[Cardiac sarcoidosis revealed by recurrent ventricular tachycardia]. / Tachycardie ventriculaire récidivante révélant une sarcoïdose cardiaque.

Sarcoidosis is an inflammatory disease whose diagnosis is suggested by clinical and paraclinical signs and confirmed by histological evidence showing granulomatosis without caseous necrosis. The clinical presentation is sometimes misleading and the diagnosis difficult to confirm. We report here the case of a young woman with cardiac sarcoidosis of difficult diagnosis, revealed by a myocardial infarction with normal coronary angiography and recurrent ventricular tachycardia. Multimodal imaging, combined with left ventricular endomyocardial biopsies guided by electrophysiological analysis and endocavitary mapping, finally confirmed the diagnosis, and allowed effective medical treatment.

Diagnostic yield, safety and therapeutic consequences of myocardial biopsy in clinically suspected fulminant myocarditis unweanable from mechanical circulatory support.

BACKGROUND: Fulminant myocarditis is a rare and severe disease whose definite and etiological diagnoses rely on pathological examination. Albeit, myocardial biopsy can be associated with significant morbidity and mortality, its therapeutic consequences are unclear. We conducted a study to determine the diagnostic yield, the safety and the therapeutic consequences of myocardial biopsy in patients with fulminant clinically suspected myocarditis unweanable from mechanical circulatory support (MCS). METHODS: Monocenter, retrospective, observational cohort study in a 26-bed French tertiary ICU between January 2002 and February 2019. Inclusion of all fulminant clinically suspected myocarditis patients undergoing in-ICU myocardial biopsy while being on MCS. The primary endpoint was the proportion of patients classified as definite myocarditis using Bonaca criteria before and after including myocardial biopsy results. RESULTS: Forty-seven patients (median age 41 [30-47], female 53%) were included: 55% died before hospital discharge, 34% could be bridged-to-recovery and 15% bridged-to-transplant. Myocardial biopsy was endomyocardial or surgical in 36% and 64% cases respectively. Tamponade requiring emergency pericardiocentesis occurred in 29% patients after endomyocardial biopsy. After adding the biopsy results in the Bonaca classification algorithm the percentage of definite myocarditis raised from 13 to 55% (p < 0.0001). The rate of biopsy-related treatments modifications was 13%, leading to patients' recovery in only 4% patients. CONCLUSIONS: In clinically suspected myocarditis unweanable from MCS, myocardial biopsy increased the rate of definite myocarditis but was associated with a low rate of treatment modification and a significant proportion of adverse events. We believe the benefit/risk ratio of myocardial biopsy should be more carefully weighted in these frail and selected patients than suggested by actual guidelines. Further prospective studies are now needed to determine its value in patients under MCS.

Abatacept/Ruxolitinib and Screening for Concomitant Respiratory Muscle Failure to Mitigate Fatality of Immune-Checkpoint Inhibitor Myocarditis.

Immune-checkpoint-inhibitor (ICI)-associated myotoxicity involves the heart (myocarditis) and skeletal muscles (myositis), which frequently occur concurrently and are highly fatal. We report the results of a strategy that included identification of individuals with severe ICI myocarditis by also screening for and managing concomitant respiratory muscle involvement with mechanical ventilation, as well as treatment with the CTLA4 fusion protein abatacept and the JAK inhibitor ruxolitinib. Forty cases with definite ICI myocarditis were included with pathologic confirmation of concomitant myositis in the majority of patients. In the first 10 patients, using recommended guidelines, myotoxicity-related fatality occurred in 60%, consistent with historical controls. In the subsequent 30 cases, we instituted systematic screening for respiratory muscle involvement coupled with active ventilation and treatment using ruxolitinib and abatacept. The abatacept dose was adjusted using CD86 receptor occupancy on circulating monocytes. The myotoxicity-related fatality rate was 3.4% (1/30) in these 30 patients versus 60% in the first quartile (P < 0.0001). These clinical results are hypothesis-generating and need further evaluation. SIGNIFICANCE: Early management of respiratory muscle failure using mechanical ventilation and high-dose abatacept with CD86 receptor occupancy monitoring combined with ruxolitinib may be promising to mitigate high fatality rates in severe ICI myocarditis. See related commentary by Dougan, p. 1040. This article is highlighted in the In This Issue feature, p. 1027.

