Toxoplasmosis in Bone Marrow-Transplant Recipients: Report of Seven Cases and Review

Abstract

We report seven cases of cerebral or disseminated toxoplasmosis that occurred following bone marrow transplantation (BMT) and review the other 24 cases described in the literature. For all the cases, toxoplasmosis occurred within 6 months of BMT, with the highest incidence in the second and third months. Twenty-four of 26 recipients tested serologically before BMT were positive for Toxoplasma gondii, a finding that supports the view that such cases result from reactivation of latent infection. At the onset of clinical symptoms, IgG antibody titers were unchanged or decreased in 23 of 25 documented cases, and IgM antibodies were detected in two cases. Antemortem diagnosis was made in 16 cases and was based on the response to specific therapy in six cases and/or the demonstration of the parasite in body fluids or tissues in 10 cases. Autopsy was performed in 19 cases and revealed that infection was not restricted to the brain but either involved lung or heart tissue or was disseminated in 14 cases.

Toxoplasma retinitis/encephalitis 9 months after allogeneic bone marrow transplantation

“…2 In the present case, PCR and antibody analysis of CSF and CT scanning of the cerebrum initially failed to give a diagnosis of toxoplasmosis, but PCR and antibody analysis of the ACF, together with MRI scanning of the cerebrum, appeared to be of an important additional support, as has been discussed earlier. 4 The role of PCR was controversial in our case.…”

“…[1][2][3] Retinitis has been described in only two other cases 7,8 and as in the present case can have a rather late onset post-BMT; in one case retinitis developed 161 days post-BMT, 7 in the other after 9 months. 8 In presenting this case we emphasize the possibility of toxoplasma retinitis as a very late disease manifestation in BMT recipients.…”

“…5,6 The incidence of reactivated toxoplasmosis in BMT patients has been calculated to be 2% in BMT patients who have a positive serostatus for toxoplasmosis pre-BMT. 2,3 In our own series of 415 allogeneic BMT patients, (179(43%) were toxoplasma IgG seropositive pre-BMT) we have encountered two other patients with a post-mortem diagnosis of toxoplasma encephalitis, giving a total incidence of 1.6% in seropositive recipients. Next to a positive serostatus pre-BMT, severe GVHD combined with intensified immunosuppression and negative serostatus of the donor are established risk factors for toxoplasma reactivation; [1][2][3] all were present in our patient.…”

“…2,3 In our own series of 415 allogeneic BMT patients, (179(43%) were toxoplasma IgG seropositive pre-BMT) we have encountered two other patients with a post-mortem diagnosis of toxoplasma encephalitis, giving a total incidence of 1.6% in seropositive recipients. Next to a positive serostatus pre-BMT, severe GVHD combined with intensified immunosuppression and negative serostatus of the donor are established risk factors for toxoplasma reactivation; [1][2][3] all were present in our patient. Trimethoprim-sulphamethoxazole is generally believed to protect against toxoplasma reactivation in immunocompromised hosts and the fact that our patient received this prophylactic drug for only a short period of time might have been an additional risk factor in this case.…”

“…Its occurrence has only occasionally been described in immunodeficient patients not being related to AIDS. 1 The number of reported cases in bone marrow transplant (BMT) recipients does not exceed 50 [1][2][3] and in nearly all cases the infection occurred within 6 months after transplantation. 2,3 …”