Daratumumab in Sensitized Kidney Transplantation: Potentials and Limitations of Experimental and Clinical Use.

BACKGROUND: Donor-specific antibodies are associated with increased risk of antibody-mediated rejection and decreased allograft survival. Therefore, reducing the risk of these antibodies remains a clinical need in transplantation. Plasma cells are a logical target of therapy given their critical role in antibody production. METHODS: To target plasma cells, we treated sensitized rhesus macaques with daratumumab (anti-CD38 mAb). Before transplant, we sensitized eight macaques with two sequential skin grafts from MHC-mismatched donors; four of them were also desensitized with daratumumab and plerixafor (anti-CXCR4). We also treated two patients with daratumumab in the context of transplant. RESULTS: The animals treated with daratumumab had significantly reduced donor-specific antibody levels compared with untreated controls (57.9% versus 13% reduction; P<0.05) and prolonged renal graft survival (28.0 days versus 5.2 days; P<0.01). However, the reduction in donor-specific antibodies was not maintained because all recipients demonstrated rapid rebound of antibodies, with profound T cell-mediated rejection. In the two clinical patients, a combined heart and kidney transplant recipient with refractory antibody-mediated rejection and a highly sensitized heart transplant candidate, we also observed a significant decrease in class 1 and 2 donor-specific antibodies that led to clinical improvement of antibody-mediated rejection and to heart graft access. CONCLUSIONS: Targeting CD38 with daratumumab significantly reduced anti-HLA antibodies and anti-HLA donor-specific antibodies in a nonhuman primate model and in two transplant clinical cases before and after transplant. This supports investigation of daratumumab as a potential therapeutic strategy; however, further research is needed regarding its use for both antibody-mediated rejection and desensitization.

Accelerated ISAV replication detection by cell culture methods combined with time-monitoring RT-qPCR.

Infectious salmon anaemia (ISA) is a viral disease that affects farmed Atlantic salmon (Salmo salar L.), often leading to mass mortalities. A quick detection of the ISA virus (ISAV) is crucial for decision-making and can prevent the occurrence of future outbreaks. Screening done by Canada's National Aquatic Animal Health Laboratory System (NAAHLS) uses quantitative reverse transcription PCR (RT-qPCR) followed by sequencing of PCR amplicons. As neither technique provides information regarding the infectivity of the virus, suspected virulent strains are subsequently tested using viral isolation. However, this stepwise process can require significant time to deliver results. To speed up this delivery, we have improved on these pre-existing techniques by combining the use of cell culture with RT-qPCR to detect replicative virus in as little as 5 days. Preliminary assays enabled the establishment of a minimal shift in Ct values over time, which is representative of viral replication in cultured cells. Subsequent blind panel analyses allowed the establishment of the optimal sampling days, as well as diagnostic sensitivity (DSe) and specificity (DSp) estimates. This method could be adopted not only by laboratories conducting diagnostic analyses for ISAV, but also for other slow-replicating viral agents that replicate through a budding mechanism.

Role of C1q-binding anti-HLA antibodies as a predictor of lung allograft outcome.

Presence of anti-human leukocyte antigen donor-specific antibodies (DSAs) is associated with poor outcome after lung transplantation. Currently, DSAs are detected using the Luminex technique, which may be overly sensitive. The new C1q assay allows for the exclusive detection of complement (C1q)-binding antibodies, involved in antibody-mediated rejection. We investigated whether early detection of complement-binding DSAs is associated with chronic lung allograft dysfunction (CLAD) and survival.From 2009 to 2012, lung transplant recipients from three transplantation centres were screened for the presence of DSA and their complement-binding capacity during the 6-12 months post-transplantation in a stable condition.The analysis included 168 patients. The 3-year rates of freedom from CLAD and graft survival were lower for patients with complement-binding DSAs (33.6% and 53.7%, respectively), as compared with patients with non-complement-binding DSAs (61.9% and 77.4%, respectively) and patients without DSA (70% and 84.9%, respectively) (p<0.001 and p=0.001, respectively). Detection of complement-binding DSA was associated with a risk of graft loss that was nearly tripled after adjustment for clinical, functional, histological and immunological factors (hazard ratio 2.98, 95% CI 1.33-6.66; p=0.008).Assessment of the C1q-binding capacity of DSA appears to be useful in identifying stable lung transplant recipients at high risk of lung allograft loss.

Antibody-mediated rejection induced cardiogenic shock: Too late for conventional therapy.

