Anti-HLA serologic response to CD38-targeting desensitization therapy is challenged by peripheral memory B cells in highly sensitized kidney transplant candidates.

High human leukocyte antigen (HLA) sensitization limits access to compatible transplantation. New CD38-targeting agents have been shown to reduce anti-HLA antibodies, although with important interpatient variability. Thus, pretreatment identification of responder and nonresponder (NR) patients is needed for treatment decision-making. We analyzed 26 highly sensitized (HS) patients from 2 desensitization trials using anti-CD38 monoclonal antibodies. Hierarchical clustering identified 3 serologic responder groups: high responders, low responders, and NR. Spectral flow cytometry and functional HLA-specific memory B cell (mBC) assessment were first conducted on peripheral blood mononuclear cells and bone marrow samples from 16 patients treated with isatuximab (NCT04294459). Isatuximab effectively depleted bone marrow plasma cells, peripheral CD38-expressing plasmablasts, plasma cells, transitional B cells, and class-switch mBCs, ultimately reducing frequencies of HLA-specific immunoglobulin G (IgG)-producing mBCs. Multidimensional spectral flow cytometry with partial least squares discriminant analysis revealed that pretreatment abundance of specific circulating mBC phenotypes, especially CD38neg class-switch mBCs, accurately distinguished between high serologic responders and low responders or NR (AUC 0.958, 0.860-1.000, P = .009), who also displayed significantly lower frequencies of HLA-specific IgG-producing mBCs (P < .0001). This phenotypical mBC signature predicting response to therapy was validated in an external HS patient cohort (n = 10) receiving daratumumab (NCT04204980). This study identifies critical circulating mBC subset phenotypes that distinguish HS patients with successful serologic responses to CD38-targeting desensitization therapies, potentially guiding treatment decision-making.

Impact of diet-induced maternal obesity on the reproductive capacity of F1 female offspring and the early development of the second generation.

The aim of this study was to examine the impact of maternal obesity on the reproductive capacity of the female offspring (F1) and on the early development of the second generation (F2). To this end, rats were fed either standard (SD) or cafeteria (CD) diet. CD rats and their offspring were divided into 2 groups: rats with 18% and ≥25% overweight (CD18 and CD25, respectively) and offspring from CD18 and CD25 rats (OCD18 and OCD25, respectively). Both OCD groups achieved greater weight gain than controls, without changes in the serum levels of glucose, cholesterol or triglycerides. However, they showed increased gonadal cholesterol concentration and fat content compared to controls. Female OCD groups showed a slight prolongation of the estrous cycle and different pattern of changes in the weight gain during pregnancy. The OCD25 group displayed an increased fertility index and preimplantation losses, and changes in some fetal measurements. Some OCD25 dams gave birth to a larger litter of pups and displayed a lower viability index and lactation rate than controls. OCD25 dams also showed an increase in estradiol and a decrease in testosterone and anti-Müllerian hormone. OCD25 rats showed increased mRNA levels of steroidogenenic enzymes. The offspring from OCD25 females (F2OCD25 offspring) showed early vaginal opening and higher ovulation rate in females, and lower ano-genital distances in males, compared to controls. In conclusion, these results reflect that maternal obesity impacts on the reproductive health of successive generations, probably as a result of epigenetic changes in different systems, including germ cells.

Corrigendum: Impaired antigen-specific B-cell responses after Influenza vaccination in kidney transplant recipients receiving co-stimulation blockade with Belatacept.

[This corrects the article DOI: 10.3389/fimmu.2022.918887.].

High-dimensional mass cytometry identified circulating natural killer T-cell subsets associated with protection from cytomegalovirus infection in kidney transplant recipients.

