A specific diagnostic metabolome signature in adult IgA vasculitis.

INTRODUCTION: IgA vasculitis diagnosis relies primarily on clinical features and is confirmed by pathological findings. To date, there is no reliable noninvasive diagnostic biomarker. OBJECTIVE: We aimed to explore the baseline serum metabolome of adult patients with IgA vasculitis to identify potential diagnostic biomarkers. METHODS: We performed a study comparing the serum metabolome of patients with IgA vasculitis to that of patients with inflammatory condition, namely spondyloarthritis. Serum analyses were performed by high-performance liquid chromatography-mass spectrometry. RESULTS: Fifty-five patients with IgA vasculitis and 77 controls with spondyloarthritis (age- and sex-matched) were included in this study. The median age of IgA vasculitis patients was 53 years. Two-thirds of patients were female (n = 32). At the time of vasculitis diagnosis, 100% of patients had skin involvement and 69% presented with glomerulonephritis (n = 38). Joint and digestive involvement were observed in 56% (n = 31) and 42% (n = 23) of patients. Four discriminative metabolites between the two groups were identified: 1-methyladenosine, L-glutamic acid, serotonin, and thymidine. The multivariate model built from the serum metabolomes of patients with IgA vasculitis and spondyloarthritis revealed an accuracy > 90%. As this model was significant according to the permutation test (p < 0.01), independent validation showed an excellent predictive value of the test set: sensitivity 98%; specificity 98%, positive predictive value 97% and negative predictive value 98%. CONCLUSION: To our knowledge, this study is the first to use the metabolomic approach for diagnostic purposes in adult IgA vasculitis, highlighting a specific diagnostic metabolome signature.

Impact of gender on baseline presentation and outcome in adult IgA vasculitis.

OBJECTIVES: Adult IgA vasculitis (IgAV) is more common in males, but the potential impact of gender remains unclear. We aimed to describe the impact of gender on presentation and outcome in adult IgAV. METHODS: We retrospectively analysed data from a multicentre retrospective cohort of 260 patients (IGAVAS). Comparisons were made according to gender status. RESULTS: Data from 259 patients (95 females and 164 males) were analysed. Compared with females, baseline presentation in males was similar for cutaneous involvement (100% vs 100%, p= 1.0), joint involvement (60% vs 63%, p= 0.7), gastrointestinal involvement (57% vs 45%, p= 0.093) and glomerulonephritis (73% vs 64%, p= 0.16). Glomerulonephritis was more severe at baseline in males than in females, with a lower median estimated glomerular filtration rate (eGFR) (90 [IQR 59-105] vs 97 ml/min/1.73m2 [76-116], p= 0.015) and increased median proteinuria (0.84 vs 0.58 g/day, p= 0.01). There were no differences in histological findings in patients who had a kidney biopsy. Methylprednisolone was more frequently used in males (40% vs22%, p= 0.015), as were immunosuppressants, especially cyclophosphamide 24% vs 6%, p= 0.0025) and azathioprine (10% vs 2%, p= 0.038). Analysis of treatment response showed that males had more frequent refractory disease (30% vs 13%, p= 0.004). Long-term outcomes (mortality and progression to chronic kidney failure) did not differ. CONCLUSION: Kidney involvement in IgAV appears to more severe in males, which is supported by more intensive treatment contrasting with a lower response rate. This study raises the question of gender as a new prognostic factor in adult IgAV.

New insights into epidemiological data and impact of the COVID-19 pandemic on IgA vasculitis in children and adults: a French nationwide cohort.