BACKGROUND: Data are scarce on the prognosis of heart allograft antibody-mediated rejection (AMR) with cardiogenic shock (CS). METHODS: We performed a retrospective, single center, observational study. We included patients with biopsy-proven AMR and CS. We aimed to analyze the characteristics, treatment, and prognosis of patients treated for CS due to AMR. Patients alive after AMR were followed to analyze recurrences of AMR, graft function, and cardiac allograft vasculopathy (CAV). RESULTS: Seventeen patients met the inclusion criteria. Patients were mostly males (70%). Median age at diagnosis was 56 years, and median time between heart transplantation and AMR was 21 months. AMR was mostly due to high-level de novo class II DSA. Only 2 patients had past history of biopsy-proven AMR. Despite aggressive immunosuppressive therapies, in-hospital and 1-year mortality were as high as 76% and 82%, respectively. Four patients were discharged from hospital. Two of them were diagnosed with recurrent subclinical AMR: one died suddenly and the other presented rapidly progressive CAV. CONCLUSION: CS due to AMR occurred mostly in patients without history of AMR who developed de novo class II DSA. Despite aggressive conventional immunosuppressive therapies, prognosis after CS due to AMR was poor.

Does catastrophizing of bodily sensations maintain health-related anxiety? A 14-day daily diary study with longitudinal follow-up.

BACKGROUND: Health anxiety is common, impairing, and costly. The role of catastrophizing of bodily sensations (i.e. rumination about, overconcern with, and intolerance of bodily sensations) in maintaining health-related anxiety (i.e. anxiety about perceived health problems) is important, but understudied, in the health anxiety literature. AIMS: The present study investigates the role of catastrophizing of bodily sensations as a maintenance factor for health-related anxiety over time. METHOD: Undergraduates (n = 226 women; n = 226 men) completed a baseline assessment, 14-day daily diary study, and 14-day longitudinal follow-up. RESULTS: Path analysis indicated catastrophizing of bodily sensations maintains health-related anxiety from one month to the next in both men and women. CONCLUSIONS: The present study bridges an important gap between theory and evidence. Results support cognitive behavioral theories and extend cross-sectional research asserting catastrophizing of bodily sensations maintains health-related anxiety over time. A cyclical, self-perpetuating pattern was observed in the present study wherein catastrophizing of bodily sensations and health-related anxiety contribute to one another over time. Results also suggest targeting catastrophizing of bodily sensations may reduce health-related anxiety.

Chronic rejection triggers the development of an aggressive intragraft immune response through recapitulation of lymphoid organogenesis.

The unwarranted persistence of the immunoinflammatory process turns this critical component of the body's natural defenses into a destructive mechanism, which is involved in a wide range of diseases, including chronic rejection. Performing a comprehensive analysis of human kidney grafts explanted because of terminal chronic rejection, we observed that the inflammatory infiltrate becomes organized into an ectopic lymphoid tissue, which harbors the maturation of a local humoral immune response. Interestingly, intragraft humoral immune response appeared uncoupled from the systemic response because the repertoires of locally produced and circulating alloantibodies only minimally overlapped. The organization of the immune effectors within adult human inflamed tissues recapitulates the biological program recently identified in murine embryos during the ontogeny of secondary lymphoid organs. When this recapitulation was incomplete, intragraft B cell maturation was impeded, limiting the aggressiveness of the local humoral response. Identification of the molecular checkpoints critical for completion of the lymphoid neogenesis program should help develop innovative therapeutic strategies to fight chronic inflammation.

Preexisting donor-specific HLA antibodies predict outcome in kidney transplantation.

The clinical importance of preexisting HLA antibodies at the time of transplantation, identified by contemporary techniques, is not well understood. We conducted an observational study analyzing the association between preexisting donor-specific HLA antibodies (HLA-DSA) and incidence of acute antibody-mediated rejection (AMR) and survival of patients and grafts among 402 consecutive deceased-donor kidney transplant recipients. We detected HLA-DSA using Luminex single-antigen assays on the peak reactive and current sera. All patients had a negative lymphocytotoxic cross-match test on the day of transplantation. We found that 8-year graft survival was significantly worse (61%) among patients with preexisting HLA-DSA compared with both sensitized patients without HLA-DSA (93%) and nonsensitized patients (84%). Peak HLA-DSA Luminex mean fluorescence intensity (MFI) predicted AMR better than current HLA-DSA MFI (P = 0.028). As MFI of the highest ranked HLA-DSA detected on peak serum increased, graft survival decreased and the relative risk for AMR increased: Patients with MFI >6000 had >100-fold higher risk for AMR than patients with MFI <465 (relative risk 113; 95% confidence interval 31 to 414). The presence of HLA-DSA did not associate with patient survival. In conclusion, the risk for both AMR and graft loss directly correlates with peak HLA-DSA strength. Quantification of HLA antibodies allows stratification of immunologic risk, which should help guide selection of acceptable grafts for sensitized patients.

