on their age, gender, origin of certification, rank, or years of experience. Of the 50 questions, 20% of pediatricians answered correctly <60% of the questions, 76% answered correctly 60 to 79% of the questions, and 4% answered correctly ≥80% of the questions. Seventeen of the 19 PID signs and symptoms were identified by 55 to 97%. Four of 5 syndromes associated with immunodeficiency were identified by 50 to 90%. Appropriate screening tests were chosen by 64 to 96%. Attention to the laboratory reference range values as function of patient age was notably limited. CONCLUSIONS: There was a noteworthy deficiency in PID work-up. Therefore, implementing effective educational strategies is needed to improve the competency of pediatricians to diagnose and manage PID disorders.

Report of two unrelated patients with hereditary vitamin D resistant rickets due to the same novel mutation in the vitamin D receptor.

BACKGROUND/AIMS: Two unrelated patients found to have hereditary vitamin D resistant rickets (HVDRR) were admitted to our hospital. METHODS: This article describes the diagnosis, management and molecular basis for their disease. RESULTS: Both patients had severe growth and motor developmental retardation, rickets with chest deformities and pulmonary abnormalities, but no alopecia. Both had hypocalcemia, secondary hyperparathyroidism and susceptibility to pulmonary infections. In both cases, good response with normalization of abnormal biochemistries and healing of rickets was achieved with IV calcium infusion. Subsequently, improvement was maintained with oral calcium. Both children harbored the same unique missense mutation in the vitamin D receptor (VDR) gene that substituted arginine with histidine at amino acid 274 (R274H) in the VDR ligand-binding domain (LBD). R274 is a contact point for the 1alpha-hydroxyl group of 1,25(OH)2D3, the active ligand for the VDR. Functional analyses of the R274H mutation revealed a 100-fold decrease in activity compared to wild-type VDR. CONCLUSION: We describe a novel missense mutation at R274H in the VDR gene that resulted in the HVDRR syndrome in two unrelated children. Vigorous treatment using IV calcium to normalize their hypocalcemia achieved dramatic improvement in these complex and severely ill patients.