ABSTRACT
BACKGROUND: We assessed the diagnostic performances of homeostasis model assessment indices (HOMA) of ß-cell function (HOMA-%ß) and of insulin resistance (HOMA-IR) for cystic fibrosis related diabetes (CFRD) screening. METHODS: Data were collected from a prospective cohort of 228 patients with CF (117 adults and 111 children). Fasting insulin and glucose levels were measured to calculate HOMA-%ß and HOMA-IR. HOMA-%ß <100 indicated insulin secretion deficiency and HOMA-IR >1 insulin resistance. Both were used to calculate sensitivity, specificity, and positive and negative predictive values (PPV and NPV). Two-hour oral glucose tolerance tests (2h-OGTT) defined CFRD. Analyses were conducted separately for children and adults. Performances of HOMA-%ß and HOMA-IR were calculated at inclusion, for each year of follow-up and for pooled data over the follow-up period. RESULTS: Sensitivity, specificity, NPV and PPV were respectively: 88%, 45%, 98% and 11% for HOMA-%ß and 42%, 48%, 91% and 6% for HOMA-IR in the pooled data of children; and 83%, 18%, 90% and 10% for HOMA-%ß, and 39%, 80%, 92% and 18% for HOMA-IR in the pooled data of adults. Combining HOMA-%ß and HOMA-IR did not improve performances. CONCLUSION: Within both age groups, HOMA-%ß <100 provided good sensitivity and NPV. HOMA-IR >1 had low sensitivity. Calculation of the HOMA-%ß could be an interesting first-line screening approach to exclude CFRD and thus avoid unnecessary OGTT in patients for whom value is ≥100. However, HOMA-%ß<100 does not support the diagnosis of CFRD and should be complemented by OGTT.
Subject(s)
Blood Glucose/metabolism , Cystic Fibrosis/complications , Diabetes Mellitus/diagnosis , Glucose Tolerance Test , Insulin-Secreting Cells/metabolism , Insulin/blood , Adolescent , Adult , Biomarkers/blood , Child , Cohort Studies , Female , Humans , Insulin Resistance , Male , Predictive Value of Tests , Prospective Studies , Young AdultABSTRACT
We describe an unvaccinated child at risk for life-threatening COVID-19 due to an inherited deficiency of IRF9, which governs ISGF-3-dependent responses to type I and III interferons (IFN). She was admitted, with a high nasal SARS-CoV-2 load on day 1 of upper respiratory tract infection. She was viremic on day 2 and received casirivimab and imdevimab. Her clinical manifestations and viremia disappeared on days 3 and 4, respectively. Circulating SARS-CoV-2 virus induced the expression of IFN-stimulated genes in leukocytes on day 1, whereas the secretion of blood type I IFNs, which peaked on day 4, did not. Antibody-mediated SARS-CoV-2 neutralization is, therefore, sufficient to overcome a deficiency of antiviral IFNs.