[Lymphoid neogenesis and lymphangiogenesis: two newcomers in the pathophysiology of chronic rejection]. / Néogenèse lymphoïde et lymphangiogenèse: deux nouveaux mécanismes impliqués dans la physiopathologie du rejet chronique.

Chronic rejection is one of the main causes of late allograft failure and no therapy is currently available to prevent efficiently its development. Improving the comprehension of the mechanisms involved in the pathophysiology of chronic rejection is a mandatory step to propose innovative therapies that would prolong grafts' survival. Using the rat aortic interposition model of chronic vascular rejection, we have demonstrated that the intragraft inflammatory infiltrate progressively organized itself into a functional ectopic lymphoid tissue (tertiary lymphoid organ) supporting the local synthesis of alloantibody. Thus, during chronic rejection the graft is at the same time the target and the site of elaboration of the humoral allo-immune response. This hypothesis has been confirmed in the clinical setting by the analysis of human grafts (kidneys, hearts and lungs) removed for terminal failure due to chronic rejection. This lymphoid neogenesis process, previously identified in other chronic inflammatory diseases, occurs with a strikingly high frequency in chronically rejected grafts, suggesting that an additional mechanism synergizes to initiate the development of tertiary lymphoid organs during chronic rejection. We propose that the defective lymphatic drainage of chronically rejected organs triggers lymphoid neogenesis and we discuss the complex crosstalk between lymphoid neogenesis and lymphangiogenesis that takes place during chronic rejection.

Favorable Outcome of an Exclusively Posttransplant Prophylactic Strategy After Heart Transplantation in Recipients With High Immunological Risk.

BACKGROUND: Management of the increasing number of sensitized heart transplant candidates has become a recurrent issue. Rather than using pretransplant desensitization therapies, we used a posttransplant prophylactic strategy. Our aim was to describe outcomes in transplant recipients with preformed donor-specific anti-HLA antibodies (pfDSA) managed with this strategy. METHODS: A posttransplant protocol was applied to patients transplanted with pfDSA, consisting of perioperative management of DSA (polyvalent immunoglobulins +/- perioperative plasmapheresis sessions, according to DSA level, as well as induction therapy) and systematic treatment of subsequent antibody-mediated rejection (AMR), even when subclinical. We performed a retrospective analysis of this prospective protocol. The study included all consecutive first recipients of a noncombined heart transplant performed between 2009 and 2015 at our center. The primary endpoint was all-cause mortality. Secondary endpoints included primary graft dysfunction, early posttransplant bleeding, rejection, and cardiac allograft vasculopathy-free survival. RESULTS: A total of 523 patients were studied, including 88 (17%) and 194 (37%) transplanted with DSA mean fluorescence intensity (MFI) of 500 to 1000 and greater than 1000, respectively. The median follow-up period was 4.06 years. Survival was not significantly different between groups. Rejection-free survival was worse in patients with pfDSA MFI >1000, evidenced by a fourfold increase in the risk of antibody-mediated rejection. The incidence of primary graft dysfunction and cardiac allograft vasculopathy-free survival did not significantly differ between groups. Perioperative plasmapheresis increased the risk for transfusion of packed red blood cells. CONCLUSIONS: This exclusively posttransplant prophylactic strategy achieved favorable outcomes in heart transplant recipients with pfDSA.

B cell survival in intragraft tertiary lymphoid organs after rituximab therapy.

BACKGROUND: Rituximab is emerging as a potent therapeutic option in chronic inflammatory diseases associated with a prominent humoral component. Recent studies have demonstrated that chronic inflammatory infiltrate organize progressively themselves into ectopic lymphoid tissues (tertiary lymphoid organs; TLOs) supporting a local humoral immune response. In the present study, we evaluated the impact of rituximab therapy on TLOs associated with chronic active antibody-mediated rejection, a prototypic humoral chronic inflammatory condition. METHODS: Renal allografts removed for terminal chronic rejection were prospectively collected in four transplantation centers over 4 years. Among 38 grafts collected, two were explanted after rituximab therapy for chronic active antibody-mediated rejection. Clinical characteristics and circulating B cell count were recorded for these two patients. The composition and the microarchitecture of the inflammatory infiltrate were analyzed by flow cytometry and immunohistochemistry. Organotypic cultures were performed to evaluate the intragraft production of alloantibody. Levels of expression of BAFF (Blys, CD257) were evaluated by quantitative reverse transcriptase-polymerase chain reaction. RESULTS: Despite the complete depletion of circulating B cells in peripheral blood, TLOs were evidenced in the interstitium of both explanted grafts. Their functionality was assessed by the demonstration of a persistent local production of alloantibody. BAFF, a potent survival factor for B cells, was found to be overexpressed (both at the gene and the protein levels) in chronically rejected grafts when compared with normal kidneys and lymph nodes. CONCLUSIONS: In certain patients, inflammatory microenvironment provides BAFF-dependent paracrine survival signal to B-cells in TLOs, allowing them to escape rituximab-induced apoptosis, thereby thwarting therapeutic efficiency.

