BACKGROUND: Over the past century, the physicians' view on pneumonia that is inflammatory disease of the lungs with alveolar involvement has undergone several major changes. Emphasis was placed on anatomic location, histopathology and pathogenesis. Recent evidence suggests that cytokine response may be a useful adjunct in diagnosing pneumonia. Acute tissue injury from virtually any cause including infectious diseases will result in rapid increase in the concentrations of several proteins in the serum including C-Reactive Protein (CRP). Several studies have corroborated the role of CRP in the diagnosis of bacterial versus viral meningitis in children and suspected septicemia in neonates. However, its role in the etiological diagnosis of respiratory infections is not well established.

OBJECTIVES: This study sought to (1) determine CRP as a diagnosis marker among patients with community acquired pneumonia (CAP), (2) evaluate the CRP levels among patients with CAP, (3) determine the correlation between CRP, WBC count and segmenters, and (4) determine if bacterial isolate significantly influence the level of CRP.

RESEARCH DESIGN: Prospective Cohort Study

SETTING: Iloilo Mission Hospital, a private tertiary hospital in Iloilo City, Philippines

SUBJECTS: A total of forty one patients 18 years old and above admitted with the diagnosis of CAP from May 1 to November 15, 2004 were included in the study. Expectorated sputum samples were examined and determined suitable for culture if the squamous cells < 5-10/hpf and polymorphonuclear cells > 20-25/hpf. Serum samples for CRP, WBC and segmenters were obtained within the first 24 hours of admission. Descriptive statistics were utilized. The statistical tools employed were means, frequency counts, standard deviation; Pearson's r and serum analysis all set at .05 alpha level of significance.

RESULTS: Fifty eight percent (58 percent) of these patients were classified as CAP moderate risk. Most were males (68 percent) and in their middle adult (56 percent) with mean age of 61. Patients classified as high-risk pneumonia had the highest elevated mean CRP level of 18.87 as compared to patients who were classified as low and moderate risk. Pearson's r was utilized to determine the relationship between CRP, WBC and segmenters. The p-value of 0.05 showed a positive correlation between CRP and segmenters.

CONCLUSIONS: Analysis of the means revealed that Klebsiella pneumonia had the highest CRP mean (89.67). Comparisons of mean CRP by .type of bacteria were found not to be significantly different from each other. Hence bacterial isolate do not influence variability of CRP levels.