IgA vasculitis (IgAV) is a small size vasculitis for which epidemiologic data are strikingly lacking, especially about the adult form. Additionally, the COVID-19 pandemic seems to have profoundly modified the incidence of this disease. Here, we aimed to establish some relevant epidemiological data in both pediatric and adult IgAV. We performed an observational study using a national database called "BNDMR" on IgAV, which gathers patients managed in the French network of experts on rare diseases. We primarily performed descriptive statistics over the 2010-2022 period. Then, we compared the North-South geographical areas, the seasonality, and the impact of COVID-19 with that of other patients reported in the same centers. We collected data from 1988 IgAV patients. The sex ratio was 1.57 for adults and 1.05 for children. The annual incidence in 2021 was 0.06 for 100,000 adults and 0.50 for 100,000 children. Compared with other diseases reported into the BNDMR, IgAV was more common in the South than in the North of France (OR 4.88 [4.17-5.74] in adults and OR 1.51 [1.35-1.68] in children). IgAV was also observed more frequently in winter and autumn. Strikingly, we observed a decrease in incidence during the COVID-19 pandemic period in children (OR 0.62 [0.47-0.81]). Our study provides both new insights and confirmations of IgAV epidemiological data: winter and autumn seasonality, more pronounced male predominance in adults, decreasing incidence of pediatric IgAV during the COVID-19 pandemic and increasing incidence in the South of France.

The diagnostic challenge of patients with anti-U1-RNP antibodies.

Anti-U1-RNP antibodies are necessary for the diagnosis of mixed connective tissue disease (MCTD), but they are also prevalent in other connective tissue diseases, especially systemic lupus erythematosus (SLE), from which distinction remains challenging. We aimed to describe the presentation and outcome of patients with anti-U1-RNP antibodies and to identify factors to distinguish MCTD from SLE. We retrospectively applied the criteria sets for MCTD, SLE, systemic sclerosis (SSc) and rheumatoid arthritis (RA) to all patients displaying anti-U1-RNP antibodies in the hospital of Caen from 2000 to 2020. Thirty-six patients were included in the analysis. Eighteen patients (50%) satisfied at least one of the MCTD classifications, 11 of whom (61%) also met 2019 ACR/EULAR criteria for SLE. Twelve other patients only met SLE without MCTD criteria, and a total of 23 patients (64%) met SLE criteria. The most frequent manifestations included Raynaud's phenomenon (RP, 91%) and arthralgia (67%). We compared the characteristics of patients meeting only the MCTD (n = 7), SLE (n = 12), or both (n = 11) criteria. Patients meeting the MCTD criteria were more likely to display SSc features, including sclerodactyly (p < 0.01), swollen hands (p < 0.01), RP (p = 0.04) and esophageal reflux (p < 0.01). The presence of scleroderma features (swollen hands, sclerodactyly, gastro-oesophageal reflux), was significantly associated with the diagnosis of MCTD. Conversely, the absence of those manifestations suggested the diagnosis of another definite connective tissue disease, especially SLE.

Efficacy and safety of TNF-α antagonists and tocilizumab in Takayasu arteritis: multicentre retrospective study of 209 patients.

OBJECTIVE: To assess the safety and the efficacy of TNF-α antagonists and tocilizumab in patients with Takayasu arteritis (TAK). METHODS: A total of 209 patients with TAK [median age 29 years (interquartile range 7-62)], 186 (89%) females] were included. They received either TNF-α antagonists [n = 132 (63%) with 172 lines; infliximab (n = 109), adalimumab (n = 45), golimumab (n = 8), certolizumab (n = 6) and etanercept (n = 5)] or tocilizumab [n = 77 (37%) with 121 lines; i.v. and s.c. in 95 and 26 cases, respectively]. RESULTS: A complete response at 6 months was evidenced in 101/152 (66%) patients on TNF-α antagonists and 75/107 (70%) patients on tocilizumab. Age ≥30 years [odds ratio 2.09 (95% CI 1.09, 3.99)] was associated with complete response, whereas vascular signs [OR 0.26 (95% CI 0.1, 0.65)], baseline prednisone ≥20 mg/day [OR 0.51 (95% CI 0.28, 0.93)] were negatively associated with the complete response to TNF-α antagonists or tocilizumab. During a median follow-up of 36 months, 103 relapses were noted. Supra-aortic branches and thoracic aorta involvement [HR 2.44 (95% CI 1.06, 5.65) and 3.66 (1.18, 11.4), respectively] and systemic signs at baseline [HR 2.01 (95% CI 1.30, 3.11)] were significantly associated with relapse. The cumulative incidence of treatment discontinuation and relapse were similar in TNF-α antagonists and tocilizumab. Fifty-eight (20%) adverse effects occurred on biologic targeted therapies [37 (21%) on TNF-α antagonists and 21 (17%) on tocilizumab (P = 0.4), respectively]. CONCLUSION: This large multicentre study shows high efficacy of biologic targeted treatments in refractory TAK. Efficacy, relapse and drug retention rate were equivalent with TNF-α antagonists and tocilizumab.

