Abstract:BackgroundThe clinical features and outcome of prosthetic joint infection (PJI) among solid organ transplant (SOT) recipients have not been characterized. We performed a retrospective, matched case‐control study to examine potential risk factors.MethodsWe reviewed cases ofPJIamong transplant recipients who were evaluated at the Mayo Clinic between 1989 and 2009. Cases were matched to non‐infected controls based on transplant type, prosthetic joint type, and order of organ transplantation/joint implantation.ResultsAmong 367 patients with both a joint prosthesis and anSOT, there were 12 cases of infection in those receiving immunosuppression. These occurred in 8 renal recipients, 3 liver recipients, and 1 heart transplant recipient. Six subjects had hip and 6 had knee arthroplasty infections. The observed time to prosthesis failure ranged from 0.5 to 148 months after implantation. Gram‐positive bacteria (staphylococci and streptococci) caused the infection in 8 subjects. Two cases were caused by nontuberculous mycobacteria, whereas the remaining 2 cases were culture‐negative in the setting of antimicrobial use. We did not find a statistically significant association between obesity, diabetes mellitus, or antimicrobial prophylaxis (given in the setting of immunosuppression) and development ofPJI. A marginal association was seen betweensurgical site infectionand the risk ofPJI; however, this did not reach statistical significance.ConclusionIn our series, infection was mainly caused by gram‐positive bacterial pathogens, similar to the commonly encountered organisms in the immunocompetent host, although opportunistic pathogens were also isolated.
Conversion to Sirolimus as Primary Immunosuppression Attenuates the Progression of Allograft Vasculopathy After Cardiac Transplantation
Background— We investigated the potential of conversion to sirolimus (SRL) as a primary immunosuppressant in attenuating cardiac allograft vasculopathy progression. Methods and Results— Twenty-nine cardiac transplant recipients were converted to SRL 3.8±3.4 years after transplantation with complete calcineurin inhibitor (CNI) withdrawal. Secondary immunosuppressants (azathioprine or mycophenolate) and steroids remained unchanged. Forty patients (controls) 4.8±4.0 years from transplantation were maintained on CNIs. Three-dimensional intravascular ultrasound studies were performed at baseline and 12.1±2.6 months later. Mean plaque (media and intima) volume (PV) and plaque index (PI) (PV/vessel volume percent) increased significantly in the CNI group (1.28±2.86 mm 3 /mm, P =0.004; and 6±8%, P =0.0001) but not in the SRL group (0.1±1.13 mm 3 /mm, P =0.63; and 0.1±8%, P =0.94). In patients enrolled within 2 years after transplantation, the increases in PV (0.06±1.06 versus 1.77±1.65 mm 3 /mm; P =0.0081) and PI (0±9% versus 10±8%; P =0.0145) were smaller in the SRL group (n=11) than in the CNI (n=12) group. In patients enrolled ≥2 years after transplantation, the increase in PI was less in the SRL group compared with the CNI group (0.1±6.5% versus 5±8%; P =0.033), but changes in PV did not differ significantly. Treatment with azathioprine or mycophenolate did not affect PV or PI in either the SRL group (PV: 0.22±0.66 versus 0.05±1.45 mm 3 /mm, P =0.46; PI: 1.5±6% versus −1.6±8.5%, P =0.29) or the CNI group (PV: 1.42±1.39 versus 1.06±2.28 mm 3 /mm, P =0.49; PI: 7.8±8.7% versus 4.8±7.3%, P =0.23). Conclusions— Substituting CNI with SRL as primary immunosuppression attenuates cardiac allograft vasculopathy progression.
Comparative Quantitation of Cytomegalovirus (CMV) DNA in Solid Organ Transplant Recipients with CMV Infection by Using Two High-Throughput Automated Systems
ABSTRACT Cytomegalovirus (CMV) DNA quantitation in clinical specimens is progressively becoming a cornerstone in the diagnosis and management of CMV infection in the immunocompromised host. We evaluated two automated and reproducible PCR tests, the LightCycler (Roche Molecular Biochemicals, Indianapolis, Ind.) and the COBAS AMPLICOR CMV Monitor (Roche Diagnostics, Pleasanton, Calif.), for the detection of CMV DNA in blood samples from transplant recipients with CMV infection as determined by shell vial culture. Following a log transformation analysis, the mean CMV DNA in plasma (PL), whole blood (WB), peripheral blood leukocytes (PBL), and peripheral blood mononuclear cells (PBMC) using the LightCycler was 6.79 copies per ml, 7.23 copies per ml, 6.38 copies per 2 × 10 6 cells, and 6.27 copies per 2 × 10 6 cells, respectively. This compares to 7.86 copies per ml, 8.37 copies per ml, 7.59 copies per 2 × 10 6 cells, and 7.44 copies per 2 × 10 6 cells, respectively, using COBAS AMPLICOR CMV Monitor. While higher CMV DNA levels were observed for the various blood compartments analyzed using COBAS AMPLICOR CMV Monitor, a high degree of correlation was evident between the two automated systems (jackknife correlation r = PL 0.77 [95% confidence interval (CI); 0.64, 0.90], WB 0.77 [95% CI; 0.62, 0.92], PBL 0.77 [95% CI; 0.67, 0.88], and PBMC 0.81 [95% CI; 0.72, 0.89], all P < 0.001). Therefore, we conclude that either automated diagnostic system is accurate for CMV DNA quantitation.