Impact of solid organ transplantation and immunosuppression on fever, leukocytosis, and physiologic response during bacterial and fungal infections

Immunosuppressed solid organ transplant patients may exhibit a blunted response to infection compared to non-transplant patients. To test this hypothesis, we prospectively identified all episodes of bacterial and fungal infection on the in-patient abdominal organ transplant service in our hospital, in 1997, and compared them to infected general surgery and trauma admissions treated simultaneously on the same wards. Eighty-two infections occurred in transplant patients versus 463 in non-transplant patients. Transplant patients demonstrated an overall greater physiologic response [Acute Physiology and Chronic Health Evaluation (APACHE II) and Acute Physiology Scores (APS) at the time of infection of 17.0 ± 0.7 and 10.3 ± 0.6, respectively, vs. 12.2 ± 0.4 and 8.0 ± 0.3 for non-transplant patients, p ≤ 0.003], with a similar maximum temperature (38.0 ± 0.1 vs. 38.2 ± 0.1°C, p = 0.2) and white blood cell (WBC) count (12.1 ± 1.0 vs. 13.9 ± 0.4 k/mL, p = 0.08). Upon further analysis of subgroups, patients receiving mycophenolate or azathioprine had significantly lower maximum temperatures (37.9 ± 0.2°C) and WBC counts (11.0 ± 0.9 k/mL) when compared to non-transplant patients, while steroids appeared to have little effect on the systemic inflammatory response. Overall mortality was similar between groups. In general, solid organ transplant recipients exhibit a physiologic response to bacterial or fungal infection (as measured by the APS) at least as great as that seen in non-transplant surgical patients, although mycophenolate and azathioprine appear to slightly depress the ability to respond with fever and leukocytosis. None of these differences appeared to affect overall mortality.