Disseminated toxoplasmosis presenting as septic shock five weeks after renal transplantation

Serological Responses to Toxoplasma gondii and Matrix Antigen 1 Predict the Risk of Subsequent Toxoplasmic Encephalitis in People Living with HIV

BACKGROUND

Clinically useful predictors for fatal toxoplasmosis are lacking. We investigated the value of serological assays for antibodies to whole Toxoplasma antigens and to peptide antigens of the Toxoplasma cyst protein MAG1, for predicting incident toxoplasmic encephalitis (TE) in people living with HIV (PLWH).

METHODS

We performed a nested case control study, conducted within the Multicenter AIDS Cohort Study (MACS), using serum samples obtained 2 years prior to diagnosis of TE from 28 cases, and 37 HIV disease-matched Toxoplasma seropositive controls at matched time-points. Sera were tested for Toxoplasma antibodies using a commercial assay and for antibodies to MAG1_4.2 and MAG1_5.2 peptides in ELISA.

RESULTS

Two years prior to clinical diagnosis, 68% of TE cases were MAG1_4.2 seropositive compared with 16% of controls (OR 25.0, 95% CI 3.14-199.18). Corresponding results for MAG1_5.2 seropositivity were 36% and 14% (OR 3.6, 95% CI 0.95-13.42). Higher levels of antibody to MAG1_4.2 (OR 18.5 per doubling of the OD value, 95% CI 1.41-242) and to Toxoplasma (OR 2.91 for each OD unit increase, 95% CI 1.48-5.72) were also associated with the risk of TE. When seropositivity was defined as the presence of MAG1 antibody or relatively high levels of Toxoplasma antibody, the sensitivity was 89% and specificity was 68% for subsequent TE.

CONCLUSIONS

Antibodies to MAG1 showed predictive value on the occurrence of TE in PLWH, and the predictive performance was further improved by adding the levels of Toxoplasma antibody. These measures could be clinically useful for predicting subsequent diseases in multiple at-risk populations.

Toxoplasmosis after allogeneic haematopoietic cell transplantation-disease burden and approaches to diagnosis, prevention and management in adults and children

BACKGROUND

Toxoplasmosis is a rare but highly lethal opportunistic infection after allogeneic haematopoietic cell transplantation (HCT). Successful management depends on screening, early recognition and effective treatment.

OBJECTIVES

To review the current epidemiology and approaches to diagnosis, prevention and treatment of toxoplasmosis in adult and paediatric allogeneic HCT recipients.

SOURCE

Search of the English literature published in MEDLINE up to 30 June 2020 using combinations of broad search terms including toxoplasmosis, transplantation, diagnosis, epidemiology, prevention and treatment. Selection of articles for review and synthesis on the basis of perceived quality and relevance of content.

CONTENT

Toxoplasmosis continues to be a major challenge in the management of allogeneic HCT recipients. Here we provide a summary of published case series of toxoplasmosis in adult and paediatric patients post allogeneic HCT. We review and discuss the pathogenesis, epidemiology, clinical presentation, diagnosis and current recommendations for prevention and treatment. We also discuss impacts of toxoplasmosis in this setting and factors affecting outcome, emphasizing attention to neurological, neuropsychological and neurocognitive late effects in survivors.

IMPLICATIONS

Apart from careful adherence to established strategies of disease prevention through avoidance of primary infection, identification of seropositive patients and implementation of molecular monitoring, future perspectives to improve the control of toxoplasmosis in allogeneic HCT recipients may include the systematic investigation of pre-emptive treatment, development of immunomodulatory approaches, antimicrobial agents with activity against the cyst form and vaccines to prevent chronic infection.

Disseminated toxoplasmosis associated with hemophagocytic syndrome after kidney transplantation: A case report and review

Disseminated toxoplasmosis is infrequent after kidney transplant transmission but life-threatening because of a lack of diagnostic suspicion as well as specific chemoprophylaxis recommendations. Solid organ transplantation has resulted in few cases of disseminated toxoplasmosis presenting with associated hemophagocytic syndrome. Herein, we report, within the context of a donor/receiver mismatch, a case of a toxoplasmosis associated with hemophagocytic syndrome in a kidney transplant recipient. Molecular and serological investigations confirmed Toxoplasma gondii transmission through the kidney graft.

Toxoplasmosis in the non-orthotopic heart transplant recipient population, how common is it? Any indication for prophylaxis?

PURPOSE OF REVIEW

Unlike in orthotopic heart transplant (OHT) setting where toxoplasma prophylaxis is a standard practice in pretransplant toxoplasma seronegative recipients who have received donor hearts from seropositive donors (D+/R-), there is no consensus regarding prophylaxis in non-OHT recipients.

