Clostridium difficile-associated diarrhea in heart transplant recipients: is hypogammaglobulinemia the answer?

Information regarding Clostridium difficile-associated diarrhea (CDAD) after solid-organ transplantation (SOT) is scarce, particularly after heart transplantation (HT). Although host immune response to C. difficile plays a substantial role in the outcome of this infection, the responsibility of hypogammaglobulinemia (HGG) as a predisposing condition for CDAD has not been studied in SOT. We analyzed the incidence, clinical presentation, outcome and risk factors, including HGG, of CDAD after HT.

Two hundred thirty-five patients who underwent HT (1993 to 2005) were included. Transplantation procedure and immunosuppression were standard. From January 1999 HGG was systematically searched and corrected when IgG levels were <400 mg/dl or severe infection was present. Toxin-producing C. difficile was detected by means of cytotoxin assay and culture of stool samples. Patients with and without CDAD were compared for identification of risk factors.

CDAD was detected in 35 patients (14.9%). Incidence decreased significantly since HGG was sought and treated: 29 (20.6%) in the first period, and 6 (6.4%) in the second (p = 0.003). CDAD appeared a mean of 32 days (range 5 to 3,300 days) after HT. No related death or episode of fulminant colitis was detected. At least one episode of recurrence was noted in 28.6% of patients. Severe HGG was found to be the only independent risk factor for CDAD after HT (RR 5.8; 95% CI: 1.05 to 32.1; p = 0.04).

C. difficile is a significant cause of diarrhea in HT recipients and post-transplant HGG is independently associated with an increased risk. The potential role of immunoglobulin administration in this population requires further study.