Clinical Prediction Model for Antibody-Mediated Rejection: A Strategy to Minimize Surveillance Endomyocardial Biopsies After Heart Transplantation.

BACKGROUND: In heart transplantation, antibody-mediated rejection (AMR) is a major contributor to patient morbidity and mortality. Multiple routine endomyocardial biopsies (EMB) remain the gold standard to detect AMR, but this invasive procedure suffers from many limitations. We aimed to develop and validate an AMR risk model to improve individual risk stratification of AMR. METHODS: Heart recipients from 2 referral transplant centers, Cedars-Sinai (US) and Pitié-Salpêtrière (France), were included from 2012 to 2019. Database included detailed clinical, immunologic, imaging, and histological parameters. The US cohort was randomly distributed in a derivation (2/3) and in a test set (1/3). The primary end point was biopsy-proven AMR. A mixed effect logistic regression model with a random intercept was applied to identify variables independently associated with AMR. Simulation analyzes were performed. RESULTS: The US and French cohorts comprised a total of 1341 patients, representing 12 864 EMB. Overall, 490 AMR episodes were diagnosed (3.8% of EMB). Among the 26 potential determinants of AMR, 5 variables showed independent association: time post-transplant (P<0.001), pretransplant sensitizing event (P=0.001), circulating donor-specific anti-human leukocyte antigen antibody (P=0.001), graft dysfunction (P=0.004), and prior history of definite AMR (P<0.001). In the US test set, the calibration and the discrimination of the model were accurate (area under the curve, 0.79 [95% CI, 0.78-0.81]). Those results were confirmed in the external validation cohort (area under the curve, 0.78 [95% CI, 0.77-0.79]) and reinforced by various sensitivity analyses. The model also showed good performance to predict overall cause of rejection. Simulation models revealed that the AMR risk model could safely reduce the number of EMB. CONCLUSIONS: Our results support the use of the AMR risk model as a clinical decision tool to minimize the number of routine EMB after heart transplantation.

Correlation Between Microvascular Inflammation in Endomyocardial Biopsies and Rejection Transcripts, Donor-specific Antibodies, and Graft Dysfunction in Antibody-mediated Rejection.

BACKGROUND: The pathology-based diagnosis of cardiac antibody-mediated rejection (AMR) relies on the 2013 International Society for Heart and Lung Transplantation Working Formulation, in which microvascular inflammation (MVI) is considered as present or absent regardless of its extent. This work assessed the biological and clinical value of a semiquantitative evaluation of the extent of MVI in endomyocardial biopsies (EMBs). METHODS: We retrospectively graded the extent of MVI in 291 EMB from 291 patients according to a 4-point scale in which MVI scores of 0, 1, 2, and 3 represented 0%, 1%-10%, 11%-50%, and >50% of the myocardial area, respectively. We analyzed the association between the MVI score and tissue rejection molecular activity assessed by microarrays or reverse transcriptase multiplex ligation-dependent probe amplification, current pathology classification (pathologic AMR [pAMR]), anti-HLA donor-specific antibodies, and graft dysfunction. RESULTS: Overall, 172 (59.1%), 33 (11.4%), 42 (14.4%), and 44 (15.1%) EMB were given MVI scores of 0, 1, 2, and 3, respectively. pAMR1(H+) and pAMR2/3 categories were found to be heterogeneous in terms of MVI score. Acute cellular rejection grades did not influence the MVI score. In both molecular approaches, we observed a stepwise increase in the expression of AMR-related transcripts with increasing MVI scores, independent of the C4d or CD68 status (P < 0.001). Both the frequency and mean fluorescence intensity of donor-specific antibodies gradually increased with the MVI score (P < 0.001). Acute graft dysfunction was more frequent in MVI score 3 (P < 0.001). CONCLUSIONS: The intensity of MVI in EMB, based on a semiquantitative evaluation of its extent, has biological and clinical importance.

Impact of Sex in the Efficacy of Perioperative Desensitization Procedures in Heart Transplantation: A Retrospective Cohort Study.