Cytomegalovirus (CMV) infection is associated with poor kidney transplant outcomes. While innate and adaptive immune cells have been implicated in its prevention, an in-depth characterization of the in vivo kinetics of multiple cell subsets and their role in protecting against CMV infection has not been achieved. Here, we performed high-dimensional immune phenotyping by mass cytometry, and functional assays, on 112 serially collected samples from CMV seropositive kidney transplant recipients. Advanced unsupervised deep learning analysis was used to assess immune cell populations that significantly correlated with prevention against CMV infection and anti-viral immune function. Prior to infection, kidney transplant recipients who developed CMV infection showed significantly lower CMV-specific cell-mediated immune (CMI) frequencies than those that did not. A broad diversity of circulating cell subsets within innate and adaptive immune compartments were associated with CMV infection or protective CMV-specific CMI. While percentages of CMV (tetramer-stained)-specific T cells associated with high CMI responses and clinical protection, circulating CD3+CD8midCD56+ NK-T cells overall strongly associated with low CMI and subsequent infection. However, three NK-T cell subsets sharing the CD11b surface marker associated with CMV protection and correlated with strong anti-viral CMI frequencies in vitro. These data were validated in two external independent cohorts of kidney transplant recipients. Thus, we newly describe the kinetics of a novel NK-T cell subset that may have a protective role in post-transplantation CMV infection. Our findings pave the way to more mechanistic studies aimed at understanding the function of these cells in protection against CMV infection.

Qualitative, rather than quantitative, differences between HLA-DQ alleles affect HLA-DQ immunogenicity in organ transplantation.

Prolonging the lifespan of transplanted organs is critical to combat the shortage of this life-saving resource. Chronic rejection, with irreversible demise of the allograft, is often caused by the development of donor-specific HLA antibodies. Currently, enumerating molecular (amino acid) mismatches between recipient and donor is promoted to identify patients at higher risk of developing HLA antibodies, for use in organ allocation, and immunosuppression-minimization strategies. We have counseled against the incorporation of such approaches into clinical use and hypothesized that not all molecular mismatches equally contribute to generation of donor-specific immune responses. Herein, we document statistical shortcomings in previous study design: for example, use of individuals who lack the ability to generate donor-specific-antibodies (HLA identical) as part of the negative cohort. We provide experimental evidence, using CRISPR-Cas9-edited cells, to rebut the claim that the HLAMatchmaker eplets represent "functional epitopes." We further used unique sub-cohorts of patients, those receiving an allograft with two HLA-DQ mismatches yet developing antibodies only to one mismatch (2MM1DSA), to interrogate differential immunogenicity. Our results demonstrate that mismatches of DQα05-heterodimers exhibit the highest immunogenicity. Additionally, we demonstrate that the DQα chain critically contributes to the overall qualities of DQ molecules. Lastly, our data proposes that an augmented risk to develop donor-specific HLA-DQ antibodies is dependent on qualitative (evolutionary and functional) divergence between recipient and donor, rather than the mere number of molecular mismatches. Overall, we propose an immunological mechanistic rationale to explain differential HLA-DQ immunogenicity, with potential ramifications for other pathological processes such as autoimmunity and infections.

Expression of Rejection-Associated Transcripts in Early Protocol Renal Transplant Biopsies Is Associated with Tacrolimus Exposure and Graft Outcome.

Subclinical inflammation in protocol biopsies relates to tacrolimus exposure and human leukocyte antigen (HLA) matching. We aimed to characterize transcripts associated with rejection and tacrolimus exposure and the latter's association with transplant outcomes. We tested whether gene expression is associated with rejection using strictly normal protocol biopsies (n = 17) and biopsies with T cell-mediated rejection (TCMR) or antibody-mediated rejection (ABMR) according to Banff criteria (n = 12). Subsequently, we analyzed these transcripts in a set of 4-month protocol biopsies (n = 137) to assess their association with donor and recipient characteristics, the intensity of immunosuppression, and the graft outcome. Differential expression (false discovery rate (FDR) < 0.01, fold (change (FC) > 3) between normal and rejection biopsies yielded a set of 111 genes. In the protocol biopsy cohort (n = 137), 19 out of these 111 genes correlated with tacrolimus trough levels at the time of biopsy (TAC-C0), and unsupervised analysis split this cohort into two clusters. The two clusters differed in donor age and tacrolimus trough levels. Subclinical rejection, including borderline lesions, tended to occur in the same cluster. Logistic regression analysis indicated that TAC-C0 at the time of biopsy (OR: 0.83, 95%CI:0.72-0.06, p = 0.0117) was associated with cluster 2. In a follow-up averaging 70 ± 30 months, this patient group displayed a significant decline in renal function (p = 0.0135). The expression of rejection-associated transcripts in early protocol biopsies is associated with tacrolimus exposure and a faster decline in renal function.

