Constituent analysis may permit improved diagnosis of intra-abdominal abscess

Background Intra-abdominal abscesses (IAA) often fail to resolve with intravenous antibiotics alone and frequently require drainage. Diagnosis of IAA in postoperative patients with other likely sources of infection is very difficult. Patients and methods In order to characterize IAA and identify parameters that might facilitate diagnosis, we prospectively examined peripheral blood and pus of 15 consecutive patients with IAA and compared them to samples from 34 consecutive patients with soft-tissue abscesses (STA). Results Serum interleukin (IL)-10 was elevated in IAA patients, while abnormally detectable serum IL-4 was demonstrated in the pus of both IAA and STA patients. IL-10 in IAA pus was more than 11-fold higher than in STA, whereas IL-4 in pus was similar in both types of abscesses. Both IL-4 and IL-10 were 4- to 10-fold higher in IAA and STA pus than in corresponding patient serum. Serum lysozyme was, however, significantly elevated in all abscess patients. Conclusions The presence of IL-4 and IL-10 may indicate a T-helper 2 lymphocyte response in the etiology of abscess formation and persistence, although precise determination of T-helper 1-related cytokines is needed to verify this. Serum lysozyme and IL-10 may be reliable and relatively inexpensive diagnostic aids.