Background: Sensitized patients, i.e. recipients with preformed donor-specific HLA antibodies (pfDSA), are at high-risk of developing antibody-mediated rejections (AMR) and dying after heart transplantation (HTx). Perioperative desensitization procedures are associated with better outcomes but can cause sensitization, which may influence their efficacy. Methods: In sensitized patients (pfDSA>1000 mean immunofluorescence (MFI) units), we assessed the effect of perioperative desensitization by comparing treated patients to a historical control cohort. Multivariable survival analyses were performed on the time to main outcome, a composite of death and biopsy-proven AMR with 5-year follow-up. Results: The study included 68 patients: 31 control and 37 treated patients. There was no difference in preoperative variables between the two groups, including cumulative pfDSA [4026 (1788;8725) vs 4560 (3162;13392) MFI units, p=0.28]. The cause of sensitization was pregnancy in 24/68, 35.3%, transfusion in 61/68, 89.7%, and previous HTx in 4/68, 5.9% patients. Multivariable analysis yielded significant protective association between desensitization and events (adjusted (adj.) hazard ratio (HR)=0.44 (95% confidence interval (95CI)=0.25-0.79), p=0.006) and deleterious association between cumulative pfDSA and events [per 1000-MFI increase, adj.HR=1.028 (1.002-1.053), p=0.031]. There was a sex-difference in the efficacy of desensitization: in men (n=35), the benefit was significant [unadj.HR=0.33 (95CI=0.14-0.78); p=0.01], but not in women (n=33) [unadj.HR=0.52 (0.23-1.17), p=0.11]. In terms of the number of patients treated, in men, 2.1 of patients that were treated prevented 1 event, while in women, 3.1 required treatment to prevent 1 event. Conclusion: Perioperative desensitization was associated with fewer AMR and deaths after HTx, and efficacy was more pronounced in men than women.

Immune Checkpoint Inhibitor Myocarditis With Normal Cardiac Magnetic Resonance Imaging: Importance of Cardiac Biopsy and Early Diagnosis.

Immune checkpoint inhibitors (ICIs) have improved the management and the prognosis of patients with cancer but are associated with an increased risk of toxicities that can affect every organ. ICI-associated myocarditis has a low incidence (< 1%) but a high fatality rate (30%-50%). Herein we report a patient treated with ICI admitted for suspicion of myocarditis. Cardiac magnetic resonance imaging (cMRI) was normal. An endomyocardial biopsy (EMB) was in favour of ICI-related myocarditis with cardiac lymphohistiocytic infiltrate. This case highlights the role of a systematic evaluation with electrocardiography and troponin and the potential value of EMB in patients without a suggestive cMRI.

Quadritherapy vs standard tritherapy immunosuppressant regimen after heart transplantation: A propensity score-matched cohort analysis.

After heart transplant, adding everolimus (EVL) to standard immunosuppressive regimen mostly relies on converting calcineurin inhibitors (CNIs) into EVL. The aim of this study was to describe the effects of combining low-dose EVL and CNIs in maintenance immunosuppression regimen (quadritherapy) and compare it with standard tritherapy associating standard-dose CNIs, mycophenolate mofetil, and corticosteroids. In the 3-year registry cohort of heart transplanted patients, those who received quadritherapy were compared with those who received tritherapy. EVL was added after 3 months posttransplant. Three analyses were performed to control for confounders: propensity score matching, multivariable survival, and inverse probability score weighting analyses. Among 213 patients who were included (75 with quadritherapy), propensity score matching selected 64 unique pairs of patients with similar characteristics. In the matched cohort (n = 128), quadritherapy was associated with fewer deaths (3 [4.7%] vs 17 [21.9%], P = .007) and biopsy-proven acute rejections (15 [23.4%] vs 31 [48.4%], P = .002). These results were confirmed in the overall cohort (n = 213), after multivariable and inverse probability score weighting analyses. Renal function and donor-specific HLA-antibodies remained similar in both groups. Low-dose combination quadritherapy was associated with fewer deaths and rejections, compared with standard immunosuppression tritherapy.