HLA (emphasis on DQ) compatibility for longer allograft survival in pediatric transplantation: Modern evidence and challenges.

Kidney transplantation is the treatment of choice for children with end-stage kidney failure, yet suboptimal outcomes, the need for long-term immunosuppression, and the dependency on consecutive transplants pose significant barriers to success. Providing better HLA-matched organs to pediatric patients seems to be the most logical approach to improve graft and patient outcomes and to reduce risk of anti-HLA sensitization after graft failure. We here review recent literature on HLA matching in pediatric kidney transplantation. We further review newer approaches attempting to improve matching by using molecular mismatch load analysis. Our main focus is on the role of HLA-DQ compatibility between recipient and donor. We further emphasize the need to develop creative approaches that will support HLA (and DQ) matching utilization in organ allocation schemes, at least in those geared specifically for pediatric patients.

Tacrolimus After rATG and Infliximab Induction Immunosuppression-RIMINI Trial.

BACKGROUND: Infliximab selectively targets recently activated effector cells and, as an induction agent, might enable the safe elimination of mycophenolate from maintenance immunosuppression in kidney transplantation. METHODS: This is a phase II international multicenter open-label single-arm confidence interval (CI)-based clinical trial of the BIO-DrIM EU consortium aimed at assessing the efficacy and safety of rabbit antithymocyte globulin and infliximab induction in kidney transplantation. Sixty-seven primary kidney transplant recipients at low risk (panel-reactive antibodies <20%, no donor-specific antibodies [DSA]) received rabbit antithymocyte globulin (2 × 1.5 mg/kg, postoperative days 0 and 1) and infliximab (5 mg/kg, postoperative day 2), followed by mycophenolate-free tacrolimus-based immunosuppression for 12 mo. The primary endpoint was efficacy failure, defined as a composite of acute rejection, graft loss, or poor graft function (estimated glomerular filtration rate <40 mL/min) at 12 mo and was based on the endpoint of the comparator study. Additionally, a historical propensity-matched control cohort was established. RESULTS: Primary endpoint occurred in 22 of 67 patients (32.84%), with upper bound of an exact 1-sided 95% CI of 43.47%, which met the predefined criteria (efficacy failure of <40% and upper-bound 95% CI of <50%) and was similar in the historical matched cohort. By 12 mo, 79.1% of patients remained on the study protocol. Lower rates of BK replication (6% versus 22.4%; P = 0.013) but higher rates of de novo DSAs (11.9% versus 1.5%; P = 0.039) were observed in the study cohort. CONCLUSIONS: A similar efficacy of the study immunosuppression regimen to the comparator study and the historical matched cohort was found. However, a higher de novo DSA emergence points to an increased risk of antibody-mediated rejection (NCT04114188).

A prospective controlled, randomized clinical trial of kidney transplant recipients developed personalized tacrolimus dosing using model-based Bayesian Prediction.

