RNA-based immunoglobulin repertoire sequencing is a new tool for the management of monoclonal gammopathy of renal (kidney) significance.

The diagnostic approach of monoclonal gammopathy of renal significance is based on the detection of a monoclonal immunoglobulin in the blood and urine, and the identification of the underlying clone through bone marrow and/or peripheral blood cytologic and flow cytometry analysis. However, the monoclonal component and its corresponding clone may be undetectable using these routine techniques. Since clone identification is the cornerstone for guiding therapy and assessing disease response, more sensitive methods are required. We recently developed a high-throughput sequencing assay from bone marrow mRNA encoding immunoglobulins (RACE-RepSeq). This technique provides both full-length V(D)J region (variable, diversity and joining genes that generate unique receptors as antigen receptors) of the monoclonal immunoglobulin and the dominant immunoglobulin repertoire. This allows analysis of mutational patterns, immunoglobulin variable gene frequencies and diversity due to somatic hypermutation. Here, we evaluated the diagnostic performance of RACE-RepSeq in 16 patients with monoclonal-associated kidney lesions, and low serum monoclonal immunoglobulin and free light chain levels at diagnosis. Bone marrow immunohistochemical analysis was negative in all 11 patients so tested and 7 of 12 patients had no detectable clone matching the kidney deposits using flow cytometry analysis. By contrast, RACE-RepSeq detected a dominant clonal light chain sequence of matched isotype with respect to kidney deposits in all patients. Thus, high throughput mRNA sequencing appears highly sensitive to detect subtle clonal disorders in monoclonal gammopathy of renal significance and suggest this novel approach could help improve the management of this kidney disease.

Immunoglobulin variable domain high-throughput sequencing reveals specific novel mutational patterns in POEMS syndrome.

Polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes (POEMS) syndrome is a rare multisystem disease resulting from an underlying plasma cell (PC) dyscrasia. The pathophysiology of the disease remains unclear, but the role of the monoclonal immunoglobulin (Ig) light chain (LC) is strongly suspected because of the highly restrictive usage of 2 λ variable (V) domains (IGLV1-40 and IGLV1-44) and the general improvement of clinical manifestations after PC clone-targeted treatment. However, the diagnostic value of Ig LC sequencing, especially in the case of incomplete forms of the disease, remains to be determined. Using a sensitive high-throughput Ig repertoire sequencing on RNA (rapid amplification of cDNA ends-based repertoire sequencing [RACE-RepSeq]), we detected a λ LC monoclonal expansion in the bone marrow (BM) of 83% of patients with POEMS syndrome, including some in whom BM tests routinely performed to diagnose plasma cell dyscrasia failed to detect λ+ monoclonal PCs. Twenty-four (83%) of the 29 LC clonal sequences found were derived from the IGLV1-40 and IGLV1-44 germline genes, as well as 2 from the closely related IGLV1-36 gene, and all were associated with an IGLJ3*02 junction (J) gene, confirming the high restriction of VJ region usage in POEMS syndrome. RACE-RepSeq VJ full-length sequencing additionally revealed original mutational patterns, the strong specificity of which might crucially help establish or eliminate the diagnosis of POEMS syndrome in uncertain cases. Thus, RACE-RepSeq appears as a sensitive, rapid, and specific tool to detect low-abundance PC clones in BM and assign them to POEMS syndrome, with all the consequences for therapeutic options.

HLA-DRB3/4/5 mismatches are associated with increased risk of acute GVHD in 10/10 matched unrelated donor hematopoietic cell transplantation.

Matching for HLA-A, -B, -C, and -DRB1 loci (8/8 match) is currently the gold standard for unrelated donor hematopoietic cell transplantation (HCT). In Europe, patients are also matched at the HLA-DQB1 loci (10/10 match). However, there is increasing evidence that matching at HLA-DRB3/4/5 loci may help to lower transplant-related morbidity and mortality. We therefore investigated the impact of HLA-DRB3/4/5 mismatches on outcomes in 1975 patients who received a first 10/10 matched unrelated donor (MUD) HCT in France from 2000 to 2012 for a hematological malignancy. High-resolution typing was performed at HLA-A, -B, -C, -DRB1, -DQB1, -DPB1, and -DRB3/4/5 loci for all donor/recipient pairs. Compared with DRB3/4/5-matched pairs, patients who received a MUD HCT from a DRB3/4/5 mismatched donor had a significantly increased risk of grade II-IV acute graft-versus-host disease (aGVHD) (Adjusted Hazard Ratio (HR) 1.43 (1.07 to 1.90)) associated with lower graft-versus-host disease-free and relapse-free survival (GRFS) (Adjusted HR 1.20 (1.02 to 1.42)). Conversely, we observed no differences in terms of chronic GVHD, nonrelapse mortality, relapse and overall survival. However, we believe that patients stand to benefit from DRB3/4/5 loci being considered for unrelated donor selection to improve GRFS and then quality of life after unrelated HCT.

