Neuroapoptosis in newborns with respiratory acidosis at birth.

BACKGROUND: S100B protein is one of the most accurate biomarkers for diagnosis of neuroapoptosis and brain damage. The aim was to evaluate the lactate concentration and acid-base balance (pH, pCO2, pO2, HCO3c and BEb) in umbilical cord blood to predict high risk of neuroapoptosis and analyze the relationship between the levels of these biomarkers and umbilical cord blood S100B protein concentration at birth. METHODS: Apparently healthy newborns were included. S100B protein and blood gas test (lactate and acid-base balance) were determined in umbilical cord blood at birth. Newborns were classified into two groups: with and without high risk of neuroapoptosis. Newborns with high umbilical cord blood S100B protein concentration were considered newborns at high risk of neuroapoptosis. RESULTS: Sixty-one newborns were included, 12 had high risk of neuroapoptosis and 49 did not. S100B protein concentration correlate directly with pCO2 levels (Rho: 0.286, p = .0321) and lactate concentration (Rho: 0.278, p = .0315); and indirectly with pH (Rho: -0.332, p = .01). The analysis of the ROC curves yielded significant curves for pH and pCO2 to predict high risk of neuroapoptosis, pH optimal cutoff value was 7.19 (sensitivity: 50%, specificity: 83.7%, AUC: 0.708); and pCO2 optimal cutoff value was 60 mmHg (sensitivity: 30%, specificity: 85.4%, AUC: 0.705). CONCLUSIONS: Respiratory acidosis is associated to high concentrations of S100B protein in umbilical cord blood at birth. Umbilical cord blood pH and pCO2 may be useful in differentiating newborns at high risk of neuroapoptosis. Umbilical cord blood gas test may be valuable as risk indicator for neuroapoptosis at birth.

Homocysteine: new tumor marker in pleural fluid.

There are no published studies examining the utility of total homocysteine (HCY) in pleural fluid. The aim was to measure the accuracy of pleural fluid HCY concentration for diagnosis of malignant pleural effusion (MPE). We studied pleural fluids obtained by thoracocentesis in patients with pleural effusion. Pleural fluid HCY concentration was measured by immunonephelometry using N Latex HCY reagent with monoclonal antibody in automated analyzers BNII (Siemens Diagnostics®). Patients were classified into two groups according to the etiology of pleural effusion: benign pleural effusions (BPE) and MPE. Pleural effusion was categorized as MPE if malignant cells were demonstrated in pleural fluid or pleural biopsy. The accuracy of pleural fluid HCY concentration for diagnosis of MPE was determined using receiver operating characteristic (ROC) techniques by analyzing the area under the ROC curve (AUC). We studied 89 patients with ages between 1 and 96 years old (median = 66). Forty-eight patients were BPE and 41 were MPE. Pleural fluid HCY concentration was significantly higher in patients with MPE (median = 13.70 µmol/L) than in those with BPE (median = 8.05 µmol/L). The AUC value was 0.833 (95 % confidence interval (CI) 0.739-0.903). The optimal cutoff value was 13.1 µmol/L exhibiting 56.1 % (95 % CI 39.8-71.5) sensitivity and 85.4 % (95 % CI 72.2-93.9) specificity. Pleural fluid HCY concentration showed high diagnostic accuracy to predict whether a pleural effusion is benign or malignant. Pleural fluid HCY concentration may be measured easily and quickly in automated analyzers and could be a tumor marker commonly used for diagnosis of MPE.