Lactate dehydrogenase and caspase activity in nasopharyngeal secretions are predictors of bronchiolitis severity

Mehta, Reena; Scheffler, Margaret; Tapia, Lorena; Aideyan, Letisha; Patel, Kirtida D; Jewell, Alan M; Avadhanula, Vasanthi; Mei, Minghua; Garofalo, Roberto P; Piedra, Pedro A

Demographic characteristics among the groups were compared using chi-square test or Fisher's exact test. Analysis of the laboratory data for the continuous variables NW-LDH, NW-caspase 3/7, and NW-LDH/NW-caspase 3/7 ratio compared with demographic data (including disposition) was performed using analysis of variance (ANOVA), Student's t-test, or Wilcoxon-Mann-Whitney tests as appropriate. Given the range of values, the log 10 -transformed values for NW-LDH and NW-caspase 3/7 activity were used for statistical analysis. Correlations were calculated using Pearson's or Spearman's coefficient. For the identification of independent factors that may influence disposition, multivariable logistic regression analyses (polytomous responses) were performed to calculate odds ratio and corresponding 95% confidence intervals. To identify independent factors that influenced NW-LDH, NW-caspase 3/7 and NW-LDH/ NW-caspase 3/7 ratio, multiple linear regression models were developed with two-way interaction effects while controlling for age, gender, race, duration of illness, exposure to cigarette smoke, disposition of patients, virus infection pattern, and the relevant biomarkers. All statistical analyses were performed using the SAS software package version 9.2 (SAS Institute, Inc., Cary, NC, USA).