Impact of aging on phenotype and prognosis in IgA vasculitis.

OBJECTIVES: Immunoglobulin A vasculitis (IgAV) is a small-vessel vasculitis most frequently benign in children while more severe in adults. We aimed to study the impact of age on presentation and outcome of adult IgAV. METHODS: We conducted a nationwide retrospective study including 260 IgAV patients. Patients were divided into four quartiles according to the age at IgAV diagnosis: <36, 36 ≤ age < 52; 52 ≤ age < 63 and ≥63 years. Comparison of presentation and outcome were performed according to age of disease onset. RESULTS: Mean age at diagnosis was 50.1 (18) years and 63% were male. IgAV diagnosed in the lowest quartile of age was associated with more frequent joint (P < 0.0001) and gastrointestinal involvement (P = 0.001). In contrast, the oldest patients had more severe purpura with necrotic lesions (P = 0.001) and more frequent renal involvement (P < 0.0001), with more frequent haematuria, renal failure, higher urine protein excretion and more frequent tubulointerstitial lesions. Patients were treated similarly in all groups of age, and clinical response and relapse rates were similar between groups. In the 127 treated patients with follow-up data for >6 months, clinical response and relapse rates were similar between the four groups. Median follow-up was of 17.2 months (9.1-38.3 months). Renal failure at the end of follow-up was significantly more frequent in the highest quartile of age (P = 0.02), but the occurrence of end-stage renal disease was similar in all groups. Last, overall and IgAV-related deaths were associated with increase in age. CONCLUSION: Aging negatively impacts the severity and outcome of IgAV in adults. Younger patients have more frequent joint and gastrointestinal involvement, while old patients display more frequent severe purpura and glomerulonephritis.

Gastrointestinal involvement in adult IgA vasculitis (Henoch-Schönlein purpura): updated picture from a French multicentre and retrospective series of 260 cases.

OBJECTIVES: To describe the clinical presentation, treatments and prognosis of gastrointestinal (GI) involvement in adult IgA vasculitis (IgAV). METHODS: Data from 260 adults with IgAV included in a French multicentre retrospective survey were analysed. Presentation and outcomes of patients with (GI+) and without (GI-) GI involvement were compared. RESULTS: One hundred and thirty-seven (53%) patients had GI involvement. Initial manifestations were abdominal pain in 99%, intestinal bleeding in 31%, diarrhoea in 26% and acute surgical abdomen in only 4%. Abdominal imaging revealed thickening of intestinal wall in 61%, and endoscopies revealed abnormalities in 87%, mostly mucosal ulcerations. GI+ vs GI- patients were younger (46 ± 18 vs 54 ± 18 years; P = 0.0004), had more constitutional symptoms (43% vs 23%; P = 0.0005) and joint involvement (72 vs 50%; P = 0.0002), and higher CRP levels (3.7 vs 1.9 mg/dl; P = 0.001). Clinical response and relapse rates were comparable between groups, and all causes mortality (2 vs 4%) and IgAV-related mortality (1% vs 2%) as well. GI-related deaths were due to intestinal perforation and mesenteric ischaemia. CONCLUSION: GI involvement is frequent in adult IgAV. GI involvement is frequent in adult IgAV. Mortality is not uncommon but does not seem to be specifically related to GI. Immunosuppressants should not be preferred as first-line therapy for GI+ patients but may be required in case of acute surgical abdomen.

Recruitment of CXCR3+ T cells into injured tissues in adult IgA vasculitis patients correlates with disease activity.