For three decades, tacrolimus (Tac) dose adjustment in clinical practice has been calculated empirically according to the manufacturer's labeling based on a patient's body weight. Here, we developed and validated a Population pharmacokinetic (PPK) model including pharmacogenetics (cluster CYP3A4/CYP3A5), age, and hematocrit. Our study aimed to assess the clinical applicability of this PPK model in the achievement of Tac Co (therapeutic trough Tac concentration) compared to the manufacturer's labelling dosage. A prospective two-arm, randomized, clinical trial was conducted to determine Tac starting and subsequent dose adjustments in 90 kidney transplant recipients. Patients were randomized to a control group with Tac adjustment according to the manufacturer's labeling or the PPK group adjusted to reach target Co (6-10 ng/ml) after the first steady state (primary endpoint) using a Bayesian prediction model (NONMEM). A significantly higher percentage of patients from the PPK group (54.8%) compared with the control group (20.8%) achieved the therapeutic target fulfilling 30% of the established superiority margin defined. Patients receiving PPK showed significantly less intra-patient variability compared to the control group, reached the Tac Co target sooner (5 days vs 10 days), and required significantly fewer Tac dose modifications compared to the control group within 90 days following kidney transplant. No statistically significant differences occurred in clinical outcomes. Thus, PPK-based Tac dosing offers significant superiority for starting Tac prescription over classical labeling-based dosing according to the body weight, which may optimize Tac-based therapy in the first days following transplantation.

HLA-DQ antibodies in alloimmunity, what makes them different?

PURPOSE OF REVIEW: De novo HLA-DQ antibodies are the most frequently observed after solid-organ allotransplantation; and are associated with the worse adverse graft outcomes compared with all other HLA antibodies. However, the biological explanation for this observation is not yet known. Herein, we examine unique characteristics of alloimmunity directed specifically against HLA-DQ molecules. RECENT FINDINGS: While investigators attempted to decipher functional properties of HLA class II antigens that may explain their immunogenicity and pathogenicity, most early studies focused on the more expressed molecule - HLA-DR. We here summarize up-to-date literature documenting specific features of HLA-DQ, as compared to other class II HLA antigens. Structural and cell-surface expression differences have been noted on various cell types. Some evidence suggests variations in antigen-presenting function and intracellular activation pathways after antigen/antibody interaction. SUMMARY: The clinical effects of donor-recipient incompatibility at HLA-DQ, the risk of generating de novo antibodies leading to rejection, and the inferior graft outcomes indicate increased immunogenicity and pathogenicity that is unique to this HLA antigen. Clearly, knowledge generated for HLA-DR cannot be applied interchangeably. Deeper understanding of features unique to HLA-DQ may support the generation of targeted preventive-therapeutic strategies and ultimately improve solid-organ transplant outcomes.

On the clinical relevance of using complete high-resolution HLA typing for an accurate interpretation of posttransplant immune-mediated graft outcomes.

Complete and high-resolution (HR) HLA typing improves the accurate assessment of donor-recipient compatibility and pre-transplant donor-specific antibodies (DSA). However, the value of this information to identify de novo immune-mediated graft events and its impact on outcomes has not been assessed. In 241 donor/recipient kidney transplant pairs, DNA samples were re-evaluated for six-locus (A/B/C/DRB1/DQB1+A1/DPB1) HR HLA typing. De novo anti-HLA antibodies were assessed using solid-phase assays, and dnDSA were classified either (1) as per current clinical practice according to three-locus (A/B/DRB1) low-resolution (LR) typing, estimating donor HLA-C/DQ typing with frequency tables, or (2) according to complete six-locus HR typing. The impact on graft outcomes was compared between groups. According to LR HLA typing, 36 (15%) patients developed dnDSA (LR_dnDSA+). Twenty-nine out of 36 (80%) were confirmed to have dnDSA by HR typing (LR_dnDSA+/HR_dnDSA+), whereas 7 (20%) did not (LR_dnDSA+/HR_dnDSA-). Out of 49 LR_dnDSA specificities, 34 (69%) were confirmed by HR typing whereas 15 (31%) LR specificities were not confirmed. LR_dnDSA+/HR_dnDSA+ patients were at higher risk of ABMR as compared to dnDSA- and LR_dnDSA+/HR_dnDSA- (logRank < 0.001), and higher risk of death-censored graft loss (logRank = 0.001). Both LR_dnDSA+ (HR: 3.51, 95% CI = 1.25-9.85) and LR_dnDSA+/HR_dnDSA+ (HR: 4.09, 95% CI = 1.45-11.54), but not LR_dnDSA+/HR_dnDSA- independently predicted graft loss. The implementation of HR HLA typing improves the characterization of biologically relevant de novo anti-HLA DSA and discriminates patients with poorer graft outcomes.

