Toxoplasma gondii serostatus is not associated with impaired long-term survival after heart transplantation

Pre-Transplant Seroprevalence, Associated Factors, and Post-Transplant Incidence of Toxoplasma gondii Infection Among Heart Transplant Recipients in Japan

BACKGROUND

Among solid organ transplant (SOT) recipients, heart transplant (HT) recipients are at a higher risk of Toxoplasma gondii infection. As Toxoplasma seroprevalence varies by geographic location, updated local epidemiology is essential to guide preventive and therapeutic strategies. However, the Toxoplasma seroprevalence and incidence of post-transplant toxoplasmosis among SOT recipients in Japan are unknown.

METHODS

We performed a single-center retrospective observational study at an HT center in Tokyo, Japan. All HT recipients aged ≥18 years between 2006 and April 2019 were included. We reviewed patient charts and conducted a questionnaire survey to investigate the risk factors for infection.

RESULTS

Among 105 recipients included in the study, 11 (10.5%) were seropositive before transplant. Ninety-five recipients (90.5%), including all pre-transplant seropositive recipients, answered the questionnaire. The recipients who had lived in Okinawa (odds ratio [OR] 7.5 [95% CI 1.42-39.61]; P = .032) and who reported raw-meat eating habits (OR 4.64 [95% CI 1.04-23.3]; P = .021) were more likely to be seropositive. None of the patients developed symptoms of toxoplasmosis. The post-transplant incidence of other major adverse outcomes was not significantly different according to the pre-transplant serostatus.

CONCLUSIONS

About 10% of HT recipients at an HT center in Tokyo were seropositive for Toxoplasma pre-transplant, and none developed symptomatic toxoplasmosis post-transplant on trimethoprim-sulfamethoxazole. The history of raw meat consumption was associated with seropositivity; therefore, avoiding it might be recommended for HT recipient candidates.

Comparison of serologic status of Toxoplasma gondii infection in pre- and post-heart transplantation in a pediatric population: A preliminary study

BACKGROUND

Toxoplasmosis is an important opportunistic infection in immunocompromised children, especially in heart transplant recipients. This study aimed to investigate pre- and post-transplant serology for toxoplasmosis along with post-transplant PCR in pediatric heart transplant patients.

METHODS

This cross-sectional study was performed on 38 heart transplant recipients aged 1-17 years, by the end of 2018. Pre- and post-transplant IgM and IgG titrations were measured using ELISA method. Nested PCR of B1 gene was performed to identify Toxoplasma gondii (T gondii) infection after transplant.

RESULTS

Totally, 11.4% of patients had positive IgG and 91.4% had negative IgM for toxoplasmosis before heart transplantation. The mean of pre-transplant IgG titration for seropositive and seronegative patients was 22.32 ± 15.30 IU/mL and 1.49 ± 1.15 IU/mL, respectively (P < .001). All cases were on chemoprophylaxis with trimethoprim-sulfamethoxazole (TMP/SMX). The mean of post-transplant IgG titration was 1.62 ± 1.87 IU/mL, which was negative for all cases. Investigating pre-transplant, IgM titration, 5.7% were positive, 91.4% were negative, and 2.9% were borderline. All cases were post-transplant IgM negative. The mean of post-transplant IgG titrations was significantly higher in the first 6 months (3.26 ± 2.68 IU/mL) compared to 6-12 (1.30 ± 1.34 IU/mL; P = .039) and > 12 months (1.07 ± 1.27 IU/mL; P = .004) time periods. The result of PCR for B1 gene in all cases was negative.

CONCLUSIONS

Chemoprophylaxis with TMP/SMX seems to be effective in prevention of T gondii infection or reactivation among pediatric heart transplantation population. Anti-T. gondii-IgG level alone may not be sensitive enough for evaluation of the infection at least after 6 months post-transplantation.