OBJECTIVES: Adult immunoglobulin A vasculitis (IgAV) is an immune complex small vessel vasculitis. So far, the involvement of T cells in this pathology has been poorly studied. The aim of this study was to analyze T-cell homeostasis as well as cytokine and chemokine concentrations in the blood and tissues of IgAV patients. METHODS: T cells, cytokine and chemokine concentrations were analyzed in peripheral blood using flow cytometry and multiplex assays. T-cell infiltrates in the kidney and the skin were characterized by immunohistochemistry. This study prospectively included 44 adult patients with biopsy-proven IgAV and 24 age- and sex-matched healthy controls. RESULTS: We observed reduced proportions of circulating CXCR5-and CXCR3-expressing memory CD4 T cells at diagnosis but normal values at remission. The plasma levels of Th1-related cytokines (IL-12, IL-27 and IFNγ) and of the TFH-related cytokine, IL-21, were paradoxically not reduced in patients. We observed increased plasma concentrations of the CXCR5 ligand, CXCL13, and of the CXCR3 ligands, CXCL10/11, suggesting a potential relocation of the corresponding T cells into inflamed tissues. We then confirmed the recruitment of CXCR3-expressing T cells into the skin and kidneys. In the skin, T-cell infiltrates mainly co-localized with damaged dermal small vessels. Finally, patients with the largest kidney T-cell infiltrates were also those with the highest proteinuria. CONCLUSION: Altogether, our results strongly suggest that, in IgAV patients, CXCL10/11 orchestrate the recruitment of CXCR3-expressing T cells in injured tissues, contributing to tissue damage and disease activity.

Macrophages Induce Long-Term Trapping of γδ T Cells with Innate-like Properties within Secondary Lymphoid Organs in the Steady State.

So far, peripheral T cells have mostly been described to circulate between blood, secondary lymphoid organs (SLOs), and lymph in the steady state. This nomadic existence would allow them to accomplish their surveying task for both foreign Ags and survival signals. Although it is now well established that γδ T cells can be rapidly recruited to inflammatory sites or in certain tumor microenvironments, the trafficking properties of peripheral γδ T cells have been poorly studied in the steady state. In the present study, we highlight the existence of resident γδ T cells in the SLOs of specific pathogen-free mice. Indeed, using several experimental approaches such as the injection of integrin-neutralizing Abs that inhibit the entry of circulating lymphocytes into lymph nodes and long-term parabiosis experiments, we have found that, contrary to Ly-6C-/+CD44lo and Ly-6C+CD44hi γδ T cells, a significant proportion of Ly-6C-CD44hi γδ T cells are trapped for long periods of time within lymph nodes and the spleen in the steady state. Specific in vivo cell depletion strategies have allowed us to demonstrate that macrophages are the main actors involved in this long-term retention of Ly-6C-CD44hi γδ T cells in SLOs.

Iron boosts anti-tumor type 1 T-cell responses and anti-PD1 immunotherapy.

Cancers only develop if they escape immunosurveillance, and the success of cancer immunotherapies relies in most cases on their ability to restore effector T-cell functions, particularly IFN-γ production. Revolutionizing the treatment of many cancers, immunotherapies targeting immune checkpoints such as PD1 can increase survival and cure patients. Unfortunately, although immunotherapy has greatly improved the prognosis of patients, not all respond to anti-PD1 immunotherapy, making it crucial to identify alternative treatments that could be combined with current immunotherapies to improve their effectiveness. Here, we show that iron supplementation significantly boosts T-cell responses in vivo and in vitro. This boost is associated with a metabolic reprogramming of T cells in favor of lipid oxidation. We also found that the "adjuvant" effect of iron led to a marked slowdown of tumor-cell growth after tumor-cell line transplantation in mice. Specifically, our results suggest that iron supplementation promotes anti-tumor responses by increasing IFN-γ production by T cells. In addition, iron supplementation considerably improves the efficacy of anti-PD1 cancer immunotherapy in mice. Finally, our study suggests that, in cancer patients, the quality and efficacy of the anti-tumor response following anti-PD1 immunotherapy may be modulated by plasma ferritin levels. In summary, our results suggest the benefits of iron supplementation on the reactivation of anti-tumor responses and support the relevance of a fruitful association between immunotherapy and iron supplementation.

[Adult IgA vasculitis]. / Vascularite à IgA de l'adulte.