Analysis of Transfusion-Related Acute Lung Injury and Possible Transfusion-Related Acute Lung Injury Reported to the French Hemovigilance Network From 2007 to 2013.

Using the French Hemovigilance Network database from 2007 to 2013, we provide information on demographics, incidence, and risk factors of reported transfusion-related acute lung injury (TRALI) and possible TRALI, analyze TRALI mitigation efforts for fresh frozen plasma and platelet concentrates, and consider the impact of platelet additive solutions on TRALI incidence. We applied the Toronto consensus conference definitions for TRALI and possible TRALI. Two TRALI subgroups were considered: "antibody positive" when a donor has human leukocyte antigen (class I or II) and/or human neutrophil antigen antibodies and the recipient has cognate antigen, and "antibody negative" when immunological investigation is negative or not done. The analysis targeted 378 cases, divided into antibody-positive TRALI (n=75), antibody-negative TRALI (n=100), and possible TRALI (n=203). TRALI patients were younger and received more blood components than the general population of transfused patients. Moreover, we identified the following clinical conditions where patients seemed to be at higher risk to develop TRALI: postpartum hemorrhage, acute myeloid leukemia, liver transplantation, allogeneic and autologous hematopoietic stem cells transplantation, polytrauma, and thrombotic microangiopathy. Policy measures intended to reduce antibody-positive TRALI were found effective for apheresis platelet concentrates and fresh frozen plasma but not for whole blood-derived platelet concentrates. The use of platelet additive solutions was associated with a significant reduction in the incidence of TRALI following transfusion of buffy coat-derived platelet concentrates but not following transfusion of apheresis platelets. Our data reinforce the concept that possible TRALI and TRALI, as defined in the Canadian consensus conference, share many characteristics. No specific policy measures are currently directed at mitigation of possible TRALI despite its impact on transfusion safety. Despite TRALI mitigation measures, the overall incidence of TRALI cases reported to the French Hemovigilance system was not significantly reduced. Therefore, additional research is needed to reduce, if not eradicate, all TRALI categories.

Are perfectionistic concerns an antecedent of or a consequence of binge eating, or both? A short-term four-wave longitudinal study of undergraduate women.

The perfectionism model of binge eating (PMOBE) posits perfectionistic concerns are a vulnerability factor for binge eating. And evidence indicates perfectionistic concerns and binge eating correlate positively. However, the direction of this relationship is seldom studied. Accordingly, it is unclear whether perfectionistic concerns represent an antecedent of binge eating (a vulnerability effect with perfectionistic concerns predicting increases in binge eating), a consequence of binge eating (a complication effect with binge eating predicting increases in perfectionistic concerns), or both (reciprocal relations with perfectionistic concerns predicting increases in binge eating and vice versa). To address these questions, we studied 200 undergraduate women using a 4-week, 4-wave cross-lagged longitudinal design. Consistent with the PMOBE, perfectionistic concerns predicted increased binge eating (vulnerability effect). But, binge eating did not predict increased perfectionistic concerns (complication effect). Findings support the long-held theory that perfectionistic concerns are part of the premorbid personality of women vulnerable to binge eating.

Characteristics of Donor-Specific Antibodies Associated With Antibody-Mediated Rejection in Lung Transplantation.

Although donor-specific anti-human leukocyte antigen (HLA) antibodies (DSAs) are frequently found in recipients after lung transplantation (LT), the characteristics of DSA which influence antibody-mediated rejection (AMR) in LT are not fully defined. We retrospectively analyzed 206 consecutive LT patients of our center (2010-2013). DSAs were detected by using luminex single antigen beads assay and mean fluorescence intensity was assessed. Within the study population, 105 patients had positive DSA. Patients with and without AMR (AMRPos, n = 22, and AMRNeg, n = 83, respectively) were compared. AMRPos patients had significantly greater frequencies of anti-HLA DQ DSA (DQ DSA) than AMRNeg patients (95 vs 58%, respectively, p < 0.0001). Compared to AMRNeg patients, AMRPos patients had higher DQ DSA sum MFI [7,332 (2,067-10,213) vs 681 (0-1,887), p < 0.0001]. DQ DSA when associated with AMR, had more frequent graft loss and chronic lung allograft dysfunction (CLAD). These data suggest (i) that DSA characteristics clearly differ between AMRPos and AMRNeg patients and (ii) the deleterious impact of DQ DSA on clinical outcome.