Impaired antigen-specific B-cell responses after Influenza vaccination in kidney transplant recipients receiving co-stimulation blockade with Belatacept.

Emerging data suggest that costimulation blockade with belatacept effectively controls humoral alloimmune responses. However, whether this effect may be deleterious for protective anti-infectious immunity remains poorly understood. We performed a mechanistic exploratory study in 23 kidney transplant recipients receiving either the calcineurin-inhibitor tacrolimus (Tac, n=14) or belatacept (n=9) evaluating different cellular immune responses after influenza vaccination such as activated T follicular Helper (Tfh), plasmablasts and H1N1 hemagglutinin (HA)-specific memory B cells (HA+mBC) by flow-cytometry, and anti-influenza antibodies by hemagglutination inhibition test (HI), at baseline and days 10, 30 and 90 post-vaccination. The proportion of CD4+CD54RA-CXCR5+ Tfh was lower in belatacept than Tac patients at baseline (1.86%[1.25-3.03] vs 4.88%[2.40-8.27], p=0.01) and remained stable post-vaccination. At M3, HA+mBc were significantly higher in Tac-treated patients (0.56%[0.32-1.49] vs 0.27%[0.13-0.44], p=0.04) and correlated with activated Tfh numbers. When stratifying patients according to baseline HA+mBc frequencies, belatacept patients with low HA+mBC displayed significantly lower HA+mBc increases after vaccination than Tac patients (1.28[0.94-2.4] vs 2.54[1.73-5.70], p=0.04). Also, belatacept patients displayed significantly lower seroprotection rates against H1N1 at baseline than Tac-treated patients (44.4% vs 84.6%) as well as lower seroconversion rates at days 10, 30 and 90 after vaccination (50% vs 0%, 63.6% vs 0%, and 63.6% vs 0%, respectively). We show the efficacy of belatacept inhibiting T-dependent antigen-specific humoral immune responses, active immunization should be highly encouraged before starting belatacept therapy.

Tacrolimus CYP3A Single-Nucleotide Polymorphisms and Preformed T- and B-Cell Alloimmune Memory Improve Current Pretransplant Rejection-Risk Stratification in Kidney Transplantation.

Achieving fast immunosuppression blood exposure after kidney transplantation is key to abrogating both preformed and de novo anti-donor humoral and cellular alloresponses. However, while tacrolimus (TAC) is the cornerstone immunosuppressant inhibiting adaptive alloimmunity, its blood exposure is directly impacted by different single-nucleotide polymorphisms (SNPs) in CYP3A TAC-metabolizing enzymes. Here, we investigated how functional TAC-CYP3A genetic variants (CYP3A4*22/CYP3A5*3) influence the main baseline clinical and immunological risk factors of biopsy-proven acute rejection (BPAR) by means of preformed donor-specific antibodies (DSAs) and donor-specific alloreactive T cells (DSTs) in a large European cohort of 447 kidney transplants receiving TAC-based immunosuppression. A total of 70 (15.7%) patients developed BPAR. Preformed DSAs and DSTs were observed in 12 (2.7%) and 227 (50.8%) patients, respectively. According to the different CYP3A4*22 and CYP3A5*3 functional allele variants, we found 4 differential new clusters impacting fasting TAC exposure after transplantation; 7 (1.6%) were classified as high metabolizers 1 (HM1), 71 (15.9%) as HM2, 324 (72.5%) as intermediate (IM), and 45 (10.1%) as poor metabolizers (PM1). HM1/2 showed significantly lower TAC trough levels and higher dose requirements than IM and PM (p < 0.001) and more frequently showed TAC underexposure (<5 ng/ml). Multivariate Cox regression analyses revealed that CYP3A HM1 and IM pharmacogenetic phenotypes (hazard ratio (HR) 12.566, 95% CI 1.99-79.36, p = 0.007, and HR 4.532, 95% CI 1.10-18.60, p = 0.036, respectively), preformed DSTs (HR 3.482, 95% CI 1.99-6.08, p < 0.001), DSAs (HR 4.421, 95% CI 1.63-11.98, p = 0.003), and delayed graft function (DGF) (HR 2.023, 95% CI 1.22-3.36, p = 0.006) independently predicted BPAR. Notably, a significant interaction between T-cell depletion and TAC underexposure was observed, showing a reduction of the BPAR risk (HR 0.264, 95% CI 0.08-0.92, p = 0.037). Such variables except for DSAs displayed a higher predictive risk for the development of T cell-mediated rejection (TCMR). Refinement of pretransplant monitoring by incorporating TAC CYP3A SNPs with preformed DSAs as well as DSTs may improve current rejection-risk stratification and help induction treatment decision-making.

