Condition
Toxoplasmosis is a parasitic disease with worldwide distribution. It is caused by the protozoan, Toxoplasma gondii. Though the majority of primary toxoplasmosis infections are asymptomatic, severe cases can present as acute systemic infections [1]. Recently acquired toxoplasmosis or reactivated infections can also present as ocular disease (i.e. posterior uveitis). Immunocompromised individuals are at higher risk for reactivation of a latent infection. Thus, it is more common for reactivation of toxoplasmosis in a seropositive recipient than a donor-transmitted infection [2].
Individual at risk
Recipient
Guidance at RECRUITMENT
ACCEPTABLE if entirely free of symptoms. Defer for donor safety if chronic infection or if clinical manifestation includes ocular disease (i.e. posterior uveitis).
Guidance at CT
ACCEPTABLE if entirely free of symptoms. Defer for donor safety if chronic infection or if clinical manifestation includes ocular disease (i.e. posterior uveitis).
Guidance at WORK-UP
Recommended work-up testing
In countries where all donors must be tested for toxoplasmosis, it is recommended to follow local guidelines / regulation.
Toxoplasmosis-IgM and IgG
Testing outcomes and recommendations
1) Toxoplasmosis IgM = negative AND Toxoplasmosis IgG = positive or negative
Donor can be cleared
2) Toxoplasmosis IgM = positive AND Toxoplasmosis IgG = positive
Avidity testing should be performed to measure the binding strength of specific antibodies to toxoplasmosis antigens. This allows estimation of the time point of primary infection as well as to distinguish between acute and chronic infection.
Toxoplasmosis NAT-testing (PCR) from donor peripheral blood is not relevant, since negative PCR does not exclude relevant infection/parasitemia.
The transplant centre should be informed and clearance or deferral may be appropriate according to avidity test
2) Toxoplasmosis IgM = positive AND Toxoplasmosis IgG = negative
Further laboratory testing is necessary (e.g. Immunoblot/ISAGA) to verify if result is due to acute infection or non-specific binding.
No clearance should be given until clarification is obtained.
Justification for guidance
Toxoplasmosis is a recognised complication of immuno-suppression post-transplant.
References
APA Recommendations of the Center for International Blood and Marrow Transplant Research (CIBMTR®), the National Marrow Donor Program (NMDP), the European Blood and Marrow Transplant Group (EBMT), the American Society of Blood and Marrow Transplantation (ASBMT), the Canadian Blood and Marrow Transplant Group (CBMTG), the Infectious Disease Society of America (IDSA), the Society for Healthcare Epidemiology of America (SHEA), the Association of Medical Microbiology and Infectious Diseases Canada (AMMI), and the Centers for Disease Control and Prevention (CDC), Tomblyn, M., Chiller, T., Einsele, H., Gress, R., Sepkowitz, K., … Boeckh, M. A. (2009). Guidelines for Preventing Infectious Complications among Hematopoietic Cell Transplant Recipients: A Global Perspective. Biology of Blood and Marrow Transplantation : Journal of the American Society for Blood and Marrow Transplantation, 15(10), 1143–1238. doi:10.1016/j.bbmt.2009.06.019 [1]
[1]. Garweg, J.G., Peterson, E. (2020). Toxoplasmosis: Ocular disease. UpToDate. Retrieved October 18, 2023, from https://www.uptodate.com/contents/toxoplasmosis-ocular-disease?search=toxoplasmosis&source=search_result&selectedTitle=5~150&usage_type=default&display_rank=5#references
[2.] Khurana, S., & Batra, N. (2016). Toxoplasmosis in organ transplant recipients: Evaluation, implication, and prevention. Tropical parasitology, 6(2), 123–128. https://doi.org/10.4103/2229-5070.190814
Notes
Page created 7th March 2015