In the severe community-acquired pneumonia, it has been known that the immune status is occasionally suppressed. This study was performed to identify the immunologic markers related with the prognostic factors in severe community-acquired pneumonia.

23 patients with severe community-acquired pneumonia were involved in this study, and divided into survivor (16) and nonsurvivor (7) groups. In this study, the medical history, laboratory tests(complete blood counts, routine chemistry profile, immunoglobulins, complements, lymphocyte subsets, cytokines, sputum and blood culture, urine analysis), and chest radiographs were scrutinized.

1) Both groups had lymphopenia(total lymphocyte count 995.6±505.7/mm² in the survivor and 624.0±287.6/mm² in the nonsurvivor group). 2) The T-lymphocyte count of the nonsurvivor group(295.9±203.0/mm²) was lower than the survivor group(723.6±406.5/mm²) (p<0.05). 3) The total serum protein(albumin) was 6.0±1.0(2.7±0.7) g/dl in the survivor and 5.2±1.5(2.3±0.8)g/dl in the nonsurvivor group. The BUN of the noncurvivor group(41.7±30.0mg/dl) was higher than that of the survivor group(18.9±9.8mg/dl)(p<0.05). The creatinine concentration was higher in the nonsurvivor group(1.8±1.0mg/dl) than that in the survivor group(1.0±0.3mg/dl)(p<0.05). 4) The immunoglobulin G level was higher in the survivor group (1433.0±729.5mg/dl) than in the nonsurvivor group(849.1±373.1mg/dl)(p<0.05). 5) The complement C3 level was 108.0±37.9mg/dl in the survivor group and 88.0±32.1mg/dl in the nonsurvivor group. 6) A cytokine study showed an insignificant differenne in both groups. 7) Chronic liver disease, DM, and COPD were major underlying diseases in both groups.

These results suggest that decreased a T-lymphocyte count and immunoglobulin G level, and an increased BUN and creatinine level may be associated with the poor prognosis of severe community-acquired pneumonia.