Pembrolizumab-induced severe rejection and graft intolerance syndrome resulting in renal allograft nephrectomy

Early allogeneic immune modulation after establishment of donor hematopoietic cell-induced mixed chimerism in a nonhuman primate kidney transplant model

Background

Mixed lymphohematopoietic chimerism is a proven strategy for achieving operational transplant tolerance, though the underlying immunologic mechanisms are incompletely understood.

Methods

A post-transplant, non-myeloablative, tomotherapy-based total lymphoid (TLI) irradiation protocol combined with anti-thymocyte globulin and T cell co-stimulatory blockade (belatacept) induction was applied to a 3-5 MHC antigen mismatched rhesus macaque kidney and hematopoietic cell transplant model. Mechanistic investigations of early (60 days post-transplant) allogeneic immune modulation induced by mixed chimerism were conducted.

Results

Chimeric animals demonstrated expansion of circulating and graft-infiltrating CD4+CD25+Foxp3+ regulatory T cells (Tregs), as well as increased differentiation of allo-protective CD8+ T cell phenotypes compared to naïve and non-chimeric animals. In vitro mixed lymphocyte reaction (MLR) responses and donor-specific antibody production were suppressed in animals with mixed chimerism. PD-1 upregulation was observed among CD8+ T effector memory (CD28-CD95+) subsets in chimeric hosts only. PD-1 blockade in donor-specific functional assays augmented MLR and cytotoxic responses and was associated with increased intracellular granzyme B and extracellular IFN-γ production.

Conclusions

These studies demonstrated that donor immune cell engraftment was associated with early immunomodulation via mechanisms of homeostatic expansion of Tregs and early PD-1 upregulation among CD8+ T effector memory cells. These responses may contribute to TLI-based mixed chimerism-induced allogenic tolerance.

Multi-gene mutation metastatic castrate-resistant prostate cancer

Gene panel sequencing of metastatic castrate-resistant prostate cancer (mCRPC) can assist in identifying appropriate targeted therapies. Although some studies have reported single DNA mutations, this is the first case of mCRPC with five different DNA mutations based on gene panel analysis. The patient, a 75-year-old man, initially presented with haematuria. Laboratory investigation revealed elevated prostate-specific antigen levels, and CT showed an enlarged prostate gland with metastatic lymph nodes. A 12-core biopsy revealed adenocarcinoma of the prostate. Gene panel sequencing demonstrated five different DNA mutations associated with sensitivities to olaparib and pembrolizumab. Treatment failure after hormonal therapy with leuprorelin and bicalutamide resulted in the initiation of chemotherapy with docetaxel. Over the past decade, development of genome sequencing analysis may guide us with more precise targeted therapy specific to mCRPC early on, especially with poly (ADP-ribose) polymerase inhibitors may show survival benefits.

Application of Immune Checkpoint Inhibitors in Solid Organ Transplantation Recipients: A Systematic Review

BACKGROUND

Solid organ transplantation (SOT) is a treatment method for end-stage organ diseases and improve their life quality, while using long-term immunosuppressant drugs (ISD) is needed to suppress the function of the immune system. Immune checkpoint inhibitors (ICIs) are a class of anti-tumor drugs that kill tumors by activating the autoimmune system. The primary objective of our systematic review is to investigate the risk factors for organ rejection and the efficacy of ICIs in solid organ transplantation recipients (SOTRs).

METHODS

We searched four databases to find relevant articles up to January 2021. A total of 61 articles involving 106 SOTRs met the screening criteria and were included in our systematic review. The collected data were statistical described, and the risk factors were analyzed by logistic regression.

RESULTS

Forty-four patients (41.5%) developed host-versus-graft response (HVGR) after ICIs. mTOR inhibitors (pre-ICIs) (p = 0.069, OR = 0.377, 95% CI 0.132-1.078) and calcineurin inhibitors (post-ICIs) (p = 0.056, OR = 0.375, 95%CI 0.137-1.025) may help reduce the incidence of HVGR. Hormones (pre-ICIs) (p = 0.026, OR = 3.150, 95%CI 1.150-8.628) and anti-metabolites (pre-ICIs) (p = 0.022, OR = 3.214, 95%CI 1.185-8.720) may adversely affect the efficacy of ICIs. Only 35.6% of patients both responded well to ICIs treatment and did not develop HVGR.

CONCLUSIONS

Our systematic review summarizes the use of ICIs in SOTRs and evaluates the efficacy of ICIs and the risk factors that induce HVGR. Through risk factor analysis, we found that mTOR inhibitors and calcineurin inhibitors may help to reduce the occurrence of HVGR; hormones and anti-metabolic drugs may have adverse effects on the efficacy of ICIs. In addition, there is a contradictory relationship between the occurrence of HVGR and the efficacy of ICIs.

Epidemiology, Staging and Management of Prostate Cancer

Prostate cancer is the second most common and fifth most aggressive neoplasm among men worldwide. It is particularly incident in high human development index (HDI) nations, with an estimated one in seven men in the US receiving a prostate cancer diagnosis in their lifetime. A rapid rise and then fall in prostate cancer incidence in the US and Europe corresponded to the implementation of widespread prostate specific antigen (PSA) testing in 1986 and then subsequent fall from favor due to high rates of false positives, overdiagnosis, and overtreatment (as many as 20-50% of men diagnosed could have remained asymptomatic in their lifetimes). Though few risk factors have been characterized, the best known include race (men of African descent are at higher risk), genetics (e.g., BRCA1/2 mutations), and obesity. The Gleason scoring system is used for histopathological staging and is combined with clinical staging for prognosis and treatment. National guidelines have grown more conservative over the past decades in management, recommending watchful waiting and observation in older men with low to intermediate risk disease. Among higher risk patients, prostatectomy (robotic is preferred) and/or external beam radiotherapy is the most common interventions, followed by ADT maintenance. Following progression on androgen deprivation therapy (ADT) (known as castration-resistance), next generation endocrine therapies like enzalutamide, often in combination with cytotoxic agent docetaxel, are standard of care. Other promising treatments include Radium-223 for bone metastases, pembrolizumab for programmed death ligand-1 (PDL1) and microsatellite instability (MSI) high disease, and poly ADP ribose polymerase (PARP) inhibitors for those with mutations in homologous recombination (most commonly BRCA2).