Long-lasting adaptive immune memory specific to SARS-CoV-2 in convalescent coronavirus disease 2019 stable people with HIV.

OBJECTIVE: While the course of natural immunization specific to SARS-CoV-2 has been described among convalescent coronavirus disease 2019 (COVID-19) people without HIV (PWOH), a thorough evaluation of long-term serological and functional T- and B-cell immune memory among people with HIV (PWH) has not been reported. METHODS: Eleven stable PWH developing mild ( n  = 5) and severe ( n  = 6) COVID-19 and 39 matched PWOH individuals with mild (MILD) ( n  = 20) and severe (SEV) ( n  = 19) COVID-19 infection were assessed and compared at 3 and 6 months after infection for SARS-CoV-2-specific serology, polyfunctional cytokine (interferon-γ [IFN-γ], interleukin 2 [IL-2], IFN-γ/IL-2, IL-21) producing T-cell frequencies against four main immunogenic antigens and for circulating SARS-CoV-2-specific immunoglobulin G (IgG)-producing memory B-cell (mBc). RESULTS: In all time points, all SARS-COV-2-specific adaptive immune responses were highly driven by the clinical severity of COVID-19 infection, irrespective of HIV disease. Notably, while a higher proportion of mild PWH showed a higher decay on serological detection between the two time points as compared to PWOH, persistently detectable IgG-producing mBc were still detectable in most patients (4/4 (100%) for SEV PWH, 4/5 (80%) for MILD PWH, 10/13 (76.92%) for SEV PWOH and 15/18 (83.33%) for MILD PWOH). Likewise, SARS-CoV-2-specific IFN-γ-producing T-cell frequencies were detected in both PWH and PWOH, although significantly more pronounced among severe COVID-19 (6/6 (100%) for SEV PWH, 3/5 (60%) for MILD PWH, 18/19 (94.74%) for SEV PWOH and 14/19 (73.68%) for MILD PWOH). CONCLUSIONS: PWH develop a comparable short and long-term natural functional cellular and humoral immune response than PWOH convalescent patients, which are highly influenced by the clinical severity of the COVID-19 infection.

A comprehensive assessment of long-term SARS-CoV-2-specific adaptive immune memory in convalescent COVID-19 Solid Organ Transplant recipients.

Long-term adaptive immune memory has been reported among immunocompetent individuals up to eight months following SARS-CoV-2 infection. However, limited data is available in convalescent patients with a solid organ transplant. To investigate this, we performed a thorough evaluation of adaptive immune memory at different compartments (serological, memory B cells and cytokine [IFN-γ, IL-2, IFN-γ/IL12 and IL-21] producing T cells) specific to SARS-CoV-2 by ELISA and FluoroSpot-based assays in 102 convalescent patients (53 with a solid organ transplants (38 kidney, 5 liver, 5 lung and 5 heart transplant) and 49 immunocompetent controls) with different clinical COVID-19 severity (severe, mild and asymptomatic) beyond six months after infection. While similar detectable memory responses at different immune compartments were detected between those with a solid organ transplant and immunocompetent individuals, these responses were predominantly driven by distinct COVID-19 clinical severities (97.6%, 80.5% and 42.1%, all significantly different, were seropositive; 84% vs 75% vs 35.7%, all significantly different, showed IgG-producing memory B cells and 82.5%, 86.9% and 31.6%, displayed IFN-γ producing T cells; in severe, mild and asymptomatic convalescent patients, respectively). Notably, patients with a solid organ transplant with longer time after transplantation did more likely show detectable long-lasting immune memory, regardless of COVID-19 severity. Thus, our study shows that patients with a solid organ transplant are capable of maintaining long-lasting peripheral immune memory after COVID-19 infection; mainly determined by the degree of infection severity.

