Successful treatment of hemodynamic compromise caused by antibody-mediated and cellular rejection in a recipient 12 years after heart transplantation

Phase II clinical trial testing the safety of a humanised monoclonal antibody anti-CD20 in patients with heart failure with reduced ejection fraction, ICFEr-RITU2: study protocol

INTRODUCTION

Chronic heart failure with reduced ejection fraction (HFrEF) treatment targets neurohormonal inhibition; however, our experimental observations and the recent clinical evidence in myocardial infarction and heart transplant patients support the anti-inflammatory pathway as a potential novel therapeutic target. Therefore, we aimed to assess the safety of human monoclonal antibody-CD20 (rituximab) in patients with HFrEF.

METHODS AND ANALYSIS

We designed this protocol according to the Standard Protocol Items: Recommendations for Interventional Trials guidelines as a phase II, single-centred, single group and prospective clinical trial. We hypothesise that the use of a monoclonal antibody, rituximab, could be a potentially safe new agent in HFrEF management. We will include patients with EF≤40%, New York Heart Association functional class III/IV and unresponsive to standard treatment. We will use a dosing regimen (1000 mg) previously applied to post-transplant patients and patients with rheumatoid arthritis with favourable results, aiming to provide supplementary evidence of safety in patients with HFrEF. We designed strategies tailored to preserving the integrity of patient safety. The date of study initiation will be 29th of May 2019.

ETHICS AND DISSEMINATION

The following protocol was approved by IRB committees, and as a requirement, all patients need to sign an informed consent form before being subjected to any procedure prior to the initiation of the study. We are aware that the trial will be run in patients who due to their cardiovascular functional class, have reserved prognosis, with no known therapy that leads to improvement. Hence, this trial searches to establish the safety of an alternative strategy in ameliorating prognosis. Regardless of the study outcomes, whether favourable or not, they will be published. If a favourable outcome is evidenced, it will prompt performing a phase III, efficacy-based study.

TRIAL REGISTRATION NUMBER

The trial was approved by the IRB (CONBIOÉTICA-19-CEI-011-20161017 and COFEPRIS-17-CI-19-039-003), and registered at Clinicaltrials.gov (NCT03332888; Pre-Results).

Rituximab Therapy for Rejection in Pediatric Heart Transplant

OBJECTIVES

Humoral rejection is the B-cell-mediated production of immunoglobulin G antibody against the transplanted heart. Antibody-mediated rejection may be resistant to standard immunosuppressive therapy and is associated with high mortality and graft loss. Rituximab can be used to treat antibody-mediated rejection in heart transplant recipients. This retrospective study describes our experience with rituximab treatment in children with heart transplants.

MATERIALS AND METHODS

We present 7 pediatric patients with antibody-mediated rejection who were treated with plasma exchange and rituximab therapy. Rituximab was given at a dose of 375 mg/m2 by slow infusion in the intensive care unit after 5 days of plasmapheresis, in addition to a conventional regimen consisting of steroids, mycophenolate mofetil, and tacrolimus. The peripheral blood count and sodium, potassium, serum urea nitrogen, creatinine, aspartate aminotransferase, and alanine aminotransferase levels were measured in all patients before and after treatment.

RESULTS

Seven patients were treated with plasma exchange and rituximab. We repeated this therapy in 5 patients because of refractoriness or recurrent rejection. After diagnoses of antibody-mediated rejection, 4 patients died within 6 months (mortality rate of 57.1%). We did not observe any adverse effects or complications related to rituximab.

CONCLUSIONS

Rituximab can be used in humoral rejection after pediatric heart transplant. However, the success of the treatment is controversial, and further study is needed to find an effective treatment for antibody-mediated rejection and steroid-resistant cellular rejection in children.

