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The article discusses the imprecision of point-of-care testing (POCT) for capillary blood glucose measurements in neonates and its impact on managing hypoglycemia. Topics include the variability of glucose readings, factors influencing accuracy, and practical recommendations for pediatricians when interpreting POCT results.

Introduction: A patient presented to hospital with chest pain and shortness of breath on 2 occasions 4 weeks apart. Clinical examination revealed an elevated jugular venous pressure consistent with heart failure or elevated filling pressures. Methods: The patient was investigated through various modalities including electrocardiogram (ECG), transthoracic echocardiogram, coronary angiography, MRI, cardiac catheterization, positron emission tomography, and an extensive laboratory workup. Results: Serial hs TnI measurements consistently revealed grossly elevated troponin I (>10 000 ng/L). In-lab investigation of increased high sensitivity troponin I (hsTnI) showed evidence of falsely increased troponin due to the presence of heterophilic antibodies. Discussion: This case demonstrates a complex patient presentation and the value of involving the laboratory medicine team when dealing with potentially discrepant results. This is a rare report of grossly elevated troponin due to heterophilic antibodies for high-sensitivity troponin Abbott assay. [ABSTRACT FROM AUTHOR]

Background: In North America, both messenger RNA (mRNA) vaccines, Pfizer-BioNTech BNT162b2, and Moderna mRNA-1273, each utilizing a 2-dose regimen, have started to be administered to individuals. Methods: We evaluated the quantitative serologic antibody response following administration of either a single dose or both doses of an mRNA severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine in a cohort of 98 participants (88 healthcare workers [HCW] and 10 solid organ transplant [SOT] recipients). Antibody levels were compared across 3 immunoassays: Elecsys Anti-SARS-CoV-2 S (Roche Diagnostics), SARS-CoV-2 TrimericS IgG (DiaSorin), and SARS-CoV-2 IgG II Quant (Abbott). Results: Among HCW, sensitivity ranged from 100% (Roche), 99% (Abbott) and 98% (DiaSorin). The SARS-CoV-2 IgG II Quant and SARS-CoV-2 TrimericS IgG assays showed good agreement with a Pearson correlation coefficient of R = 0.95. Pearson correlation coefficients of R = 0.82 and 0.83 were obtained for Elecsys Anti-SARS-CoV-2 S vs SARS-CoV-2 TrimericS IgG and SARS-CoV-2 IgG II Quant vs Elecsys Anti-SARS-CoV-2 S, respectively. Significant differences in antibody levels between HCW and SOT recipients were observed. A decrease in antibody levels from time of vaccine administration to blood draw was evident. Among those with a second dose, an increase in antibody levels with increased time between administration of the first and second dose was observed. Conclusions: The absolute values generated from each of the assay platforms are not interchangeable. Antibody levels differed with increased time between vaccine administration and with increased time between administration of the first and second dose. Further, significant differences in antibody levels between HCW and SOT recipients were observed. [ABSTRACT FROM AUTHOR]

Background: Glucose-6-phosphate dehydrogenase (G6PD)/hemoglobin (Hb) ratio helps detect G6PD deficiency, an X-linked disorder that can be asymptomatic or cause acute hemolytic anemia and chronic hemolysis. We investigated preanalytical, analytical, and postanalytical aspects to optimize G6PD/Hb measurement and interpretation. Methods: G6PD was measured with the Pointe Scientific assay and Hb with Drabkin's reagent on Alinity c® (Abbott Diagnostics). Stability of G6PD/Hb was assessed after 7 and 14 days while stored at 2–8 °C. Stability of hemolysate prepared for G6PD analysis was assessed using QC and patient samples up to 4 h at room temperature or 2–8 °C. Analytical performance specifications including precision, method comparison, linearity, LOQ, and carry-over were established for the enzymatic reaction of G6PD and spectrophotometric reading of Hb. G6PD/Hb reference interval and cut-offs were established indirectly using truncated maximum likelihood method (TML) using retrospective data (n = 4715 patient data points). Results: Samples were stable after 7 days at 2–8°C, unless grossly hemolyzed. Hemolysate prepared for G6PD measurement remained stable for up to 4 h for QC at room temperature and 2–8°C, but up to 30 min–1 h at room temperature and 1–2 h at 2–8 °C for patient samples. Precision, linearity, LOQ, and carryover were acceptable. G6PD/Hb cut-offs were <3.3, ≥3.3, 3.3–8.9, and ≥8.9 U/g Hb for deficient males/females, normal males, intermediate females, and normal females, respectively. Conclusions: In vitro hemolysis and delayed hemolysate analysis significantly reduce G6PD/Hb stability. QC material cannot detect the impact of delayed hemolysate analysis. These findings were foundational for optimizing G6PD/Hb protocols for a new platform and establishing laboratory-specific G6PD/Hb cut-offs. [ABSTRACT FROM AUTHOR]

Background: When a test result is critically abnormal, laboratories notify the responsible caregivers immediately, usually with a phone call. If the same test was ordered repeatedly, our institution has a policy of not notifying the caregiver if the previous result was also critical and within 24 h. We compared our policy with those of several different laboratories in North America and estimated the impact of changing our current policy to calling for all critical results, regardless of the time interval. Methods: Several North American laboratories (n = 15) were surveyed regarding their critical result notification policy. For our institution, we performed a retrospective analysis focusing on critical values in a 5-month period for common chemistry tests. We estimated the effect on volume of calls and the impact on workload with regard to changing the critical result notification policy and critical thresholds. Results: A majority of surveyed laboratories had some form of restriction for calling about recurring critical results. In our institution, removing the restrictions would increase the average number of daily calls by 11%-155%, depending on the analyte. The choice of critical thresholds also has an effect on the number of calls, and the effect depends on the analyte and the threshold chosen. Conclusions: Guidelines do not specify how recurring critical results should be communicated. Depending on the institutional resources, some laboratories call only the first critical result for one or more tests if certain criteria are met. Modification of these policies can lead to significant changes in the volume of calls made by the laboratory and can have numerous impacts related to workload, logistics, and patient care. [ABSTRACT FROM AUTHOR]