Second unrelated bone marrow transplantation without additional conditioning therapy after engraftment failure

Imaging characteristics of toxoplasmosis encephalitis after bone marrow transplantation: report of two cases and review of the literature

Toxoplasmosis encephalitis is a severe, but often misdiagnosed complication in patients after bone marrow transplantation (BMT). We describe the unique computed tomography (CT) and magnetic resonance (MR) imaging features of cerebral toxoplasmosis in two bone marrow recipients and compare them to the cases in the literature. To our knowledge, this is the first report analyzing the appearance of cerebral toxoplasmosis on diffusion-weighted MR imaging (DWI).

Toxoplasmosis in bone marrow transplantation: a report of two cases and systematic review of the literature

Toxoplasma infection represents a rare but often fatal complication in bone marrow transplant (BMT) recipients. We report two cases of toxoplasmosis: one of successfully treated cerebral toxoplasmosis after peripheral blood stem cell transplantation, and a fatal case of pulmonary toxoplasmosis in a BMT recipient. We have systematically reviewed the 110 published cases of toxoplasmosis following BMT. We analyzed the pre-transplant and clinical features of BMT recipients developing toxoplasmosis, together with the diagnostic procedures used and treatment given. By univariate and multivariate statistical analysis we analyzed the risk factors for diagnosis (during life vs post-mortem) and Toxoplasma-related mortality. Ante-mortem diagnosis was made in 47% of cases. Site of infection (P = 0.02; odds ratio 10.8), presence of symptoms at onset (P = 0.01) and conditioning regimen (P = 0.04) were factors influencing whether the diagnosis was made before or after death. Overall mortality rate was 80% and that attributed to toxoplasmosis was 66%. Variables influencing outcome were: site of infection (P = 0.02; odds ratio 5.28), day of onset (P = 0.04) and conditioning regimen (P = 0.04). Underlying disease (P = 0.02; odds ratio 9.45), among patients diagnosed before death, was the most significant factor influencing outcome.

Disseminated toxoplasmosis after bone marrow transplantation: report of 9 cases

Toxoplasma infection following bone marrow transplantation (BMT) is infrequently reported. We report 9 cases of disseminated Toxoplasma gondii infection in BMT recipients documented during an 11-year period at our institution. The incidence of T. gondii infection in our institution (1.14 per 100 allogeneic BMT) is higher than previously reported. The most frequently affected sites were the brain, lungs, and heart. Findings common to most patients who developed toxoplasmosis were positive pre-transplant serology, allogeneic transplant and graft-versus-host disease and its treatment, as well as BMT from matched unrelated donors. All 9 patients died and 8 were diagnosed only after autopsy. Heightened awareness of the occurrence of toxoplasmosis in marrow recipients, especially in highly endemic areas, and early diagnosis and therapy are needed for a better outcome.

Prospective study of toxoplasma reactivation by polymerase chain reaction in allogeneic stem-cell transplant recipients

Toxoplasmosis is a rare but life-threatening complication of allogeneic stem-cell transplantation. Polymerase chain reaction (PCR) offers the possibility to make the diagnosis earlier than conventional techniques, and is then expected to improve the prognosis. We undertook a prospective screening using a competitive PCR in blood in 32 stem-cell transplant recipients. The sampling covered the first 150 days post-transplant, at days 21, 30, 45, 60, 90, 120, and 150. Twenty-four patients had anti-toxoplasma antibodies before transplant. Three of them (12.5%) had transient PCR-positive samples at 21, 45, and 90 days post-transplant, respectively. The three PCR-positive patients were febrile but had no funduscopic examination or cerebral computerised tomography (CT) scan abnormalities. The PCR signal disappeared when the patients were given trimethoprim-sulfamethoxazole, and no full-blown toxoplasmosis was observed. Toxoplasma reactivation evidenced using PCR is frequent in seropositive patients not receiving trimethoprim-sulfamethoxazole during the 1-3 months post-transplant. Toxoplasma PCR should be included in the diagnostic strategy of fever of unexplained origin in allogeneic stem-cell transplant recipients. Then, prompt specific therapy can be initiated to avoid development of full-blown toxoplasmosis.