Shoshin Beriberi With Low Cardiac Output and Hemodynamic Deterioration Treated Dramatically by Thiamine Administration

"Shoshin beriberi", which is a fulminant form of cardiovascular beriberi accompanied by hemodynamic deterioration with high cardiac output and decreased systemic blood pressure, caused by thiamine deficiency due to alcoholic abuse or malnutrition, is often difficult to address because of its rarity and non-specific symptoms. We here present a patient with a history of alcoholic abuse who had suffered hemodynamic deterioration with extremely low cardiac output refractory to extracorporeal membrane oxygenation and intravenous catecholamine support, which was improved dramatically by bolus intravenous thiamine administration. Such a type with low cardiac output would be the most severe form of Shoshin beriberi, and cannot be rescued without diagnostic administration of thiamine.

Late rejection occurred in recipients who experienced acute cellular rejection within the first year after heart transplantation

Serial endomyocardial biopsies (EMBs) are scheduled even several years after heart transplantation (HTx) to monitor for late rejection (LR). However, repeated EMBs are associated with an increased risk for fatal complications and decrease the quality of life of the recipient. We retrospectively analyzed clinical data from 42 adult recipients who had received HTx and were followed > 1 year at the University of Tokyo Hospital. Five recipients experienced LR at 1130 ± 157 days after HTx, and all 5 had experienced acute cellular rejection (ACR) with ISHLT grade ≥ 2R within the first year, which was treated with methylprednisolone pulse therapy (sensitivity, 1.000; specificity, 0.7027). Logistic regression analyses demonstrated that positive panel reactive antibody (PRA) was the only significant predictor for LR among all parameters at 1 year after HTx (P = 0.020, odds ratio 24.00). Among the 5 recipients with LR, LR occurred earlier in the two PRA positive recipients than in those with a negative PRA (981 ± 12 versus 1230 ± 110 days, P = 0.042). Among the perioperative parameters, gender mismatch [n = 13 (31%)] was the only significant predictor for ACR within the first year in logistic regression analyses (P = 0.042, odds ratio 4.200). In conclusion, the current schedule of serial EMBs should perhaps be reconsidered for recipients without any history of ACR within the first year due to their lower risk of LR.

Coincidence of cellular and antibody mediated rejection in heart transplant recipients - preliminary report

Antibody mediated rejection (AMR) can significantly influence the results of orthotopic heart transplantation (OHT). However, AMR and cellular rejection (CR) coexistence is poorly described. Therefore we performed a prospective pilot study to assess AMR/CR concomitance in endomyocardial biopsies (EMBs) obtained electively in 27 OHT recipients (21 M/6 F, 45.4 ± 14.4 y/o). Biopsy samples were paraffin embedded and processed typically with hematoxylin/eosin staining to assess CR, and, if a sufficient amount of material remained, treated with immunohistochemical methods to localize particles C3d and C4d as markers of antibody dependent complement activation. With this approach 80 EMBs, including 41 (51%) harvested within the first month after OHT, were qualified for the study. Among them 14 (18%) were C3d+, 37 (46%) were C4d+, and 12 (15%) were both C3d and C4d positive. At least one C3d+, C4d+, and C3d/C4d+ EMB was found in 10 (37%), 17 (63%), and 8 (30%) patients, respectively. Among 37 CR0 EMBs C3d was observed in 4 (11%), C4d in 17 (46%), and both C3d/C4d in 3 (8%) cases. Among 28 CR1 EMBs C3d was observed in 3 (11%), C4d in 11 (39%), and C3d/C4d in 3 (11%) cases. Among 15 CR2 EMBs C3d was observed in 7 (47%), C4d in 9 (60%), and C3d/C4d in 6 (40%) cases. Differences in C3d and C3d/C4d occurrence between grouped CR0-1 EMBs and CR2 EMBs (7/65 – 11% vs. 7/15 – 47%; 6/65 – 9% vs. 6/15 – 40%) were significant (p = 0.0035 and p = 0.0091, respectively, χ² test). In conclusion, apparently frequent CR and AMR coexistence demonstrated in this preliminary study warrants further investigation in this field.