RECENT FINDINGS

The incidence of toxoplasma disease in non-OHT recipients is less than 1% but its true burden is underestimated. Among 31 cases of toxoplasma disease reported from 2004 through 2017, renal and liver transplant recipients comprised of 90% of cases. A total of 94% of 18 recipients with known pretransplant serology were seronegative recipients (mostly D+/R-). Out of 16 recipients with adequate information, 10 (63%) and five (31%) were deemed to be donor derived and nondonor-derived primary toxoplasmosis respectively. Tissue invasive reactivation was uncommon. Almost all cases were described in patients not on prophylaxis at the time of presentation. Universal screening of donor/recipient toxoplasma serology for risk stratification is beneficial as illustrated by reports of fatal cases of toxoplasmosis due to unavailability of positive donor serology results.

SUMMARY

Toxoplasma disease in non-OHT predominantly occurs in pretransplant seronegative recipients- mostly in D+/R- group and is rare in seropositive recipients. Posttransplant prophylaxis should be targeted against the high-risk D+/R- group and should be considered in seropositive recipients in whom unusually high immunosuppression is implemented. Toxoplasma serologies and PCR should be used in combination for the diagnosis of toxoplasmosis in non-OHT patients.

Toxoplasmosis in Transplant Recipients, Europe, 2010-2014

Transplantation activity is increasing, leading to a growing number of patients at risk for toxoplasmosis. We reviewed toxoplasmosis prevention practices, prevalence, and outcomes for hematopoietic stem cell transplant (HSCT) and solid organ transplant (SOT; heart, kidney, or liver) patients in Europe. We collected electronic data on the transplant population and prevention guidelines/regulations and clinical data on toxoplasmosis cases diagnosed during 2010–2014. Serologic pretransplant screening of allo-hematopoietic stem cell donors was performed in 80% of countries, screening of organ donors in 100%. SOT recipients were systematically screened in 6 countries. Targeted anti-Toxoplasma chemoprophylaxis was heterogeneous. A total of 87 toxoplasmosis cases were recorded (58 allo-HSCTs, 29 SOTs). The 6-month survival rate was lower among Toxoplasma-seropositive recipients and among allo-hematopoietic stem cell and liver recipients. Chemoprophylaxis improved outcomes for SOT recipients. Toxoplasmosis remains associated with high mortality rates among transplant recipients. Guidelines are urgently needed to standardize prophylactic regimens and optimize patient management.

Advances and Challenges in Understanding Cerebral Toxoplasmosis

Toxoplasma gondii is a widespread parasitic pathogen that infects over one third of the global human population. The parasite invades and chronically persists in the central nervous system (CNS) of the infected host. Parasite spread and persistence is intimately linked to an ensuing immune response, which does not only limit parasite-induced damage but also may facilitate dissemination and induce parasite-associated immunopathology. Here, we discuss various aspects of toxoplasmosis where knowledge is scarce or controversial and, the recent advances in the understanding of the delicate interplay of T. gondii with the immune system in experimental and clinical settings. This includes mechanisms for parasite passage from the circulation into the brain parenchyma across the blood-brain barrier during primary acute infection. Later, as chronic latent infection sets in with control of the parasite in the brain parenchyma, the roles of the inflammatory response and of immune cell responses in this phase of the disease are discussed. Additionally, the function of brain resident cell populations is delineated, i.e., how neurons, astrocytes and microglia serve both as target cells for the parasite but also actively contribute to the immune response. As the infection can reactivate in the CNS of immune-compromised individuals, we bring up the immunopathogenesis of reactivated toxoplasmosis, including the special case of congenital CNS manifestations. The relevance, advantages and limitations of rodent infection models for the understanding of human cerebral toxoplasmosis are discussed. Finally, this review pinpoints questions that may represent challenges to experimental and clinical science with respect to improved diagnostics, pharmacological treatments and immunotherapies.

Solid Organ Transplant and Parasitic Diseases: A Review of the Clinical Cases in the Last Two Decades

The aim of this study was to evaluate the occurrence of parasitic infections in solid organ transplant (SOT) recipients. We conducted a systematic review of literature records on post-transplant parasitic infections, published from 1996 to 2016 and available on PubMed database, focusing only on parasitic infections acquired after SOT. The methods and findings of the present review have been presented based on the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) checklist. From data published in the literature, the real burden of parasitic infections among SOT recipients cannot really be estimated. Nevertheless, publications on the matter are on the increase, probably due to more than one reason: (i) the increasing number of patients transplanted and then treated with immunosuppressive agents; (ii) the “population shift” resulting from immigration and travels to endemic areas, and (iii) the increased attention directed to diagnosis/notification/publication of cases. Considering parasitic infections as emerging and potentially serious in their evolution, additional strategies for the prevention, careful screening and follow-up, with a high level of awareness, identification, and pre-emptive therapy are needed in transplant recipients.