Clinical Significance of Elevated Levels of Cardiac Troponin T in Patients with Chronic Kidney Disease at Lagos University Teaching Hospital, Lagos.

BACKGROUND: This is an observational study of pre-dialysis patients with Chronic Kidney Disease (CKD) attending nephrology clinic at Lagos University Teaching Hospital to determine the clinical significance of elevated levels of Cardiac Troponin T (CTT) and possible associated factors. METHODS: One hundred and forty-three (143) patients with CKD and no prior history of myocardial infarction were recruited and their serum levels of CTT were determined within 3 months of sample collection and storage at -80° C. ECG findings and clinical variables were compared. The 99 percentile cut-off value was derived using healthy individuals that met the inclusion criteria. RESULTS: Mean blood CTT level was significantly higher in CKD patients compared to the general population. The 99th percentile value derived in the reference sample population was 48.02pg/ml. Statistical analysis showed significant association of CTT elevation with left ventricular hypertrophy, decreased renal function and age. CONCLUSION: CTT is generally elevated in pre-dialysis patients with CKD and a single elevated blood level of CTT above the 99th percentile may suggest asymptomatic Acute Coronary Syndrome. Serial rising levels of CTT and other clinical features will be of diagnostic significance in the diagnosis and management of asymptomatic acute coronary syndrome in patients with CKD.

CONTEXTE: Étude observationnelle de patients prédialysés atteints d'une maladie rénale chronique (MRC) fréquentant une clinique de néphrologie de l'hôpital universitaire de Lagos afin de déterminer la signification clinique des niveaux élevés de troponine cardiaque T (TTC) et des facteurs associés possibles. METHODESS: Cent quarante-trois (143) patients atteints de MRC et aucun antécédent d'infarctus du myocarde ont été recrutés et leurs taux sériques de TTC ont été déterminés dans les 3 mois suivant le prélèvement et le stockage de l'échantillon à -80 °C. Les résultats de l'ECG et les variables cliniques ont été comparés. La valeur seuil du 99e centile a été calculée à partir de personnes en bonne santé qui répondaient aux critères d'inclusion. RESULTATSS: Le taux moyen de TTC dans le sang était significativement plus élevé chez les patients atteints de MRC que dans la population générale. La valeur du 99e centile calculée dans la population de l'échantillon de référence était de 48,02pg/ml. L'analyse statistique a montré l'association significative de l'altitude de TTC avec l'hypertrophie ventriculaire gauche, la fonction rénale diminuée et l'âge. CONCLUSION: Le CTT est généralement élevé dans les patients de pré-dialyse atteints de MRC et un taux sanguin élevé simple de CTT au-dessus du 99ème centile peut suggérer ACS qui n'a pas été remarqué. Les niveaux ascendants périodiques de CTT et d'autres dispositifs cliniques seront d'importance diagnostique dans le diagnostic et la gestion de ces patients atteints de MRC mais asymptomatique pour le syndrome coronaire aigu. MOTS-CLÉS: Troponine cardiaque T, Syndrome coronarien aigu, Maladie rénale chronique, hypertrophie ventriculaire gauche.

The incidence of electrolyte and acid-base abnormalities in critically ill patients using point of care testing (i-STAT portable analyser).

BACKGROUND: Electrolytes and acid-base disorders are common challenges seen in the intensive care unit (ICU) resulting in difficulty in weaning patients off the ventilator, prolonged admission periods, preventable cardiac arrhythmias and cardiac arrest. These require prompt lab results most of which are done serially, ideally a point of care test (POCT), as most central hospital lab result's turnaround time (TAT) sometimes might not meet up with the urgency of clinical decision making in the ICU. OBJECTIVE: To determine the incidence of electrolytes and acid-base abnormalities using i-Stat portable analysers in the ICU of the Lagos University Teaching Hospital (LUTH). METHOD: The i-STAT Portable Clinical Analyzer, a POCT system consisting of a hand-held analyzer and single-use cartridges that measure different panels of analytes in 65-100 microl of blood using an EC8+ cartridge type analyzer for sodium, potassium, chloride, urea, glucose, pH, blood gases [TCO2, pO2, pCO2]) and heamatocrit was used. RESULTS: Over 66.78% of the patients had multiple electrolytes and acid-base abnormalities. Azotemia in 20%, hypoglycaemia in 13.33%, and hyperglycaemia in 53.33% of patients. CONCLUSION: it is concluded from this study that electrolyte and acid base abnormalities is not uncommon in the intensive care unit of LUTH and the i-STAT Portable Clinical Analyzer was helpful in facilitating early diagnosis and treatment.

The value of percentage free prostate specific antigen (PSA) in the detection of prostate cancer among patients with intermediate levels of total PSA (4.0-10.0 ng/mL) in Nigeria.

OBJECTIVES: To assess the value of percentage free prostate-specific antigen (%fPSA) in the detection of prostate cancer among Nigerian men with an intermediate total PSA level (4-10 ng/mL), and to show if the optimum threshold for biopsy is different from Caucasian values when the widely used (six-core, digitally directed) prostate biopsy protocol in Nigerians is applied. PATIENTS AND METHODS: The study included 105 patients aged >50 years, with a palpably benign prostate gland and intermediate levels of total PSA (4-10 ng/mL). These patients had a free PSA assay and a transrectal digitally directed six-core biopsy of the prostate. The %fPSA was calculated and the optimum threshold value for detecting prostate cancer was determined. RESULTS: The mean (SD) age of the patients was 64.4 (6.6) years and their mean (SD) total PSA level was 6.6 (1.7) ng/mL. Of these men 14 (13.3%) had cancer of the prostate detected by the prostate biopsy. The %fPSA level related directly to sensitivity values but inversely to the specificity and the positive predictive values. The best threshold of %fPSA for detecting cancer in these men was <40%, with a sensitivity of 100%, specificity of 93.4% and a positive predictive value of 70% (P < 0.05). CONCLUSIONS: In evaluating Nigerian patients with a palpably benign prostate gland and within the intermediate total PSA range, when digitally directed biopsy protocol is adopted, a %fPSA threshold of <40% will detect significant percentage of those with prostate cancer, with a minimal number of unnecessary biopsies. This value differs from that reported in western studies in which transrectal ultrasonography-directed biopsy was used.

Serum cystatin C levels in Nigerian children: reference intervals and relationship to demographic and anthropometric variables.

BACKGROUND: Cystatin C has been recognized as a good marker of kidney function but reference ranges have not been determined in Nigerian children. OBJECTIVE: To determine the reference range of serum cystatin C in Nigerian children with no overt signs of kidney disease and to determine and compare the relationship of serum cystatin C and serum creatinine with demographic and anthropometric variables. METHODS: Fifty-nine children aged two years to 16 years with no evidence of overt kidney disease were recruited from the Paediatric Clinics of the Lagos University Teaching Hospital. Serum cystatin C levels were measured using ELISA method while serum creatinine was measured by a rate-blanked and compensated Jaffe method using a Roche/Hitachi 902 auto-analyser. Both were measured using the same serum sample. RESULTS: The mean (±1.96SD) serum cystatin C level was 0.73 (0.41-1.04) mg/L and was similar among male and female children (P=0.640) and between children younger than five years and those five years and older (P=0.596). Unlike cystatin C, serum creatinine was higher among children five years or older. In contrast to serum creatinine, serum cystatin showed no significant correlation with age (r=0.153, P=0.246), weight (r=0.062, P=0.641) and length (r=0.067, P=0.612). CONCLUSION: Serum cystatin C reference range in Nigerian children is similar to that reported for children in other regions of the world and appears to be independent of gender, weight, height, body mass index and age after two years.