Review of the impact of donor characteristics on pediatric heart transplant outcomes

Heart transplantation (HTx) is a treatment option for end-stage heart failure in children. HTx is limited by the availability and acceptability of donor hearts. Refusal of donor hearts has been reported to be common with reasons for refusal including preexisting donor characteristics. This review will focus on the impact of donor characteristics and comorbidities on outcomes following pediatric HTx. A literature review was performed to identify articles on donor characteristics and comorbidities and pediatric HTx outcomes. There are many donor characteristics to consider when accepting a donor heart. Weight-based matching is the most common form of matching in pediatric HTx with a donor-recipient weight ratio between 0.7 and 3 having limited impact on outcomes. From an age perspective, donors <50 years can be carefully considered, but the impact of ischemic time needs to be understood. To increase the donor pool, with minimal impact on outcomes, ABO-incompatible donors should be considered in patients that are eligible. Other factors to be considered when accepting an organ is donor comorbidities. Little is known about donor comorbidities in pediatric HTx, with most of the data available focusing on infections. Being aware of the potential infections in the donor, understanding the testing available and risks of transmission, and treatment options for the recipient is essential. There are a number of donor characteristics that potentially impact outcomes following pediatric HTx, but these need to be taken into consideration along with their interactions with recipient factors when interpreting the outcomes following HTx.

Tissue and blood protozoa including toxoplasmosis, Chagas disease, leishmaniasis, Babesia, Acanthamoeba, Balamuthia, and Naegleria in solid organ transplant recipients- Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention, and management of tissue and blood protozoal infections in the pre- and post-transplant period. Significant new developments in the field have made it necessary to divide the previous single guideline published in 2013 into two sections, with the intestinal parasites separated from this guideline devoted to tissue and blood protozoa. The current update reflects the increased focus on donor screening and risk-based recipient monitoring for parasitic infections. Increased donor testing has led to new recommendations for recipient management of Toxoplasma gondii and Trypanosoma cruzi. Molecular diagnostics have impacted the field, with access to rapid diagnostic testing for malaria and polymerase chain reaction testing for Leishmania. Changes in Babesia treatment regimens in the immunocompromised host are outlined. The risk of donor transmission of free-living amebae infection is reviewed. Changing immigration patterns and the expansion of transplant medicine in developing countries has contributed to the recognition of parasitic infections as an important threat to transplant outcomes. Medications such as benznidazole and miltefosine are now available to US prescribers as access to treatment of tissue and blood protozoa is increasingly prioritized.

Predictors of 1-year mortality in heart transplant recipients: a systematic review and meta-analysis

Objective

A systematic summary of the observational studies informing heart transplant guideline recommendations for selection of candidates and donors has thus far been unavailable. We performed a meta-analysis to better understand the impact of such known risk factors.

Methods

We systematically searched and meta-analysed the association between known pretransplant factor and 1-year mortality identified by multivariable regression models. Our review used the Grading of Recommendations, Assessment, Development and Evaluation for assessing the quality of assessment. We pooled risk estimates by using random effects models.

Results

Recipient variables including age (HR 1.16 per 10-year increase, 95% CI 1.10–1.22, high quality), congenital aetiology (HR 2.35, 95% CI 1.62 to 3.41, moderate quality), diabetes (HR 1.37, 95% CI 1.15 to 1.62, high quality), creatinine (HR 1.11 per 1 mg/dL increase, 95% CI 1.06 to 1.16, high quality), mechanical ventilation (HR 2.46, 95% CI 1.48 to 4.09, low quality) and short-term mechanical circulatory support (MCS) (HR 2.47, 95% CI 1.04 to 5.87, low quality) were significantly associated with 1-year mortality. Donor age (HR 1.20 per 10-year increase, 95% CI 1.14 to 1.26, high quality) and female donor to male recipient sex mismatch (HR 1.38, 95% CI 1.06 to 1.80, high quality) were significantly associated with 1-year mortality. None of the operative factors proved significant predictors.

Conclusion

High-quality and moderate-quality evidence demonstrates that recipient age, congenital aetiology, creatinine, pulsatile MCS, donor age and female donor to male recipient sex mismatch are associated with 1-year mortality post heart transplant. The results of this study should inform future guideline and predictive model development.

Toxoplasma Gondii Serostatus in Heart Transplant Recipients: Is It an Independent Prognostic Factor?

INTRODUCTION AND OBJECTIVES

To assess the potential association between recipient Toxoplasma gondii serostatus and outcomes after heart transplant (HT).

METHODS

We conducted a retrospective single-center study of 657 HT recipients from 1991 to 2015. Survival and the incidence of adverse clinical events of T. gondii-seropositive (n = 481) vs T. gondii-seronegative (n = 176) recipients were compared by means of 2 different multivariable Cox regression models. Model 1 included solely age and sex, and model 2 included other potential confounders.

