Multitest cd3 cd8 cd45 cd4 reagent

All BALF samples were evaluated for cell count and differential and were cultured to detect bacterial and fungal species. Fifteen of the samples also underwent flow cytometry analysis to detect leukocyte surface CD3, CD4 and CD8, and cell counts and percentages were determined using a BD FACSCanto™ II 8-colour cytometer with quantification of T cell subsets performed using BD Multitest CD3/CD8/CD45/CD4 reagent. The number of events collected per sample was 10,000. When able, ventilator parameters were documented for comparative analysis, including PaO₂/FiO₂ ratio, static lung compliance ( $\frac{TidalVolume(mL)}{PlateauPressure-PEEP}$ ), alveolar to arterial (A-a) gradient and positive end-expiratory pressure. Other parameters evaluated included serum inflammatory markers at the day of admission and before bronchoscopy or before positive respiratory culture (C-reactive protein [CRP], ferritin and procalcitonin), serum total white blood cell count, serum neutrophil count, serum lymphocyte count and APACHE-2 scores. A secondary infection was defined as a clinical picture consistent with pneumonia, and a respiratory culture was deemed positive if a BALF/quantitative tracheal lavage sample had bacterial growth >10⁴ or was bacterial PCR positive.