Pediatric reference intervals for endocrine markers in healthy children and adolescents on the Liaison XL (DiaSorin) immunoassay system.

OBJECTIVES: Prominent physiological changes occurring throughout childhood and adolescence necessitate the consideration of age and sex in biomarker interpretation. Critical gaps exist in pediatric reference intervals (RIs) for specialized endocrine markers, despite expected influence of growth and development. The current study aimed to establish and/or verify RIs for six specialized endocrine markers on a specialized immunoassay system. METHODS: Samples were collected from healthy children and adolescents (5 to <19 years) and apparently healthy outpatients (0 to <5 years) as part of the Canadian Laboratory Initiative on Pediatric Reference Intervals (CALIPER). Serum samples were analysed for aldosterone, renin (plasma), thyroglobulin, anti-thyroglobulin, growth hormone, and insulin-like growth factor-1 (IGF-1) on the Liaison XL (DiaSorin) immunoassay platform. RIs (2.5th and 97.5th percentiles) were established for aldosterone, renin, thyroglobulin, anti-thyroglobulin, and growth hormone. Manufacturer-recommended pediatric RIs for IGF-1 were verified. RESULTS: Age-specific RIs were established for aldosterone, renin, and thyroglobulin, while no age-specific differences were observed for anti-thyroglobulin or growth hormone. IGF-1 was the only endocrine marker studied that demonstrated significant sex-specific differences. Manufacturer-recommended IGF-1 RIs were verified for children aged 6 to <19 years, while those for children aged 0 to <6 years did not verify. CONCLUSIONS: This study marks the first time that pediatric RIs for aldosterone and renin were established in the CALIPER cohort and highlights the dynamic changes that occur in water and sodium homeostasis during the first years of life. Overall, these data will assist pediatric clinical laboratories in test result interpretation and improve clinical decision-making for patients tested using Liaison immunoassays.

Overview of Laboratory Testing and Clinical Presentations of Complement Deficiencies and Dysregulation.

Historically, complement disorders have been attributed to immunodeficiency associated with severe or frequent infection. More recently, however, complement has been recognized for its role in inflammation, autoimmune disorders, and vision loss. This paradigm shift requires a fundamental change in how complement testing is performed and interpreted. Here, we provide an overview of the complement pathways and summarize recent literature related to hereditary and acquired angioedema, infectious diseases, autoimmunity, and age-related macular degeneration. The impact of complement dysregulation in atypical hemolytic uremic syndrome, paroxysmal nocturnal hemoglobinuria, and C3 glomerulopathies is also described. The advent of therapeutics such as eculizumab and other complement inhibitors has driven the need to more fully understand complement to facilitate diagnosis and monitoring. In this report, we review analytical methods and discuss challenges for the clinical laboratory in measuring this complex biochemical system.

[Erinit biotransformation and a structural study of its dominant metabolite]. / Biotransformatsiia érinita i izuchenie struktury ego dominantnogo metabolita.

Chromatographic and spectral methods were used for the study. The structural formula of erinit dominant metabolite was worked out on the base of IR-and mass-spectrometry data. It was glucuronide-penta-erythrite-trinitrate, isolated from the urine of patients with cardiac ischemia.