Microvasculature partial endothelial mesenchymal transition in early posttransplant biopsy with acute tubular necrosis identifies poor recovery renal allografts.

Acute tubular necrosis (ATN), a frequent histopathological feature in the early post-renal transplant biopsy, affects long-term graft function. Appropriate markers to identify patients at risk of no or incomplete recovery after delayed graft function are lacking. In this study, we first included 41 renal transplant patients whose biopsy for cause during the first month after transplantation showed ATN lesions. Using partial microvasculature endothelial (fascin, vimentin) and tubular epithelial (vimentin) to mesenchymal transition markers, detected by immunohistochemistry, we found a significant association between partial endothelial to mesenchymal transition and poor graft function recovery (Spearman's rho = -0.55, P = .0005). Transforming growth factor-ß1 was strongly expressed in these phenotypic changed endothelial cells. Extent of ATN was also correlated with short- and long-term graft dysfunction. However, the association of extensive ATN with long-term graft dysfunction (24 months posttransplant) was observed only in patients with partial endothelial to mesenchymal transition marker expression in their grafts (Spearman's rho = -0.64, P = .003), but not in those without. The association of partial endothelial to mesenchymal transition with worse renal graft outcome was confirmed on 34 other early biopsies with ATN from a second transplant center. Our results suggest that endothelial cell activation at the early phase of renal transplantation plays a detrimental role.

Comprehensive Molecular and Pathologic Evaluation of Transitional Mesothelioma Assisted by Deep Learning Approach: A Multi-Institutional Study of the International Mesothelioma Panel from the MESOPATH Reference Center.

INTRODUCTION: Histologic subtypes of malignant pleural mesothelioma are a major prognostic indicator and decision denominator for all therapeutic strategies. In an ambiguous case, a rare transitional mesothelioma (TM) pattern may be diagnosed by pathologists either as epithelioid mesothelioma (EM), biphasic mesothelioma (BM), or sarcomatoid mesothelioma (SM). This study aimed to better characterize the TM subtype from a histological, immunohistochemical, and molecular standpoint. Deep learning of pathologic slides was applied to this cohort. METHODS: A random selection of 49 representative digitalized sections from surgical biopsies of TM was reviewed by 16 panelists. We evaluated BAP1 expression and CDKN2A (p16) homozygous deletion. We conducted a comprehensive, integrated, transcriptomic analysis. An unsupervised deep learning algorithm was trained to classify tumors. RESULTS: The 16 panelists recorded 784 diagnoses on the 49 cases. Even though a Kappa value of 0.42 is moderate, the presence of a TM component was diagnosed in 51%. In 49% of the histological evaluation, the reviewers classified the lesion as EM in 53%, SM in 33%, or BM in 14%. Median survival was 6.7 months. Loss of BAP1 observed in 44% was less frequent in TM than in EM and BM. p16 homozygous deletion was higher in TM (73%), followed by BM (63%) and SM (46%). RNA sequencing unsupervised clustering analysis revealed that TM grouped together and were closer to SM than to EM. Deep learning analysis achieved 94% accuracy for TM identification. CONCLUSION: These results revealed that the TM pattern should be classified as non-EM or at minimum as a subgroup of the SM type.

Safety and effectiveness of transjugular renal biopsy for systemic lupus erythematosus and antiphospholipid antibody syndrome patients taking antithrombotics.

