Oral Antibiotics for Treatment of Gram-Negative Bacteremia in Solid Organ Transplant Recipients: A Propensity Score Weighted Retrospective Observational Study.

BACKGROUND: We assessed the safety and efficacy of oral antibiotic step-down therapy for uncomplicated gram-negative blood stream infections in solid organ transplant recipients. METHODS: We identified all solid organ transplant recipients within the Massachusetts General and Brigham and Women's Hospital systems from 2016-2021 with uncomplicated gram-negative bacteremia involving an organism susceptible to an acceptably bioavailable oral antibiotic agent. Using inverse probability of treatment-weighted models based on propensity scores adjusting for potential clinical confounders, we compared outcomes of those transitioned to oral antibiotics vs those who continued IV therapy for the duration of treatment. Primary endpoints were mortality, bacteremia recurrence and re-initiation of IV antibiotics. Secondary endpoints included length of stay, C. difficile infection, treatment associated complications and tunneled central venous catheter placement. RESULTS: 120 bacteremia events from 107 patients met inclusion criteria in the oral group and 42 events from 40 patients in the IV group. There were no significant differences in mortality, bacteremia recurrence, or re-initiation of IV antibiotics between groups. Patients transitioned to oral antibiotics had an average length of stay that was 1.97 days shorter (95% CI -0.39, 3.56 days. p = 0.005). Odds of developing C. difficile and other treatment associated complications were 8.4 times higher (95% CI 1.5, 46.6, p = 0.015) and 6.4 times higher (95% CI 1.9-20.9, p = 0.002), respectively, in the IV group. 55% of patients in the IV group required tunneled catheter placement. There was no difference in treatment duration between groups. CONCLUSIONS: Oral step-down therapy was effective and associated with fewer treatment-related adverse events.

Clinicopathologic Features of Tissue Granulomas in Transplant Recipients: A Single Center Study in a Nontuberculosis Endemic Region.

CONTEXT.­: There is a paucity of literature about tissue granulomas in transplant patients. OBJECTIVE.­: To characterize the clinicopathologic features of granulomas in this population and develop a clinically judicious approach to their evaluation. DESIGN.­: We performed chart reviews of solid organ and allogeneic hematopoietic stem cell transplant recipients at Yale New Haven Hospital to identify patients with granulomas on biopsy obtained pathologic specimens. Pretransplant and posttransplant specimens were included. Data points included demographics, clinical presentation, epidemiologic risk factors, biopsy indication, location and timing, immunosuppression, histopathology, microbiology, and associated clinical diagnosis. Granuloma-related readmissions and mortality were recorded at 1, 3, and 12 months. RESULTS.­: Biopsy proven granulomas were identified in 56 of 2139 (2.6%) patients. Of 56, 16 (29%) were infectious. Common infectious etiologies were bartonellosis (n = 3) and cytomegalovirus hepatitis (n = 3). Tuberculosis was not identified. Clinical symptoms prompted tissue biopsy in 27 of 56 (48.2%) cases while biopsies were obtained for evaluation of incidental findings or routine disease surveillance in 29 of 56 (51.8%). Presence of symptoms was significantly associated with infectious etiologies; 11 of 27 (40.7%) symptomatic patients compared with 5 of 29 (17.2%) asymptomatic patients had infectious causes. One death from granulomatous cryptogenic organizing pneumonia occurred. In pretransplant asymptomatic patients, no episodes of symptomatic disease occurred posttransplantation. CONCLUSIONS.­: Granulomas were uncommon in a large transplant population; most were noninfectious but presence of symptoms was associated with infectious etiologies. Granulomas discovered pretransplant without clear infectious etiology likely do not require prolonged surveillance after transplantation. Symptomatology and epidemiologic risks factors should guide extent of microbiologic evaluation.

Update on the nephrotoxicity of novel anticancer agents
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Anticancer drug-induced kidney disease is a problem commonly encountered by nephrologists. The number of medications employed by oncologists causing acute and chronic kidney injury as well as electrolyte and acid-base disturbances has increased significantly over the past several decades. While conventional chemotherapeutic drugs induce a number of kidney lesions, emergence of very effective and well-tolerated targeted therapies and novel immunotherapies has increased the occurrence of drug-induced acute and chronic kidney injury in cancer patients. This article will review the various kidney lesions observed with these new classes of anticancer drugs.
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