Inflammatory response in 85 patients with loosened hip prostheses: a prospective study comparing inflammatory markers in patients with aseptic and septic prosthetic loosening.

BACKGROUND: The most common complications of prosthetic hip joints are aseptic mechanical failure and infection. Delayed low-grade infections are seen most often, and they are also most difficult to distinguish from aseptic mechanical failures. METHODS: We conducted a prospective study to compare inflammatory markers in patients diagnosed with aseptic or septic prosthetic loosening. The diagnostic criteria were based on the decisions of experienced orthopedic surgeons and microbiological analysis of periprosthetic tissue samples taken perioperatively. RESULTS: Coagulase-negative staphylococci were the commonest pathogens in the infected patients. Pre- or perioperative elevation of C-reactive protein and erythrocyte sedimentation rate were significantly greater in the infection group, as were white blood cell count and levels of cytokines in synovial fluid. The patterns of infiltration of inflammatory cells in periprosthetic tissue were also significantly different between the groups. INTERPRETATION: A combination of clinical judgment and multiple tissue samples constitutes a good platform for distinguishing between septic and aseptic loosening of prostheses. Moreover, the combined use of several laboratory and histopathological markers of inflammation, especially infiltration of polymorphonuclear cells, further helps the diagnosis.

IL-8 and tumor necrosis factor alpha in heart valves from patients with infective endocarditis.

The embedding of bacteria in the vegetation of infective endocarditis impedes the penetration of phagocytic cells. IL-8 has a stimulating effect on the immune system, particularly with respect to chemotaxis and activation of granulocytes. Tumor necrosis factor alpha (TNF-alpha) is 1 of the major proinflammatory cytokines. IL-8 and TNF-alpha were visualized by means of immunohistochemistry in paraffin-embedded heart valve biopsies from 6 patients with infective endocarditis who required cardiac surgery during the active phase of the infection. In 5/6 patients there were signs of inflammation, and in these patients IL-8- and TNF-alpha-containing cells were visualized in the heart valve stromas or vegetations. The largest numbers of IL-8-containing cells, and the greatest amount of inflammation, were seen in patients with short preoperative treatment courses. No such relationships were seen with respect to TNF-alpha-containing cells. These observations may suggest that the occurrence of IL-8-containing cells in infected heart valves could be used as a marker of disease activity.

Prognostic implications of declining plasma gelsolin levels after allogeneic stem cell transplantation.

The idiopathic pneumonia syndrome (IPS) represents a common and often fatal complication of hematopoietic stem cell transplantation (HSCT). Gelsolin is a highly conserved actin-binding protein normally present in plasma that may serve a basic physiological role in limiting acute lung injury of diverse etiologies. We hypothesized that depletion of circulating gelsolin following HSCT might play a permissive role in the pathogenesis of IPS. Plasma gelsolin levels were measured by immunoblotting in frozen samples obtained weekly from 24 patients undergoing allogeneic HSCT. Patients with and without IPS were similar with respect to age, diagnosis, histocompatibility differences between donor and recipient, and conditioning regimen. Mean gelsolin levels in the 9 patients with rapidly fatal IPS were significantly lower than those in patients without this complication by week 3 after HSCT (101 +/- 61 mg/L versus 221 +/- 54 mg/L; P =.0002). Seven (88%) of the 8 patients with gelsolin levels of less than 100 mg/L in the first month after HSCT died from IPS within 3 months; conversely, gelsolin levels fell to less than 100 mg/L in 7 (78%) of the 9 patients who died from IPS within 3 months of HSCT (P =.0007). These findings suggest that gelsolin levels shortly after allogeneic HSCT can predict the later development of fatal IPS. Gelsolin replacement in selected transplant patients may offer a novel strategy to prevent or reverse IPS.