Impact of severe lymphopenia on outcome of patients with pneumonia and positive pneumococcal urinary antigen

Abstract

<b>Purpose:</b> Evaluate the impact of severe lymphopenia on in-hospital course and outcome in patients hospitalized with pneumococcal pneumonia (PP) and positive urinary antigen test (UAT) at admission.&nbsp;Methods: Prospective observational study, including all consecutive immunocompetent adults hospitalized for PP in 2 hospitals for a 19-year period. The bacteriological diagnosis was based on the result of UAT performed at admission. Generalized additive models (GAM) were constructed to assess the smooth relationship between lymphopenia and in-hospital mortality.&nbsp;Severe lymphopenia was defined according to the CTCAE 2017 classification (lymphocyte count &lt; 500/mm3 in blood sample drawn at admission).&nbsp;Results:1173 patients. Severe lymphopenia documented in 282 patients (24%). Overall 59 patients died, of whom 30 had severe lymphopenia. Table 1:factors associated with in-hospital course and outcome of patients with severe lymphopenia. Figure 1: effect of severe lymphopenia on in-hospital mortality. Figure 2: Kaplan-Meier curve for 30-day mortality according to lymphocyte count. <b>Conclusion:</b> 1. Severe lymphopenia is an independent&nbsp;predictor of 30-day mortality and severity&nbsp;in patients with PP and&nbsp;positive urinary antigen. 2. Early performance on hospital admission of pneumococcal urinary antigen and&nbsp;lymphocyte count could help to stratify severity and contribute to individualize clinical management in pneumonia.