BACKGROUND: Renal biopsy is the cornerstone of systemic lupus erythematosus (SLE) nephritis and antiphospholipid syndrome (APS) nephropathy management. However, transcutaneous renal biopsy (TCRB) is hampered by the antithrombotic treatment frequently prescribed for those diseases. Transjugular renal biopsy (TJRB) offers an attractive alternative for patients at increased risk of bleeding. The primary objective of the study was to describe the safety profile and diagnostic performance of TJRB in SLE and APS patients. METHODS: All SLE and/or APS patients who underwent a renal biopsy in our department (between January 2004 and October 2016) were retrospectively reviewed. Major complications were death, haemostasis nephrectomy, renal artery embolization, red blood cell transfusion, sepsis and vascular thrombosis; macroscopic haematuria, symptomatic perirenal/retroperitoneal bleeding and renal arteriovenous fistula without artery embolization were considered as minor complications. RESULTS: Two hundred and fifty-six TJRBs-119 without antithrombotics (untreated), 69 under aspirin and 68 on anticoagulants and 54 TCRBs without antithrombotics-were analysed. Their major and minor complication rates, respectively, did not differ significantly for the four groups: 0 and 8% for untreated TJRBs, 1 and 6% for aspirin-treated, 6 and 10% for anticoagulant-treated and 2 and 2% for TCRBs. The number of glomeruli sampled and the biopsy contribution to establishing a histological diagnosis was similar for the four groups. CONCLUSIONS: TJRBs obtained from SLE and APS patients taking antithrombotics had diagnostic yields and safety profiles similar to those of untreated TCRBs. Thus, TJRB should be considered for SLE and APS patients at risk of bleeding.

Rituximab-associated Vasculitis Flare: Incidence, Predictors, and Outcome.

OBJECTIVE: To report the incidence, predictors, and outcome of rituximab (RTX)-associated autoimmune disease flare. METHODS: We conducted a retrospective study in a tertiary referral center from 2005 to 2015. Disease flare was defined as the onset of a new organ involvement or worsening of autoimmune disease within 4 weeks following RTX. RESULTS: Among the 185 patients, we identified 7 disease flares (3.4%). All were due to type II mixed cryoglobulinemia vasculitis. Vasculitis flare occurred after a median time of 8 days (range 2-16) following RTX infusion and included acute kidney insufficiency (n = 7), purpura with cutaneous (n = 7), gastrointestinal (GI) tract involvement (n = 4), and myocarditis (n = 1). Patients with RTX-associated cryoglobulinemia vasculitis flare had these conditions more frequently: renal involvement (p = 0.0008), B cell lymphoproliferation (p = 0.015), higher level of cryoglobulin (2.1 vs 0.4 g/l, p = 0.0004), and lower level of C4 (0.02 vs 0.05, p = 0.023) compared to patients without flare after RTX (n = 43). Four patients (57%) died after a median time of 3.3 months. The 1-year survival rate was poorer in patients with vasculitis flare after RTX compared to their negative counterpart [43% (95% CI 18-100) vs 97% (95% CI 92-100), p < 0.001]. Immunofluorescence analysis of kidney biopsy in patients with worsening RTX-associated vasculitis highlighted the presence of RTX-, IgM-, and IgG1-positive staining of endomembranous deposits and thrombi within kidney lesions. CONCLUSION: RTX-associated cryoglobulinemia vasculitis flare is associated with high mortality rate. We provided evidence that kidney lesions are due to immune complex deposition and to glomerular obstruction by cryoglobulinemia and RTX.

Reverse transcriptase multiplex ligation-dependent probe amplification in endomyocardial biopsies for the diagnosis of cardiac allograft rejection.

BACKGROUND: Molecular biology has emerged as a potential companion to histology for the diagnosis of rejection after heart transplantation. Reverse transcriptase multiplex ligation-dependent probe amplification (RT-MLPA) is a technique of targeted gene expression analysis suitable for formalin-fixed paraffin-embedded (FFPE) biopsies. Our aim was to assess RT-MLPA for the diagnosis of allograft rejection in heart transplantation. METHODS: We performed a cross-sectional, case-control, multicenter study. After the selection of a 14-transcript panel (endothelial burden, Natural killer cells, interferon-γ pathway, effector T-cells, and antigen presentation), RT-MLPA was applied to 183 FFPE endomyocardial biopsies (EMB), randomized into a training (n = 113) and a validation (n = 70) series. A two-step class prediction analysis was developed (Linear prediction score-LPS1: rejection vs non-rejection; LPS2: antibody-mediated rejection [AMR] vs acute cellular rejection [ACR]). A study of the agreement between pathology and RT-MLPA was performed. RESULTS: Overall, 48 ACR, 82 AMR, 5 mixed rejection, and 48 non-rejection EMBs were analyzed. Three molecular clusters were delineated by unsupervised hierarchical analysis (molecular non-rejection, ACR, and AMR). AMR was characterized by the high expression of CCL4, GNLY, FCGR3, CXCL11 and ACR by the high expression of CCL18 and ADAMdec. RT-MLPA and histopathology agreed in the final diagnosis in 82.2%, 67.7%, and 76.8% of the EMB in the test, validation, and overall cohort, respectively. Disagreement cases were more common in the case of histologic low-grade rejection and early post-transplant EMB. CONCLUSIONS: RT-MLPA is a suitable technique for targeted gene expression analysis on FFPE EMB with a good overall agreement with the histologic diagnosis of heart allograft rejection.

