Former Substance Abusers Rarely Relapse After Organ Transplantation

Substance abuse can lead to serious organ diseases for which transplantation is increasingly considered an acceptable treatment. Still, the transplant community remains concerned about these patients resuming their harmful behaviors once the transplant has been done.

Studies have suggested vast disparities in the prevalence of addiction relapse after transplantation, so researchers, led by Mary Amanda Dew of the University of Pittsburgh, conducted a meta-analysis of the existing literature. They sought to establish precise estimates of the rates of alcohol and drug relapse in individuals receiving liver or other solid organ transplants. They also looked for associations between relapse and many pre-transplant or psychosocial characteristics.

The researchers included 54 studies (all but four pertaining to liver recipients) that described more than 3600 former substance abusers who had received transplants. They examined the following post transplant outcomes: alcohol relapse, heavy alcohol use, illicit drug relapse, tobacco use, non adherence to immunosuppressants and nonadherence to clinic appointments.

The average rate for alcohol relapse was 5.6, or approximately 6 cases per 100 persons per year of observation (PPY). The average rate for relapse to heavy alcohol use was 2.5 per 100 PPY. The average relapse to illicit drug use was 3.7 PPY. The average relapse rates for the other studied outcomes ranged from 2 to 10 cases per 100 PPY.

Due to the amount of data available, relapse risk factors could only be assessed for alcohol use. While demographics and pre-transplant characteristics showed little correlation with relapse, poor social support, family alcohol history and pre-transplant abstinence of less than 6 months showed small but significant associations with relapse.

"Future research should focus on improving the prediction of risk for substance abuse relapse, and on testing interventions to promote continued abstinence post-transplant," the authors conclude.

An accompanying editorial by Michael Lucey and colleagues of the University of Wisconsin Medical School et al. congratulates Dew et al "for their outstanding effort to analyze alcohol and drug use after transplantation," while noting that, "for the addiction specialist, the persistence of sobriety after transplantation is surprising and unexplained."

They call for future studies with prospective designs that also separate study personnel from transplant personnel to better identify alcohol and drug relapse, since patients may otherwise conceal their behavior. Further, they conclude based on Dew et al's findings, "we need future studies that confront the issue of the suitability for transplantation of patients with duration of abstinence shorter than six months."

These results are published in the February issue of Liver Transplantation, a journal by John Wiley & Sons.

Article: "Meta-analysis of risk for relapse to substance use after transplantation of the liver or other solid organs." Dew, Mary Amanda; DiMartini, Andrea; Steel, Jennifer; De Vito Dabbs, Annette; Myaskovsky; Larissa; Unruh, Mark; Greenhouse, Joel. Liver Transplantation; February 2008.

Editorial: "Addictive behavior after solid organ transplantation: What do we know already and what do we need to know?" Lucey, Michael; Tome, S.; Said, Adnan. Liver Transplantation; February 2008.