Efficacy and Safety of mRNA SARS-CoV2 Vaccination in Heart Transplant Recipients

Purpose

Data on immunologic response to SARS-CoV2 vaccination in heart transplant recipients are scarce. We investigated the efficacy and safety of mRNA SARS-CoV2 vaccination in this patient population.

Methods

In a retrospective single-center study we included 54 consecutive adult heart transplant recipients who received 2 doses of mRNA SARS-CoV2 vaccine between January 1 and June 30, 2021. All patients were followed for 112±28 days after the second dose. At the end of follow-up we measured humoral response to SARS-CoV2 by assessing total antibody levels to the receptor-binding domain of SARS-CoV2 spike (S) protein using anti-RBD immunoassay. Anti-S antibody serum levels ≥250 BAU/mL were considered protective. At the same time, cellular response was measured by the IFN-γ response to S-peptide stimulation of recipient T lymphocyte populations. Protective cellular response was defined as more than 0,3% of IFN-γ responsive T cells.

Results

Of 54 recipients, 44 (81%) were male with a mean age of 63±8 years and a mean time from transplantation of 6.6±4.0 years. Immunosupressive regimen consisted of tacrolimus (mean C0 level 7.4±1.7 μg/mL), mycophenolate mofetil (mean dose 2120±419 mg) and steroids (mean dose 2.5±0.9 mg). The majority of patients received BTN162b2 vaccine (83%), and 17% of recipients were vaccinated with mRNA-1273. During follow-up, a humoral response was present in 24 (44%) of the recipients (median anti-S serum level 35.5 BAU/mL). We found no difference in humoral response between patients receiving BNT162b2 and mRNA-1273 vaccine (median anti-S serum level 68.3 BAU/mL vs. 15.5 BAU/mL, P=0.81). Protective humoral response was observed in 6 (11%) of the recipients (median anti-S serum level 557 BAU/mL). A cellular response to vaccine was present in 3 (6%) of the recipients; all 3 displayed a protective level of reponse. No recipients developed simultaneous protective humoral and cellular responses. Recipient age was the only predictor of protective humoral response (55±11 years in responders vs. 65±8 years in nonresponders; P=0.01). In 3 (6%) recipients we found worsening of allograft function requiring hospital admission, which occured within 1 month after receiving the second dose of vaccine.

Conclusion

In heart transplant recipients, mRNA SARS-CoV2 vaccination appears to be of limited efficacy and may, in some cases, be associated with worsening of allograft function.

CD34+ enriched cell products intended for autologous transendocardial CD34+ cell transplantation release significant amounts of angiopoietin-1

OBJECTIVES

Cell-based therapy has emerged as a promising strategy for the treatment of patients with heart failure. Increasing evidence supports the hypothesis that paracrine mechanisms mediated by soluble factors released by the cells play a predominate role in reparative processes. The aim of our study was to analyze which cytokines are released by CD34⁺ enriched cell products intended for autologous transendocardial CD34⁺ cell transplantation in patients with cardiomyopathy.

MATERIAL AND METHODS

The peripheral blood CD34⁺ cells from 12 patients were mobilized with granulocyte colony-stimulating factor, collected via apheresis and enriched by immunoselection.

RESULTS

In CD34⁺ enriched cell population, hematopoietic, but not mesenchymal or endothelial, progenitors were detected. Except for angiopoietin-1, other measured cytokines (FGF1, FGF2, VEGF, PDGF, IL-6, HGH, SDF-1α/CXCL12, NRG1) were not released by CD34⁺ cells. The average concentration of angiopoietin-1 released by 5×10⁶ CD34⁺ cells grown in neutral DMEM medium was 213.6±130.0pg/mL (range: 74-448pg/mL). Angiopoietin-1 secretion correlated well with CD34⁺ cell's capacity for generating colonies derived from hematopoietic progenitors (Pearson's correlation=0.964; P<0.001).

CONCLUSION

Our study presents angiopoietin-1 as an interesting candidate and suggests future studies to explore how its release by CD34⁺ cells might impact the success of autologous CD34⁺ cell transplantation.

Granulocyte colony-stimulating factor therapy is associated with a reduced incidence of acute rejection episodes or allograft vasculopathy in heart transplant recipients

BACKGROUND

We evaluated the potential effects of granulocyte colony-simulating factor (G- CSF) on the incidence of rejection and allograft vasculopathy in heart transplant recipients.

METHODS

Of 247 patients undergoing heart transplantation from 2000 to 2007, 52 (21%) developed leukopenia (white blood cell [WBC] <2.5 × 10(9) cells/L) in the absence of active infection, rejection, or malignancy. In 24 (46%) patients a clinical decision was made to treat the leukopenia with G-CSF (G-CSF group), and 28 (54%) Patients received no G-CSF (non-GCSF group). Patients followed up for 1 year after the period of leukopenia were assessed for allograft vasculopathy and acute rejection incidence.

