[Value of lymphocyte count in assessing cellular immune function in patients with community-acquired pneumonia]

To investigate the value of lymphocyte count in assessing cellular immune function in patients with community-acquired pneumonia.

Ninety-three patients with community-acquired pneumonia (including 53 non-severe and 40 severe cases) and 52 healthy adults were examined for routine blood test and T lymphocyte count. Blood lymphocyte counts and absolute T lymphocyte counts were compared among the 3 groups and their correlation was analyzed.

Compared with the healthy control subjects, patients with community-acquired pneumonia showed significantly lower blood lymphocyte counts and CD3(+), CD4(+), and CD8(+) levels (P<0.05). CD3(+), CD4(+), and CD8(+) levels were positively correlated with blood lymphocyte counts. With blood lymphocyte count as the independent variable (L), and the regression equations for CD3(+), CD4(+), and CD8(+) levels were CD3(+)=485.45L+313.48 (F=59.68, P<0.01), CD4(+)=192.57L+290.11 (F=24.62, P<0.01), and CD8(+)=275.14L+18.04 (F=23.46, P<0.01) in the control group; CD3(+)=564.15L+25.04 (F=96.56, P<0.01), CD4(+)=381.91L-37.45 (F=68.60, P<0.01), and CD8(+)=165.61L+61.83 (F=55.47, P<0.01) in non-severe pneumonia group; and CD3(+)=565.44L+49.09 (F=31.87, P<0.01), CD4(+)=332.34L-17.37 (F=43.64, P<0.01), and CD8(+)=223.46L+54.39 (F=13.90, P<0.01) in severe pneumonia group.

Patients with community-acquired pneumonia have decreased cellular immune function. Absolute T lymphocyte count can be estimated by blood lymphocyte count to save the cost of laboratory tests.