Alterations in lymphocyte subsets as prognosticators of postoperative infections.

OBJECTIVE

To evaluate changes in lymphocyte subsets after major abdominal and thoracic operations, and to correlate changes with the development of clinically relevant infections postoperatively.

DESIGN

Open study.

SETTING

University hospital, Italy.

SUBJECTS

33 patients who were to undergo major abdominal or thoracic operations.

INTERVENTIONS

Lymphocyte subsets were measured by cytofluorimetry before operation and 1, 3, 5, and 7 days postoperatively.

MAIN OUTCOME MEASURES

Correlation between changes in the number of lymphocyte subsets and development of infection.

RESULTS

Lymphocyte subsets were within the reference range in all patients before operation. 10/33 Patients developed infections (pneumonia, bacteraemia, or wound or urinary tract infections) between the second and the ninth days postoperatively (30%). On day 1 the numbers of all lymphocyte subsets had decreased significantly compared with the preoperative measurements in all patients (CD3 p < 0.01, CD4 p < 0.001, and CD8 p < 0.05). The reduction in CD3 was significantly greater in the group that developed infections (p < 0.001). Among patients who did not develop infections the numbers of lymphocyte subsets had returned to the reference range within a week of operation whereas among patients who developed infections they remained depressed (p < 0.05).

CONCLUSION

The synchronous reduction in numbers of all lymphocyte subsets on the first day postoperatively to below 50% of the reference range (CD3 to < 600/microliters, CD4 to < 400/microliters, and CD8 to < 250/microliters) predicted the development of infection postoperatively with an accuracy of 89%, a sensitivity of 80%, and a specificity of 96%.