Diet-induced maternal obesity and overnutrition cause a decrease in the sperm quality of the offspring.

The present work aimed to study the changes caused by maternal obesity and overnutrition in both the quality and function of spermatozoa of the offspring. To this end, female rats received either a standard or cafeteria diet from 22 days of age until the weaning of their offspring, and the male offspring from rats fed the standard and cafeteria diet (OSD and OCD respectively) were used. Different endpoints in the offspring, as body weight, weight gain, and glycemia were recorded and the testes were removed at 60 days of age. Different spermatozoa parameters, such as mitochondrial function, functional integrity of the sperm plasma membrane, capacitation, and acrosome status, were evaluated. The OCD group was heavier than the OSD group and exhibited lower testis and epididymal indices. The OCD group also showed a decrease in the ability of the sperm tail to react in the presence of a hypoosmotic solution, deficiency in sperm mitochondrial function, a lower percentage of spermatozoa without acrosome when exposed to a capacitation medium, and a higher number of abnormal metaphases. In addition, compared with OSD, OCD rats had a higher number of TUNEL-positive cells in the histological sections of the testis, and greater presence of reactive oxygen species in the spermatozoa, evaluated by a fluorescent probe. However, the OCD group displayed lower protein levels of cytochrome c and caspase-3 in testis tissue than the control group. These results suggest that maternal obesity and overnutrition program the offspring to develop poor sperm quality and function, which may imply a condition of subfertility.

Immunosuppressive drugs modes of action.

The innate and adaptive immune systems work as a complex interplay between different cell types, involving cytokines and chemokines mediating extracellular and paracrine effects. At the intracellular level, the inflammatory cascade is mediated by multifaceted processes that have been better described in the last 10 years. Immunosuppressive agents available in clinical practice act at different points of those cascades at the intracellular or extracellular level. Those drugs can mediate their effects on one or more cell types finally limiting inflammation and immune responses to antigens. Every immunosuppressive agent is characterized by intrinsic toxicity and side effects that may be due to the same therapeutic pathways or to off-target secondary effect of each molecule. We will here review the mechanisms of action of the most widely used immunosuppressive agents in the field of solid organ transplantation and autoimmune disorders, describing the mechanisms underlying both the therapeutic and secondary effects.

Acute Kidney Injury Following Chimeric Antigen Receptor T-Cell Therapy for B-Cell Lymphoma in a Kidney Transplant Recipient.

Anti-CD19 chimeric antigen receptor (CAR) T-cell therapy is a newer and effective therapeutic option approved for patients with relapsed/refractory acute lymphoblastic leukemia and diffuse large B-cell lymphoma. Acute kidney injury is a complication of CAR T-cell therapy that can result in kidney failure. In most cases, it is thought to be related to hemodynamic changes due to cytokine release syndrome. Kidney biopsy in this clinical scenario is usually not performed. We report on a kidney transplant recipient in his 40s who developed a posttransplant lymphoproliferative disorder of B-cell origin refractory to conventional treatments and received anti-CD19 CAR T-cell therapy as compassionate treatment. Beginning on day 12 after CAR T-cell infusion, in the absence of clinical symptoms, a progressive decline in estimated glomerular filtration rate of the kidney graft occurred. A subsequent allograft biopsy showed mild tubulointerstitial lymphocyte infiltrates, falling into a Banff borderline-changes category and resembling an acute immunoallergic tubulointerstitial nephritis. Neither CAR T cells nor lymphomatous B cells were detected within the graft cellular infiltrates, suggesting an indirect mechanism of kidney injury. Although kidney graft function partially recovered after steroid therapy, the posttransplant lymphoproliferative disorder progressed and the patient died 7 months later.

