Toxoplasmosis in cord blood transplantation recipients

Abstract

Toxoplasmosis is a devastating opportunistic infection that can affect immunocompromised patients such as cord blood transplantation (CBT) recipients. The clinical characteristics of 4 toxoplasmosis CBT patients treated at our institution are reviewed, together with 5 cases collected from the literature. The rate of toxoplasmosis in our hospital was 6% in CBT recipients and 0.2% in other types of allogeneic hematopoietic stem cell transplantation (P < 0.001). Five patients (56%) presented disseminated toxoplasmosis and 4 patients (44%) had localized infection in the central nervous system. In 5 of the 9 patients considered (56%), cytomegalovirus viral replication had been detected before the clinical onset of toxoplasmosis. Seven patients (78%) had previously developed graft-versus-host disease. All patients who exhibited disseminated disease died due to Toxoplasma infection. Pre-transplant serology was positive in 1 patient, negative in 3 patients, and not performed in another. Only 1 of these 5 patients with disseminated disease had received Toxoplasma prophylaxis with cotrimoxazole. It could be concluded that mortality in CBT patients with disseminated toxoplasmosis is unacceptably high. The negative results of serology in the majority of these cases, and its unspecific clinical presentation, makes diagnosis exceedingly difficult. Better diagnostic tests and prophylaxis strategy are needed in CBT recipients.

Toxoplasma gondii: How fatal is it in pediatric allogeneic bone marrow transplantation setting?

“…Cord blood transplantation, antithymocyte globulin in the conditioning regimen, CMV replication before the onset of toxoplasmosis or irradiation which impairs the recipient's immune response have been implicated as the main risk factors for toxoplasmosis in HSCT recipients. Two of our patients received irradiation pre‐transplant and ATG in the conditioning regimen, while the second one had CMV reactivation before manifestation of toxoplasmosis symptoms and other viruses reactivations, all with CNS involvement, which was fatal for the patient …”

“…In fact, the first case with the disseminated toxoplasmosis had a very high titer of toxoplasma IgG antibodies before transplantation. Bone marrow recipients who are seronegative are at very low risk of acquiring toxoplasmosis, although they can be infected through undercooked meat or raw vegetables . Additionally, all of our patients had GVHD requiring steroids before the onset of toxoplasma infection but it should be highlighted that the third patient did not receive any corticosteroids for at least three months before toxoplasma gondii infection.…”

Toxoplasma prophylaxis in haematopoietic cell transplant recipients

“…In one retrospective study, implementation of preengraftment azithromycin followed by pyrimethamine/suladoxine led to a decrease in toxoplasmosis in cord blood HCT from a historical three (15%) cases in 20 cord blood HCT to one (2%) case in 50 cord blood HCT (P ¼ 0.067) [45]. Because of limited experience and reports of failure, they should not be used as firstline agents.…”

Skin nodules in a patient with acute lymphoblastic leukaemia

“…Toxoplasmosis occurs mainly in pretransplant seropositive recipients and only a few cases have been reported in seronegative patients 16. Risk factors are positive pretransplant serology, GVHD, TBI in the conditioning regimen or T-cell depletion.…”