RESULTS

At baseline, the G-CSF group and the non-GCSF group did not differ in age, gender, race, heart failure etiology, creatinine, left ventricular ejection fraction (LVEF) or immunosupressive regimen. During 1-year follow-up there were no deaths in the G-CSF group, and 1 death in the non-GCSF group (P = .34). The incidence of rejection or progressive allograft vasculopathy was lower in the G-CSF group when compared with the non-GCSF group (2 [8%] vs 15 [53%]; P < .01). Multivariate analysis identified both prior rejection episodes and G-CSF therapy as factors associated with the combined end-point of rejection or progressive allograft vasculopathy (odds ratio [OR] = 7.89 [1.67-37.2] and OR = 0.09 [0.02-0.52], respectively).

CONCLUSIONS

G-CSF therapy appears to be associated with a decreased incidence of acute rejection episodes or allograft vasculopathy in heart transplant recipients, suggesting a potential immunomodulatory effect of G-CSF.

CD34+ stem cell therapy in nonischemic dilated cardiomyopathy patients

Recent trends indicate that patients with nonischemic dilated cardiomyopathy represent the largest subpopulation of heart failure patients with a significant need for alternative treatment modalities. Similar to patients with ischemic cardiomyopathy, patients with nonischemic dilated cardiomyopathy have been found to have myocardial regions with flow abnormalities, which may represent targets for neoangiogenic therapies. CD34(+) stem cells might contribute to the formation of new blood vessels from existing vascular structures in ischemic tissues by the direct incorporation of injected cells into the newly developing vasculature or by the production and secretion of angiogenic cytokines. This review summarizes the long-term clinical effects and potential underlying mechanisms of CD34(+) cell therapy in patients with nonischemic dilated cardiomyopathy.

Testosterone-related shortening of QTc interval in women with polycystic ovary syndrome

CONTEXT

The presence of several cardiovascular risk factors is observed in women with polycystic ovary syndrome (PCOS). On the other hand, the QTc interval duration, which is related to cardiac arrhythmia and sudden death, has not been investigated thoroughly in PCOS population.

OBJECTIVE

To investigate QTc interval duration and its relation to testosterone in women with PCOS.

DESIGN

Cross sectional case-control study.

SETTING

Outpatient setting, tertiary university medical centre.

PATIENTS

We enrolled 119 consecutive patients in whom PCOS was diagnosed based on oligomenorrhea, infertility (>2 yr), ineffective ovarian stimulation, and ultrasonographic criteria. The control group (controls) included 64 age-matched healthy women without clinical or laboratory evidence of PCOS.

INTERVENTIONS

In all participants we measured QTc interval duration on a standard electrocardiogram and determined plasma levels of high sensitivity C-reactive protein (hsCRP), endothelin-1 (ET-1), insulin, and testosterone.

MAIN OUTCOME MEASURE

Shorter QTc interval duration in PCOS patients.

RESULTS

When compared to controls, PCOS patients displayed higher values of hsCRP (2.35+/-2.14 mg/l vs 1.18+/-1.24 mg/l; p=0.01), ET-1 (23.6+/-10.3 ng/l vs 12.9+/-20.7 ng/l; p=0.03), insulin (18.5+/-7.8 mIU/l vs 10.7+/-9.1 mIU/l; p=0.02), and testosterone (2.7+/-2.1 nmol/l vs 1.4+/-1.7 nmol/l; p=0.01). QTc interval in PCOS patients was significantly shorter than in controls (401+/-61 msec vs 467+/-61 msec; p=0.007), and inversely related to the plasma levels of testosterone (Spearman -0.45, p=0.005).

CONCLUSIONS

QTc interval in PCOS patients is short, and inversely associated with increased levels of testosterone. QTc interval duration is not part of an adverse cardiac risk profile in PCOS.

Metabolic and cardiovascular changes in women with polycystic ovary syndrome

OBJECTIVE

To analyze the relationship between QTc interval and cardiovascular risk factors in women with polycystic ovary syndrome (PCOS).

METHODS

Study group included 119 PCOS women (age: 32.2+/-5.2 years) and the control group 64 age-matched healthy women; they all underwent QT interval measurement, and plasma levels of high-sensitivity CRP (hsCRP), endothelin-1 (ET1), insulin, and testosterone determinations.

RESULTS

In PCOS women hsCRP (2.35+/-2.14 mg/L vs. 1.01+/-1.28 mg/L; P=0.04), ET1 (23.6+/-10.3 ng/L vs. 7.7+/-15.9 ng/L; P=0.01), and insulin (16.5+/-7.8 mIU/L vs. 11.8+/-10.7 mIU/L; P=0.03) levels were significantly higher, and QTc interval significantly shorter than in controls (401+/-61 ms vs. 467+/-61 ms; P=0.007). In 67 (56%) PCOS patients with a short QTc interval (<400 ms), plasma testosterone levels were significantly higher than in PCOS women with normal QTc interval (2.3+/-2.1 nmol/L vs. 1.4+/-1.7 nmol/L; P=0.02).

CONCLUSIONS

In patients with polycystic ovary syndrome increased testosterone levels may attenuate the effects of coronary risk factors.