Influence of the Circadian Timing System on Tacrolimus Pharmacokinetics and Pharmacodynamics After Kidney Transplantation.

Introduction: Tacrolimus is the backbone immunosuppressant after solid organ transplantation. Tacrolimus has a narrow therapeutic window with large intra- and inter-patient pharmacokinetic variability leading to frequent over- and under-immunosuppression. While routine therapeutic drug monitoring (TDM) remains the standard of care, tacrolimus pharmacokinetic variability may be influenced by circadian rhythms. Our aim was to analyze tacrolimus pharmacokinetic/pharmacodynamic profiles on circadian rhythms comparing morning and night doses of a twice-daily tacrolimus formulation. Methods: This is a post-hoc analysis from a clinical trial to study the area under curve (AUC) and the area under effect (AUE) profiles of calcineurin inhibition after tacrolimus administration in twenty-five renal transplant patients. Over a period of 24 h, an intensive sampling (0, 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12, 12.5, 13, 13.5, 14, 15, 20, and 24 h) was carried out. Whole blood and intracellular tacrolimus concentrations and calcineurin activity were measured by UHPLC-MS/MS. Results: Whole blood and intracellular AUC12-24 h and Cmax achieved after tacrolimus night dose was significantly lower than after morning dose administration (AUC0-12 h) (p < 0.001 for both compartments). AUE0-12 h and AUE12-24 h were not statistically different after morning and night doses. Total tacrolimus daily exposure (AUC0-24 h), in whole blood and intracellular compartments, was over-estimated when assessed by doubling the morning AUC0-12 h data. Conclusion: The lower whole blood and intracellular tacrolimus concentrations after night dose might be influenced by a distinct circadian clock. This significantly lower tacrolimus exposure after night dose was not translated into a significant reduction of the pharmacodynamic effect. Our study may provide conceptual bases for better understanding the TDM of twice-daily tacrolimus formulation.

Preformed T cell alloimmunity and HLA eplet mismatch to guide immunosuppression minimization with tacrolimus monotherapy in kidney transplantation: Results of the CELLIMIN trial.

Personalizing immunosuppression is a major objective in transplantation. Transplant recipients are heterogeneous regarding their immunological memory and primary alloimmune susceptibility. This biomarker-guided trial investigated whether in low immunological-risk kidney transplants without pretransplant DSA and donor-specific T cells assessed by a standardized IFN-γ ELISPOT, low immunosuppression (LI) with tacrolimus monotherapy would be non-inferior regarding 6-month BPAR than tacrolimus-based standard of care (SOC). Due to low recruitment rates, the trial was terminated when 167 patients were enrolled. ELISPOT negatives (E-) were randomized to LI (n = 48) or SOC (n = 53), E+ received the same SOC. Six- and 12-month BPAR rates were higher among LI than SOC/E- (4/35 [13%] vs. 1/43 [2%], p = .15 and 12/48 [25%] vs. 6/53 [11.3%], p = .073, respectively). E+ patients showed similarly high BPAR rates than LI at 6 and 12 months (12/55 [22%] and 13/66 [20%], respectively). These differences were stronger in per-protocol analyses. Post-hoc analysis revealed that poor class-II eplet matching, especially DQ, discriminated E- patients, notably E-/LI, developing BPAR (4/28 [14%] low risk vs. 8/20 [40%] high risk, p = .043). Eplet mismatch also predicted anti-class-I (p = .05) and anti-DQ (p < .001) de novo DSA. Adverse events were similar, but E-/LI developed fewer viral infections, particularly polyoma-virus-associated nephropathy (p = .021). Preformed T cell alloreactivity and HLA eplet mismatch assessment may refine current baseline immune-risk stratification and guide immunosuppression decision-making in kidney transplantation.