Uterus human leucocyte antigen expression in the perspective of transplantation.

AIM: To describe class I and II human leucocyte antigen (HLA) expression using different uterine tissues in the perspective of uterus transplantation. METHODS: Human uterine tissues were obtained from 12 women who had undergone hysterectomy for the treatment of benign disease. HLA class I and HLA-antigen D related (DR) expression were assessed via immunochemistry. HLA class I expression in the uterus was compared with expression in other organs and tissues, including kidney and myocardium samples. RESULTS: HLA class I expression was strong in the endometrial glands and mild in the myometrium. Staining of endometrial glands was similar to glomerular staining in the kidney. The myometrium seems to express HLA class I similarly to hepatocytes and myocardial cells. HLA class I expression in the uterus did not differ in younger or post-menopausal women. HLA-DR was expressed in the endometrial glands, but not in the myometrium. A lack of HLA-DR expression seemed to be correlated with cell proliferation. CONCLUSION: HLA expression in the endometrium and myometrium is different. The endometrium should be the major target of alloreactive response. As for other transplanted organs, assessment of HLA unacceptable antigens and multiple immunosuppressive treatments is necessary in uterus transplantation.

Immune-Mediated Diseases Following COVID-19 Vaccination: Report of a Teaching Hospital-Based Case-Series.

The occurrence and course of immune-mediated diseases (IMDs) following COVID-19 vaccination has been little explored so far. We retrieved, among adult patients hospitalized at the Internal Department of a French university hospital up to May 2022, all those who had developed, or relapsed to, an IMD less than 3 weeks following COVID-19 vaccination, without other triggers. Twenty-seven (24 new-onset) post-COVID-19 vaccine IMDs were recorded. They comprised giant cell arteritis or polymyalgia rheumatica (n = 16, HLA-DRB1*04 in 58% of 12 assessed GCA cases), immune-mediated necrotizing myositis or acute rhabdomyolysis, systemic vasculitis, immune thrombocytopenic purpura, rheumatoid arthritis, anti-synthetase syndrome, and adult-onset Still's disease. The causative vaccines were mRNA-based (20 cases) or viral vector-based (7 cases). The IMD typically occurred after the first vaccine dose, with an average delay of 8 (5 SD) days. The patients' mean age was 67 years, and 58% were women. The IMDs had protracted courses in all but three of the patients and typically required high-dose glucocorticoids, in combination with immunomodulators in 13 patients. One patient died of intractable rhabdomyolysis, whereas five suffered permanent damage from IMDs. Eleven patients with well-controlled IMDs completed their COVID-19 vaccination schedule, and two suffered mild IMD relapses. There is a risk of IMDs, notably GCA/PMR, and muscle disorders, following COVID-19 vaccination. Such adverse reactions typically occurred after the first dose, raising concern about subsequent COVID-19 vaccinations. However, early re-challenge in well-controlled IMDs appeared safe.

Giant cell arteritis or polymyalgia rheumatica after influenza vaccination: A study of 12 patients and a literature review.

INTRODUCTION: Giant cell arteritis (GCA) and polymyalgia rheumatica (PMR) are inflammatory rheumatic diseases common in people over the age of 50 years. Seasonal influenza vaccination (IV) is strongly recommended in this population, among whom it is considered to be effective and well tolerated. IV-induced GCA or PMR are thought to be exceptional. PATIENTS AND METHODS: We retrieved all post-IV cases from an inception cohort of patients with newly diagnosed GCA. We also included two patients with post-IV PMR and reviewed all published reports of post-IV GCA or PMR, with selection of cases demonstrating disease onset within 1 month following IV. We compared the results of HLA-DRB1 typing, performed in seven patients with post-IV GCA or PMR, with those of 11 GCA patients with familial aggregation and 16 randomly selected GCA patients without a reported trigger. RESULTS: Of 358 GCA recruited since 2002, 10 (2.8%) qualified for post-IV GCA, of whom two also showed familial aggregation. Thirty-two patients (19 with GCA and 13 with PMR) including our patients were reviewed; their mean age was 71.8 ± 7.4 years and the M/F ratio was 0.8. Six patients (19%) had a history of PMR. Patients with post-IV GCA/PMR had the DRB1*13:01 haplotype more frequently compared to those with familial GCA (5/7 vs. 2/11, p = 0.048) or with GCA without a known trigger (3/16, p = 0.026). Post-IV PMR generally appeared self-limited, whereas post-IV GCA often displayed a more protracted course (chronic relapsing disease in one-third of the patients). CONCLUSION: Post-IV onset of GCA/PMR is not an exceptional occurrence and may be part of the spectrum of the autoimmune syndrome induced by adjuvants (ASIA). IV can trigger GCA or PMR, especially in persons at higher spontaneous risk, such as those with a personal or familial history of GCA/PMR. Whether the presence of the DRB1*13:01 allele further increases the risk of post-IV GCA/PMR through a stronger vaccine-induced immune reaction deserves further investigation. Unlike PMR, GCA can be a serious complication of IV.

