Lymphocyte integrin expression differences between SIRS and sepsis patients.

BACKGROUND: Systemic Inflammatory Response Syndrome (SIRS) and sepsis remain leading causes of death. Despite many similarities, the two entities are very distinct clinically and immunologically. T-Lymphocytes play a key pivotal role in the pathogenesis and ultimately outcome following both SIRS and sepsis. Integrins are essential in the trafficking and migration of lymphocytes. They also serve vital roles in efficient wound healing and clearance of infections. Here, we investigate whether integrin expression, specifically ß1 (CD29) and ß2 (CD18), are disrupted in SIRS and sepsis, and assess differences in integrin expression between these two critically ill clinical categories. METHODS: T-Lymphocytes were isolated from whole blood collected from ICU patients exhibiting SIRS or sepsis. Samples were analyzed for CD18 (ß2) and CD29 (ß1) on CD3+ T cells through flow cytometry. Septic patients were stratified into either exclusively abdominal or non-abdominal sources of sepsis. RESULTS: CD18 was almost ubiquitously expressed on CD3+ T cells irrespective of clinical condition. However, CD29 (ß1 integrin) was lowest in SIRS patients (20.4% of CD3+ T cells) when compared with either septic patients (35.5%) or healthy volunteers (54.1%). Furthermore, there was evidence of compartmentalization in septic patients, where abdominal sources had a greater percentage of CD3+CD29+ T cells (41.7%) when compared with those with non-abdominal sources (29.5%). CONCLUSION: Distinct differences in T-cell integrin expression exists between patients in SIRS versus sepsis, as well as relative to the source of sepsis. Further work is needed to understand cause and effect relative to the progression from SIRS into sepsis.

A case of appendiceal diverticulitis, and a review of the literature.

Appendiceal diverticulitis is a rare presentation, often presenting outside of the classical age grouping for appendicitis. We describe a case of appendiceal diverticulitis and issue a cautionary note in the management of patients with atypical features of right lower quadrant pain. In light of its clinical course the finding of a non-inflamed appendiceal diverticulum should prompt one to consider incidental appendicectomy. We also review the literature on appendiceal diverticulitis.