June 2018: Oncology and Transplant ID

Fidaxomycin prophylaxis for C.diff diarrhea in Hematopoetic Stem Cell Transplant recipients is expensive but effective. This study randomized 600 HSCT recipients to C.diff prophylaxis with either once daily fidaxomycin or placebo, beginning when the patients started quinolone prophylaxis and continuing until either a week after engraftment or as long as the patient was getting the quinolone or other antibiotic, up to a maximum of 40 days. Fidaxomycin reduced the incidence of C.diff diarrhea (4.3% vs 10.7%; p=0.0014) and this protective effect persisted for at least 60 days. The number needed to treat to prevent one case of C.diff diarrhea with fidaxomycin prophylaxis was ~16.

So, is it worth the cost of all that fidaxomycin to prevent C.diff in HSCT recipients? Maybe: recent studies have shown that, at least for solid organ transplantation, developing CDI is associated with graft loss, which one imagines is quite expensive. But here's the main question in my mind: even if we decide we must give CDI prophylaxis, why prefer fidaxomicin over oral vancomycin or metronidazole? PMID: 29893798


Fluoroquinolone prophylaxis decreases gram-negative bloodstream infections and mortality in patients receiving high-dose chemotherapy or stem cell transplantation, but at the cost of a higher incidence of ESBL bacteremia. This study out of Europe found that quinolone prophylaxis was associated with a 5.5% absolute risk reduction for mortality in patients receiving high-dose chemotherapy, with less clear benefit for the patients receiving stem cell transplants. Gram-negative bacteremia reduced in incidence by about 5% in prophylaxis recipients, but ESBL bacteremia occurred more frequently (0.8% vs 0.3%; RR 2.2). Previous reports have associated fluroquinolone use with ESBL colonization and infection in a variety of settings. For me, the take home message is to have a higher index of suspicion for ESBL bacteremia when seeing  patients on quinolone prophylaxis with neutropenic fever. PMID: 29883599


In this double-blind RTC, ethanol lock therapy for treatment and secondary prophylaxis of CLABSI in pediatric cancer patients almost doubled the rate of catheter occlusion requiring thrombolytic therapy without reducing treatment failure. I think they should have given the lock therapy orally. It would have been just as effective, and I bet patient satisfaction would have been way higher. PMID: 29884572


Here’s a happy side effect of allowing organ transplantation from HIV-positive donors to HIV-positive recipients: more organs from donors with false-positive HIV tests! This study examined 10 donors with suspected false-positive HIV tests whose organs were distributed to 21 HIV-positive recipients. All 10 patients were subsequently confirmed to have false-positive results. Prior to the HIV Organ Policy Equity act, such donors’ organs were routinely discarded, and based on the prevalence of false positive HIV testing the authors estimate that an additional 50-100 organ donors will be available each year due to this shift in policy. This is great news for people living with HIV, and ultimately it benefits everybody who needs aftermarket parts. PMID: 29947471