Transvenous Renal Biopsy of Critically Ill Patients: Safety and Diagnostic Yield.

OBJECTIVES: Transvenous renal biopsy is an alternative way to obtain kidney samples from patients with bleeding risk factors (e.g., antiplatelet therapy and anticoagulation or coagulation disorders). This study was undertaken to determine the safety and diagnostic yield of transvenous renal biopsy of critically ill patients. DESIGN: Monocenter, retrospective, observational cohort study. SETTING: A 26-bed French tertiary ICU. PATIENTS: All patients undergoing in-ICU transvenous renal biopsy between January 2002 and February 2018. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Eighty patients (male/female sex ratio, 0.95; mean ± SD age, 47.3 ± 18.3 yr) were included. A histologic diagnosis was obtained for 77 patients (96.3%), with acute tubular necrosis being the most frequent: 23 (29.9%). A potentially treatable cause was found for 47 patients (58.7%). The numbers of patients with 0, 1, 2, or 3 factors (i.e., antiplatelet therapy, thrombopenia [< 150 G/L], and preventive or curative anticoagulation) at the time of the biopsy were, respectively: seven (8.8%), 37 (46.2%), 31 (38.7%), and five (6.3%). Four (5%) and two (2.5%) patients, respectively, had renal hematoma and macroscopic hematuria; none required any specific treatment. Six patients (7.5%) died in-ICU, and 90-day mortality was 8 of 80 (10%). No death was related to transvenous renal biopsy, and median biopsy-to-death interval was 38 days (interquartile range, 19.7-86 d). CONCLUSIONS: Based on this cohort of ICU patients with acute kidney injury, transvenous renal biopsy was safe and obtained a high diagnostic yield for these selected critically ill patients, even in the presence of multiple bleeding risk factors.

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.

Renal failure during chemotherapy: renal biopsy for assessing subacute nephrotoxicity of pemetrexed.

BACKGROUND: Pemetrexed, a multitargeted antifolate cytotoxic agent, is currently used primarily in combination with cisplatin for metastatic non-small cell lung cancer and for malignant mesothelioma. Acute renal toxicity of pemetrexed has been recently described with polychemotherapy, in which the individual responsibility of each drug is difficult to establish. Only one recent report documents renal involvement in long-term exposed patients. CASE PRESENTATION: We report on a case of rapidly progressive nephropathy leading to the cessation of platinum salts and the secondary interruption of pemetrexed and bevacizumab. Acute tubular necrosis shown on the renal biopsy could potentially be due to pemetrexed. Persistent severe renal failure after the resumption of all drugs led to new treatment lines with gemcitabine (while the glomerular filtration rate was below 30 ml/min/1.73m2), then followed by Taxol. CONCLUSIONS: The optimal strategy with regard to renal complications in cancer patients is not clear. Acute or chronic loss in renal function generally leads to a new treatment line, possibly impairing the overall success of the treatment. The use of chemotherapy in patients with a glomerular filtration rate below 30 ml/min/1.73m2 is usually associated with an increased risk of side effects when not contraindicated by renal elimination of the drug.

Antineutrophil cytoplasmic antibody-associated vasculitides and IgG4-related disease: A new overlap syndrome.