ADULT IGA VASCULITIS. IgA vasculitis previously named rheumatoid purpura is a rare systemic vasculitis in adults involving small vessels and associated with the presence of immunoglobulin A deposits. IgA vasculitis is often triggerd by infections, taking medication and vaccination. It is characterised by the presence of vascular purpura associated with joint (arthralgia), gastrointestinal (abdominal pain) and sometimes renal involvement (glomerulonephritis). Gastrointestinal involvement can be lifethreatening (bowel perforation), while the longterm prognosis is shaped by the renal involvement (renal failure). In most cases, the disease has a good outcome and only symptomatic treatment is recommended. In more severe forms, corticosteroids, combined with another immunosuppressant or biotherapy, may be discussed on a casebycase basis.

VASCULARITE À IGA DE L'ADULTE. La vascularite à IgA, anciennement appelée purpura rhumatoïde, est une vascularite systémique liée à la présence de dépôts d'immunoglobulines A dans les vaisseaux de petit calibre. Elle fait souvent suite à un facteur déclenchant, comme une infection du tractus respiratoire, la prise d'un médicament ou une vaccination. Elle est caractérisée par la présence d'un purpura vasculaire associé à une atteinte articulaire (arthralgies typiquement des chevilles), gastrointestinale (douleurs abdominales) et parfois rénale (glomérulonéphrite). Le pronostic vital peut être engagé par l'atteinte gastrointestinale (risque de perforation digestive), alors que le pronostic à long terme est lié à l'atteinte rénale (risque d'insuffisance rénale chronique). La maladie évolue généralement favorablement, et seul un traitement symptomatique est conseillé. Dans les formes plus sévères, des corticostéroïdes, associés à un immunosuppresseur ou une biothérapie, peuvent être discutés au cas par cas.

COVID-19 Vaccination as a Trigger of IgA Vasculitis: A Global Pharmacovigilance Study.

OBJECTIVE: IgA vasculitis (IgAV) can occur after vaccination. We aimed to assess a potential safety signal on the association between coronavirus disease 2019 (COVID-19) vaccines and IgAV. METHODS: Cases of IgAV involving COVID-19 vaccines were retrieved in VigiBase. Disproportionate reporting was assessed using the Bayesian information component (IC) with all other drugs and vaccines as control groups. RESULTS: Three hundred thirty patients with de novo IgAV from 24 countries were included, mostly from the United States (193/330, 58%). Fifty percent (163/328) were female and median age was 32 years (IQR 15-59), of which 33% (84/254) were young (1-17 yrs). Median time to onset of IgAV was 7 days (IQR 2-16; n = 256) and 85% (280/330) of patients were vaccinated with mRNA vaccines. Seriousness was reported in 188/324 (58%) cases. Sixty-five percent (95/147) recovered and 1% (2/147) died. A positive rechallenge was reported for 3 of 4 patients (75%). A total of 996 cases of IgAV were identified with other vaccines. There was a small significant increase in IgAV reporting with COVID-19 vaccines compared with all other drugs (IC 0.22, 95% credible interval [CrI] 0.04 to 0.35). No disproportionality signal was found between COVID-19 vaccines and other vaccines (IC -1.42, 95% CrI -1.60 to -1.28). There was no significant difference between mRNA vaccines and viral vector COVID-19 vaccines. Men and children had a significant overreporting of IgAV compared with women and adults, respectively. CONCLUSION: This study provides reassuring results regarding the safety of COVID-19 vaccines in the occurrence of IgAV compared to other vaccines.

Joint manifestations revealing inborn metabolic diseases in adults: a narrative review.

Inborn metabolic diseases (IMD) are rare conditions that can be diagnosed during adulthood. Patients with IMD may have joint symptoms and the challenge is to establish an early diagnosis in order to institute appropriate treatment and prevent irreversible damage. This review describes the joint manifestations of IMD that may be encountered in adults. The clinical settings considered were arthralgia and joint stiffness as well as arthritis. Unspecific arthralgias are often the first symptoms of hereditary hemochromatosis, chronic low back pain may reveal an intervertebral disc calcification in relation with alkaptonuria, and progressive joint stiffness may correspond to a mucopolysaccharidosis or mucolipidosis. Gaucher disease is initially revealed by painful acute attacks mimicking joint pain described as "bone crises". Some IMD may induce microcrystalline arthropathy. Beyond classical gout, there are also gouts in connection with purine metabolism disorders known as "enzymopathic gouts". Pyrophosphate arthropathy can also be part of the clinical spectrum of Gitelman syndrome or hypophosphatasia. Oxalate crystals arthritis can reveal a primary hyperoxaluria. Destructive arthritis may be indicative of Wilson's disease. Non-destructive arthritis may be seen in mevalonate kinase deficiency and familial hypercholesterolemia.