A Prognostic Tool for Individualized Prediction of Graft Failure Risk within Ten Years after Kidney Transplantation.

Identification of patients at risk of kidney graft loss relies on early individual prediction of graft failure. Data from 616 kidney transplant recipients with a follow-up of at least one year were retrospectively studied. A joint latent class model investigating the impact of serum creatinine (Scr) time-trajectories and onset of de novo donor-specific anti-HLA antibody (dnDSA) on graft survival was developed. The capacity of the model to calculate individual predicted probabilities of graft failure over time was evaluated in 80 independent patients. The model classified the patients in three latent classes with significantly different Scr time profiles and different graft survivals. Donor age contributed to explaining latent class membership. In addition to the SCr classes, the other variables retained in the survival model were proteinuria measured one-year after transplantation (HR=2.4, p=0.01), pretransplant non-donor-specific antibodies (HR=3.3, p<0.001), and dnDSA in patient who experienced acute rejection (HR=15.9, p=0.02). In the validation dataset, individual predictions of graft failure risk provided good predictive performances (sensitivity, specificity, and overall accuracy of graft failure prediction at ten years were 77.7%, 95.8%, and 85%, resp.) for the 60 patients who had not developed dnDSA. For patients with dnDSA individual risk of graft failure was not predicted with a so good performance.

Improvement in HLA-typing by new sequence-specific oligonucleotides kits for HLA-A, -B, and -DRB1 loci.

Polymerase chain reaction sequence-specific oligonucleotide is commonly used for HLA-typing. We replaced our LabType SSO HD (HD) kits with LabType SSO XR (XR) kits (One Lambda, Inc., Canoga Park, California) for HLA-A, -B, and -DRB1 following acquisition of a LABScan3D analyzer. The XR kits have more bead regions than the HD kits, allowing for an extended number of probes and exon coverage. They are claimed to improve typing resolution and to diminish the number of allele ambiguities, including common and well-documented (CWD) and null alleles to be resolved. We retrospectively selected patients who had their first HLA-typing performed with the HD kits and their second determination with the XR kits between 2015 and 2016. Forty-two patients were selected for HLA-A typing comparison, and 48 for HLA-B and 41 for HLA-DRB1. XR kits significantly decreased the number of allele ambiguities for HLA-A and -B. On the other hand, the improvement was limited for the HLA-DRB1 locus. The XR kits did not resolve all the CWD HLA allele ambiguities, which may be important for organ and/or hematopoietic stem cell transplantations. The XR kits eliminated 88%, 62%, and 27% of null allele ambiguities for HLA-A, -B, and -DRB1 loci, respectively. In conclusion, the XR kits allow for a significant improvement of HLA-typing resolution for HLA-A and -B loci in comparison with HD kits. In contrast, the number of oligonucleotides in the XR HLA-DRB1 kit should be extended to include exon 3 at the very least. It could also be interesting to include oligonucleotides allowing HLA-DRB3, 4, and 5 typing.

An adjustable predictive score of graft survival in kidney transplant patients and the levels of risk linked to de novo donor-specific anti-HLA antibodies.

Most predictive models and scores of graft survival in renal transplantation include factors known before transplant or at the end of the first year. They cannot be updated thereafter, even in patients developing donor-specific anti-HLA antibodies and acute rejection.We developed a conditional and adjustable score for prediction of graft failure (AdGFS) up to 10 years post-transplantation in 664 kidney transplant patients. AdGFS was externally validated and calibrated in 896 kidney transplant patients.The final model included five baseline factors (pretransplant non donor-specific anti-HLA antibodies, donor age, serum creatinine measured at 1 year, longitudinal serum creatinine clusters during the first year, proteinuria measured at 1 year), and two predictors updated over time (de novo donor-specific anti-HLA antibodies and first acute rejection). AdGFS was able to stratify patients into four risk-groups, at different post-transplantation times. It showed good discrimination (time-dependent ROC curve at ten years: 0.83 (CI95% 0.76-0.89).