Incidence, clinical characteristics and risk factors of late infection in solid organ transplant recipients: data from the RESITRA study group

Information describing the incidence and clinical characteristics of late infection (LI) in solid organ transplantation (SOT) is scarce. The aim of this study was to define the incidence, clinical characteristics and risk factors for LI (>6 months) as compared with infection in the early period (<6 months) after SOT. By the online database of the Spanish Network of Infection in Transplantation (RESITRA) we prospectively analyzed 2702 SOT recipients from September 2003 to February 2005. Univariate and multivariate analysis using logistic regression were performed to calculate the risk factors associated with the development of LI. A total of 131 patients developed 176 LI episodes (8%). Global incidence of LI was 0.4 per 1000 transplant-days, ranging from 0.3/1000 in kidney transplants to 1.4 in lung transplants. Independent risk factors for LI in were: acute rejection in the early period (OR 1.5; CI 95%: 1.1-2.3), chronic graft malfunction (OR 2; CI 95%: 1.4-3), re-operation (OR 1.9; CI 95%: 1.3-2.8) relapsing viral infection apart from CMV (OR 1.9; CI 95%: 1.1-3.5), previous bacterial infection (OR 1.8; CI 95%: 1.2-2.6) and lung transplantation (OR 4.5; CI 95%: 2.6-7.8). Severe LI occurs in a subgroup of high-risk SOT recipients who deserve a more careful follow-up and could benefit from prolonged prophylactic measures similar to that performed in the early period after transplantation.

Is Double Renal Transplantation a Risk Factor for Cytomegalovirus Disease?

We performed a retrospective study to identify the risk factors for cytomegalovirus (CMV) disease among 570 renal transplant recipients. By means of a multivariate analysis we identified antilymphocyte antibody therapy (odds ratio [OR]: 4.6; 95% confidence interval [CI]: 2.0 to 10.6), high doses of corticosteroids (OR: 3.4; 95% CI: 1.2 to 10.1), and double renal transplant (OR: 4.1; 95% CI: 1.5 to 11.5). To the best of our knowledge, this is the first study to suggest that in addition to other well-known risk factors for CMV disease (ie, therapy with anti-lymphocyte antibodies or high doses of corticosteroids), the use of double renal transplantation appears to increase the risk of CMV disease in this population.

Accuracy of blood culture for early diagnosis of mediastinitis in febrile patients after cardiac surgery

Postsurgical mediastinitis (PSM) remains a major cause of morbidity and mortality in patients undergoing cardiac surgery procedures. Although prompt diagnosis is crucial in these patients, neither clinical data nor imaging techniques have shown enough sensitivity or specificity for early diagnosis of PSM. The aim of the present study was to assess the validity of blood cultures as a diagnostic test for the early detection of PSM in patients who become febrile after cardiac surgery procedures. During a 4-year period (1999-2002), patients who developed fever (>37.8 degrees C) in the first 60 days after a cardiac surgery procedure were evaluated. Blood cultures were drawn from these patients. PSM was defined as deep infection involving retrosternal tissue and/or the sternal bone directly observed by the surgeon and confirmed microbiologically. Three criteria for positivity of blood cultures were applied: bacteremia, staphylococcal bacteremia, or Staphylococcus aureus bacteremia. For purposes of the analysis, a positive blood culture in patients with PSM was considered a true-positive test and a negative blood culture a false-negative test. Otherwise, in febrile patients without PSM in the postsurgery period, a positive blood culture was considered a false-positive test and a negative blood culture a true-negative test. Blood cultures were drawn from 266 febrile patients in the postsurgery period. PSM occurred in 38 patients (26 cases due to S. aureus, 8 to Staphylococcus epidermidis, 3 to gram-negative enteric bacteria, and one to Pseudomonas aeruginosa). Within the 60-day postsurgical period, blood culture as a diagnostic test was most accurate in patients with S. aureus bacteremia, providing 68% sensitivity, 98% specificity, a positive predictive value of 87%, and a negative predictive value of 95%. If the analysis was limited to the period during which patients are at maximum risk for PSM (day 7-20), the values in patients with S. aureus bacteremia were as follows: 73% sensitivity, 98% specificity, 90% positive predictive value, and 93% negative predictive value. Blood culture is an accurate test for the early diagnosis of PSM in febrile patients after cardiac surgery, particularly in institutions where S. aureus is prevalent in this context. A negative blood culture practically excludes PSM and, during the period of maximum risk for PSM, the presence of S. aureus bacteremia should compel early surgical management.

[Usefulness of liposomal amphotericin B for the prophylaxis of fungal infection in solid organ transplant recipients]

Solid organ transplantation is the best alternative for the treatment of end-stage kidney, liver, heart, pancreas and lung failure. Fungal infections (the most frequent are Candida spp. and Aspergillus spp.) are associated with highest mortality in solid organ transplantation. The systemic use of liposomal amphotericin B has only been studied in liver transplant recipients. The main conclusions that can be drawn from the five studies that have been published are: 1) for the prophylaxis to be effective against Aspergillus spp., a dose of 5 mg/kg/day must be used; 2) its use must be reserved for situations with the highest risk for invasive fungal infections: retransplantation, the need for resurgery and, mainly, for those patients needing haemodialysis. Preliminary studies for the prophylactic use of nebulized liposomal amphotericin B in lung transplant receptors are promising.

[Symptomatic hyperlactatemia associated with the use of antiretroviral agents]

Lactic acidosis has been reported as a rare but potentially fatal complication of anti-retroviral therapy in HIV-infected patients, mostly with nucleoside analogues. Two cases of lactic acidosis with a favorable prognosis are here reported. So far, no distinct risk factors associated with the development of lactic acidosis have been identified which were associated with the use of anti-retroviral agents, apart from female sex, obesity, and the prolonged use of necleoside reverse transcriptase inhibitors. Currently, there is no specific treatment for this condition, apart from drug discontinuation and hydro-electrolytic support. Several therapies based upon the pathophysiology of this entity have been tested, but none of them has been validated so far.