OBJECTIVE: Atypical manifestations have been described in patients with ANCA-associated vasculitides (AAV), such as pachymeningitis, orbital mass or chronic periaortitis. Because these manifestations have been associated to the spectrum of IgG4-related disease (IgG4-RD), we hypothesized that both diseases could overlap. METHODS: We conducted a European retrospective multicenter observational study including patients fulfilling ACR and Chapel Hill criteria for AAV and IgG4-RD Comprehensive Diagnostic Criteria. RESULTS: Eighteen patients were included (median age 55.5years, 13 men). AAV and IgG4-RD were diagnosed concomitantly in 13/18 (72%) patients; AAV preceded IgG4-RD in 3/18 (17%) while IgG4-RD preceded AAV in 2/18 (11%). AAV diagnoses included granulomatosis with polyangiitis in 14 (78%), microscopic polyangiitis in 3 (17%), and eosinophilic granulomatosis with polyangiitis in one case. IgG4-RD diagnosis included definite IgG4-RD in 5 (28%) cases, probable IgG4-RD in 5 (28%) and possible IgG4-RD in 8 (44%). IgG4-RD manifestations were chronic periaortitis in 9/18 (50%) patients, orbital mass and tubulointerstitial nephritis in 4 (22%) cases, prevertebral fibrosis in 3 (17%), pachymeningitis and autoimmune pancreatitis in 2 (11%) cases. Patients required median number of 2 (range 0-4) lines of immunosuppressants in combination with glucocorticoids. During the follow-up (median 49,8months, range 17,25-108months), AAV manifestations relapsed in 10/18 (56%) cases and IgG4-RD lesions in 5/18 (28%). When used, mainly for relapses, rituximab showed response in all cases. CONCLUSION: AAV and IgG4-RD may overlap. Clinicians should consider that atypical manifestations during AAV could be related to IgG4-RD rather than to refractory granulomatous or vasculitic lesions.

Gene Expression Profiling for the Identification and Classification of Antibody-Mediated Heart Rejection.

BACKGROUND: Antibody-mediated rejection (AMR) contributes to heart allograft loss. However, an important knowledge gap remains in terms of the pathophysiology of AMR and how detection of immune activity, injury degree, and stage could be improved by intragraft gene expression profiling. METHODS: We prospectively monitored 617 heart transplant recipients referred from 4 French transplant centers (January 1, 2006-January 1, 2011) for AMR. We compared patients with AMR (n=55) with a matched control group of 55 patients without AMR. We characterized all patients using histopathology (ISHLT [International Society for Heart and Lung Transplantation] 2013 grades), immunostaining, and circulating anti-HLA donor-specific antibodies at the time of biopsy, together with systematic gene expression assessments of the allograft tissue, using microarrays. Effector cells were evaluated with in vitro human cell cultures. We studied a validation cohort of 98 heart recipients transplanted in Edmonton, AB, Canada, including 27 cases of AMR and 71 controls. RESULTS: A total of 240 heart transplant endomyocardial biopsies were assessed. AMR showed a distinct pattern of injury characterized by endothelial activation with microcirculatory inflammation by monocytes/macrophages and natural killer (NK) cells. We also observed selective changes in endothelial/angiogenesis and NK cell transcripts, including CD16A signaling and interferon-γ-inducible genes. The AMR-selective gene sets accurately discriminated patients with AMR from those without and included NK transcripts (area under the curve=0.87), endothelial activation transcripts (area under the curve=0.80), macrophage transcripts (area under the curve=0.86), and interferon-γ transcripts (area under the curve=0.84; P<0.0001 for all comparisons). These 4 gene sets showed increased expression with increasing pathological AMR (pAMR) International Society for Heart and Lung Transplantation grade (P<0.001) and association with donor-specific antibody levels. The unsupervised principal components analysis demonstrated a high proportion of molecularly inactive pAMR1(I+), and there was significant molecular overlap between pAMR1(H+) and full-blown pAMR2/3 cases. Endothelial activation transcripts, interferon-γ, and NK transcripts showed association with chronic allograft vasculopathy. The molecular architecture and selective AMR transcripts, together with gene set discrimination capacity for AMR identified in the discovery set, were reproduced in the validation cohort. CONCLUSIONS: Tissue-based measurements of specific pathogenesis-based transcripts reflecting NK burden, endothelial activation, macrophage burden, and interferon-γ effects accurately classify AMR and correlate with degree of injury and disease activity. This study illustrates the clinical potential of a tissue-based analysis of gene transcripts to refine diagnosis of heart transplant rejection.