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BACKGROUND: The 24-hour (24-h) creatinine clearance (CrCl) is the most common method for measuring GFR in clinical laboratories. However, the limitations of CrCl have resulted in the widespread acceptance of mathematically derived estimated glomerular filtration rate (eGFR) using Cockcroft-Gault (CG), Modification of Diet in Renal Disease (MDRD) and the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations in predicting eGFR. The aim of the study was to compare 24-h CrCl with eGFR derived from these formulae and to identify which could be the best alternative. METHOD: A prospective study was conducted involving 140 CKD patients. Creatinine and cystatin C concentrations were determined using the cobas 6000 analyzer. The eGFR was calculated using the CG formula, 4-variable MDRD and CKD-EPI equations, and Bland-Alman plots bias was determined. RESULTS: The CG and MDRD formulas had mean eGFR values similar to CrCl and correlation coefficients (r) were highest for CG (0.906) and lowest for MDRD (0.799). The CG equation was in agreement with 24-h CrCl in all but stage V CKD while the MDRD equation compared well in all except Stage IV CKD. The CG equation was positively biased (0.9857) while the MDRD had a negative bias (-0.05). CONCLUSION: The Cockcroft-Gault formula provides a more accurate assessment of GFR than 24-h CrCl and would be recommended as a substitute to provide the best estimate of GFR in our population.
RESUMO
BACKGROUND: The progression of chronic kidney disease (CKD) is concomitant with complications, including thyroid dysfunction, dyslipidemia and cardiovascular diseases. The aim of this study is to determine serum cystatin C levels, and the prevalence of vitamin D deficiency and thyroid dysfunction in CKD patients. METHODS: A cross-sectional study was conducted involving 140 CKD patients (stages 1-5) that were referred to a renal clinic. Demographic data was collected and thyroid function tests, serum 25-OH-vitamin D, cystatin C levels, and routine biochemistry tests were determined using cobas 6000 analyzer. RESULTS: 129 (92.1%) of CKD patients had elevated serum cystatin C levels and there was a stepwise increase from stage 1-5. Overt hypothyroidism was present in one patient and nine had subclinical hypothyroidism. There was a stepwise reduction in serum 25-OH-vitamin D levels from stage 2-5, 31 (22.1%) had vitamin D insufficiency and 31 (22.1%) presented with deficiency. CONCLUSIONS: 25-OH-vitamin D deficiency and thyroid disorders are exhibited in chronic kidney disease patients and the severity of the former rises with disease progression, as indicated by elevated cystatin C levels. Routine screening and timely intervention is recommended so as to reduce the risk of cardiovascular diseases.
RESUMO
INTRODUCTION: The Chemical Pathology Laboratory at the University Hospital of the West Indies (UHWI) processes specimens received from inpatients, the outpatient department and other medical facilities in Jamaica. Specific rejection criteria are used to determine samples unsuitable for analysis. It has been noted that despite efforts to reduce the number of unacceptable samples received in the laboratory, the problem persists. AIM: The study seeks to provide empirical evidence of the inadequacies from which improvements can be formulated. MATERIALS AND METHODS: Errors recorded in the rejection log in the Chemical Pathology laboratory at the University Hospital of the West Indies for the period were assessed. The types and frequency of errors were determined manually. The yearly rejection ratios over a four-year period were evaluated. RESULTS: The most common causes for rejection were unlabelled samples (37%), incorrectly labelled specimens (23%), samples submitted in an inappropriate tube (14%) and incomplete or inaccurately completed requisition forms (14%). The rejection ratio for 2015-2016 was 2.1%. CONCLUSION: The laboratory must initiate programmes directed at improving the preanalytical process in order to ensure patient safety.