Early Detection of Toxoplasma Infection by Molecular Monitoring of Toxoplasma gondii in Peripheral Blood Samples after Allogeneic Stem Cell Transplantation

Abstract

Toxoplasmosis occurs more commonly after HSCT than has previously been suggested, and routine PCR testing of peripheral blood specimens may be an appropriate tool for guiding preemptive therapy in patients at very high risk of developing invasive disease.

Serological monitoring of a Toxoplasma infection after hematopoietic stem cell transplantation

“…Most cases of toxoplasmosis after HSCT are only diagnosed at autopsy because histological evidence of organ involvement is rarely obtained before death 6 . The early detection of T. gondii DNA in body fluids by PCR methods has been considered an important tool for monitoring Toxoplasma infection following HSCT 5,6 .…”

“…The early detection of T. gondii DNA in body fluids by PCR methods has been considered an important tool for monitoring Toxoplasma infection following HSCT 5,6 . A recent study has shown the importance of monitoring toxoplasmosis after HSCT with biological tests that combine PCR and serological techniques 3 .…”

Toxoplasmosis and allogeneic stem cell transplantation: can we do better?

“…It is higher in areas of endemicity, ranging from 6% in Europe [5,6] and 3% in Brazil [7] compared to 50.5% in USA [3,4] or Japan [8]. In one prospective study of seropositive allo-SCT recipients, 16% reactivated the infection over the first 6 months after transplant and 6% developed disease [6].…”

“…It is higher in areas of endemicity, ranging from 6% in Europe [5,6] and 3% in Brazil [7] compared to 50.5% in USA [3,4] or Japan [8]. In one prospective study of seropositive allo-SCT recipients, 16% reactivated the infection over the first 6 months after transplant and 6% developed disease [6]. As discussed by Cavattoni et al [1], diagnosis can be difficult due to the protean presentations of disease: with fever of unknown origin, neurological symptoms, pneumonitis, or myocarditis as well as disseminated infection with multisystem failure.…”

“…The highest risk patients are seropositive allo-SCT recipients who have received cord blood or unrelated donor transplant, T cell depleted transplants, previous alemtuzumab, who have GVHD, or are unable to take trimethoprim/sulphamethaxoazole (TMP/ SMX) Pneumocystis jiroveci prophylaxis [6,7], although toxoplasmosis occurs even in patients receiving TMP/SMX prophylaxis [3,7,8]. Almost half of the cases in one US center occurred in patients born outside of the USA [4].…”