Toxoplasmosis after hematopoietic stem cell transplantation

Area of Science:

• Infectious Diseases
• Hematology
• Transplantation Medicine

Background:

• Toxoplasmosis is a significant opportunistic infection in immunocompromised patients.
• Allogeneic hematopoietic stem cell transplantation (HSCT) recipients are at high risk for severe toxoplasmosis.
• Graft-versus-host disease (GVHD) is a common complication following HSCT, increasing susceptibility.

Purpose of the Study:

• To investigate the incidence, clinical features, and outcomes of toxoplasmosis in European HSCT recipients.
• To identify risk factors associated with mortality from toxoplasmosis post-HSCT.
• To evaluate the role of diagnostic tools like PCR and therapeutic interventions.

Main Methods:

• Retrospective analysis of 41 toxoplasmosis cases across 15 European centers (1994-1998).
• Data collection on patient serostatus, GVHD, organ involvement, diagnostic methods (including PCR), antimicrobial prophylaxis, and treatment.
• Statistical analysis including univariate and multivariate assessments of mortality risk factors.

Main Results:

• High incidence of toxoplasmosis (41 cases) in HSCT recipients, with most patients seropositive pre-transplant.
• Majority of patients had organ involvement; 73% lacked anti-Toxoplasma prophylaxis.
• Mortality rate was high (63%), but adequate therapy and late-onset infection (>63 days post-HSCT) were associated with lower mortality risk.

Conclusions:

• Toxoplasmosis post-HSCT is a severe complication with substantial mortality.
• Early diagnosis, potentially aided by PCR, and prompt, adequate anti-Toxoplasma therapy are crucial for improving outcomes.
• Prophylaxis and vigilant monitoring are essential in HSCT recipients, especially those with GVHD.