RESULTS

Over a median follow-up of 2903 days (interquartile range: 898-4757), 250 seropositive recipients (52%) and 72 seronegative recipients (41%) died. Univariable analysis showed increased posttransplant mortality among T. gondii-seropositive recipients (hazard ratio [HR] = 1.31; 95% confidence interval [95%CI], 1,00-1.70). After multivariable adjustment, the statistical significance of this association was lost (model 1: HR = 1.09; 95%CI, 0.83-1.43; model 2:HR = 1.12; 95%CI, 0.85-1.47). Recipient T. gondii seropositivity was independently associated with an increased risk of acute rejection (model 1: HR = 1.36; 95%CI, 1.06-1.74; model 2: HR = 1.29; 95%CI, 1.01-1.66). Multivariable models showed no statistically significant impact of recipient T. gondii serostatus on the incidence of infection, malignancy, coronary allograft vasculopathy, or the composite outcome of cardiac death or retransplant. No significant association was found between donor-recipient T. gondii serostatus matching and posttransplant outcome.

CONCLUSIONS

In this study, recipient T. gondii serostatus was not an independent predictor of long-term post-HT outcome.

Improved long-term survival in Dutch heart transplant patients despite increasing donor age: the Rotterdam experience

Over the past decades donor and recipient characteristics and medical management of heart transplantation (HT) patients have changed markedly. We studied the impact of these changes on long-term clinical outcome. Data of all consecutive HT recipients in our center have been collected prospectively. Cohort A (n = 353) was defined as the adult pts transplanted between 1984 and 1999 and was compared with cohort B (n = 227) transplanted between 2000 and 2013. Compared with cohort A, recipients in cohort B had older donors (mean age 29 vs. 43 years, donors aged >50 year: 2% vs. 33%, respectively). Survival at 1 and 10 years in cohort A vs. B was 89% vs. 86% and 53% vs. 68%, respectively (P = 0.02). Cohort B pts were treated more often with tacrolimus-based immunosuppression (77% vs. 22%; P = <0.0001) and early statins post-HT (88% vs. 18%; P = 0.0001), while renal function was better conserved at 5 and 10 years (P = 0.001 and 0.02). Multivariate analysis showed significant reduction in 10-year mortality with tacrolimus-based immunosuppression (HR 0.27 and 95% CI 0.17-0.42), hypertension post-HT (HR 0.5, 95% CI 0.36-0.72), and revascularization (HR 0.28, 95% CI 0.15-0.52). In spite of the use of much older donors, the long-term outcome after HT has improved considerably in the last decade, probably due to the introduction of newer treatment modalities.

Toxoplasma gondii Serology and Outcomes After Heart Transplantation: Contention in the Literature

BACKGROUND

Toxoplasma gondii is an endemic pathogen to which approximately half of healthy patients develop antibodies. Toxoplasma serology is routinely assessed prior to heart transplantation. It has been suggested that donor or recipient toxoplasma serologic status may be associated with poor long-term outcomes post-transplantation, but current literature reveals conflicting results.

METHODS

From 1995 to 2012 at our single center, we retrospectively reviewed 785 heart transplant patients for pre-transplantation T. gondii serology. Patients were divided into T. gondii seronegative and seropositive groups. Subgroups in each group were created based on whether the donor was seropositive or seronegative. We assessed survival, freedom from nonfatal major adverse cardiac events, and freedom from cardiac allograft vasculopathy at 5 years post-transplantation.

RESULTS

No significant difference was found between 5-year outcomes of pre-transplant T. gondii seronegative and T. gondii seropositive recipients post-heart transplantation. However, in the donor-seropositive/recipient-seronegative subgroup (D+/R-), there was a significantly lower 5-year survival rate compared to the cohort of donor-seronegative/recipient-seronegative (D-/R-) patients (60% vs 87%, P = .04). After adjustment by multivariate analysis, D+/R- status conferred a trend towards increased mortality (HR 3.0, P = .06).

CONCLUSIONS

Toxoplasma serology prior to heart transplantation does not appear to impact post-transplantation outcome. However, toxoplasma seronegative patients who receive toxoplasma seropositive hearts appear to have poorer 5-year survival compared to toxoplasma seronegative patients who received toxoplasma seronegative hearts. Due to the small sample size, the association between T. gondii serology mismatch and long-term survival warrants further study.