Enhancement motives moderate the relationship between high-arousal positive moods and drinking quantity: Evidence from a 22-day experience sampling study.

INTRODUCTION AND AIMS: Individuals who consume alcohol may be distinguished by their drinking motives. Enhancement motives involve drinking to enhance positive moods. Research on the moderating effect of enhancement motives on the within-person relation between daily positive mood and drinking has not differentiated between high- (e.g. hyper) and low-arousal (e.g. cheerful) positive moods. The present study addressed this limitation. We hypothesised that enhancement motives would positively moderate the relationship between mid-afternoon high-arousal positive mood and evening drinking. DESIGN AND METHODS: Using a palm pilot-based experience sampling design, 143 undergraduate drinkers answered daily surveys assessing positive mood (mid-afternoon) and drinks (evening) for 22 consecutive days. RESULTS: As hypothesised, enhancement motives strengthened the relation between high-arousal positive moods and drinking. Upon closer examination, the mood-drinking slope for those high in enhancement motives was unexpectedly flat, whereas the mood-drinking slope for those low in enhancement motives was negative. DISCUSSION AND CONCLUSIONS: We demonstrated that high enhancement-motivated drinkers exhibit a high, stable drinking level, regardless of the intensity of their high-arousal positive mood. In contrast, low enhancement-motivated drinkers decrease their drinking when in a high-arousal positive mood state. Clinicians may be able to help reduce heavy alcohol consumption in enhancement-motivated drinkers by teaching them to reduce their drinking when in a high-arousal positive mood state.

Lung transplantation in patients with pretransplantation donor-specific antibodies detected by Luminex assay.

BACKGROUND: New methods of solid-phase assays, such as Luminex assay, with high sensitivity in detecting anti-human leukocyte antigen (HLA) antibodies (Abs), have increased the proportion of sensitized candidates waiting for lung transplantation (LTx). However, how to apply these results clinically during graft allocation is debated: strict exclusion of candidates with Luminex-positive results can lead to lost opportunities for Tx. We retrospectively analyzed the clinical impact of pre-LTx Luminex-detected Abs on post-LTx outcomes for patients who underwent LTx before the availability of Luminex assay. METHODS: We analyzed data for 56 successive patients who underwent LTx before 2008 and were considered to not have anti-HLA Abs by then-available methods of detection at the date of their LTx. Pre-LTx sera from these patients were retested by Luminex assay. Using log-rank test, freedom from bronchiolitis obliterans syndrome (BOS) and graft survival were compared between patients with and without pre-LTx Luminex-detected anti-HLA Abs classes I and II and donor-specific Abs (DSA) classes I and II. RESULTS: Freedom from bronchiolitis obliterans syndrome was lower, and mortality was higher for patients with than those without pre-LTx Luminex-detected DSA class II (P=0.004 and P=0.007, respectively) but did not differ for patients with and without DSA class I or anti-HLA Abs class I or II. CONCLUSIONS: It suggests to avoid attributing graft with forbidden antigens to sensitized candidates with Luminex-detected DSA class II and to evaluate the role of specific posttransplantation protocols for LTx candidates who require emergency LTx.

Immune responses elicited in tertiary lymphoid tissues display distinctive features.

During chronic inflammation, immune effectors progressively organize themselves into a functional tertiary lymphoid tissue (TLT) within the targeted organ. TLT has been observed in a wide range of chronic inflammatory conditions but its pathophysiological significance remains unknown. We used the rat aortic interposition model in which a TLT has been evidenced in the adventitia of chronically rejected allografts one month after transplantation. The immune responses elicited in adventitial TLT and those taking place in spleen and draining lymph nodes (LN) were compared in terms of antibody production, T cell activation and repertoire perturbations. The anti-MHC humoral response was more intense and more diverse in TLT. This difference was associated with an increased percentage of activated CD4+ T cells and a symmetric reduction of regulatory T cell subsets. Moreover, TCR repertoire perturbations in TLT were not only increased and different from the common pattern observed in spleen and LN but also "stochastic," since each recipient displayed a specific pattern. We propose that the abnormal activation of CD4+ T cells promotes the development of an exaggerated pathogenic immune humoral response in TLT. Preliminary findings suggest that this phenomenon i) is due to a defective immune regulation in this non-professional inflammatory-induced lymphoid tissue, and ii) also occurs in human chronically rejected grafts.