Adverse effect of Pneumocystis Jirovecii infection associated with rituximab therapy for autoimmune disease are more frequently reported in older vs. younger patient.

INTRODUCTION: Rituximab is a chimeric anti-CD20 antibody commonly used to treat patients with autoimmune diseases. Such diseases mainly affect young people, but older patients may also be concerned. So far, very little data exist concerning the safety of rituximab in older patients with autoimmune diseases. METHODS: This study was intended to describe the adverse reaction profile of rituximab in patients over 75 years of age treated for autoimmune diseases and to compare such profile to those observed in patients below 75 years of age. Adverse reactions related to rituximab were reported to the French Pharmacovigilance Network. From such reports, a descriptive analysis as well as a disproportionality analysis were performed to identify safety signals. RESULTS: 1096 reports of rituximab-related adverse reactions reported in France between 2006 and 2019, were included in the study, such as 127 in the older group (>75 years) and 969 in the younger group (<75 years). Infusion reactions were less frequently reported than other adverse drug reaction in older patients (11 vs. 27%, P<0.001). By contrast, a higher rate of opportunistic infection due to Pneumocystis jirovecii was reported in the older subject group (3.9 vs. 0.6%, P<0.001), along with neutropenia (22.8 vs. 9.3%, P<0.0001). These results were confirmed by the disproportionality analysis. CONCLUSION: Pneumocystis jirovecii infection was significatively more reported in older patients treated by Rituximab which probably reflects a higher incidence in this population. The use of anti-pneumocystis prophylaxis should be considered in this population.

Towards better indications for kidney biopsy in adult IgA vasculitis: a clinical-laboratory and pathology correlation study.

BACKGROUND: Indications for kidney biopsy in adult IgA vasculitis (IgAV) remain debated and there are very few studies on this subject. The aim of this study was to establish a correlation between renal histological and clinical-laboratory data. METHODS: A retrospective multicenter study was conducted using three databases from French hospitals, gathered between 1977 and 2020. The study included 294 adult patients with IgAV who had undergone kidney biopsy assessed according to the prognostic "Pillebout classification". Different statistical models were used to test the correlations between histological and clinical-laboratory data: Cochran Armitage, ANOVA, Kruskal-Wallis and logistic regression. RESULTS: The patients were primarily men (64%), with a mean age of 52 years. The main organs and tissues involved were: dermatological 100%, digestive 48% and rheumatological 61%. All had features of kidney involvement. The median serum creatinine was 96 µmol/L serum albumin 35 g/L, and C-reactive protein 28 mg/L. Of the patients, 86% (n = 254) had hematuria and median proteinuria was 1.8 g/day. The only statistically significant correlation between the pathological stages and the clinical-laboratory data was the presence of hematuria (p = 0.03, 66% class I to 92% class IV). In multivariate analysis, only albuminemia was associated with extracapillary proliferation (p = 0.02; OR 0.94) and only age was associated with stages 3-4 (p = 0.03; OR 1.02). CONCLUSION: Our study suggests that there is no strict baseline correlation between renal pathology and clinical-laboratory data. Given the current knowledge, it seems relevant to recommend a kidney biopsy in the presence of significant and persistent proteinuria or unexplained kidney function decline.

No evidence for systemic low-grade inflammation in adult patients with early-treated phenylketonuria: The INGRAPH study.

The question of an increased cardiovascular risk has been recently raised in adults with phenylketonuria (PKU). As low-grade systemic inflammation increases cardiovascular risk, the INGRAPH study aimed to evaluate low-grade inflammation in adult PKU patients compared to healthy controls and to determine the potential influence of Phe-controlled diet on inflammation. Twenty early-treated adult PKU patients, including a subgroup of 15 classical PKU patients, and 20 healthy volunteers were included. PKU patients and healthy subjects were matched on age, sex and body mass index class. Plasma concentrations of CRP, IFNg, IL1a, IL1b, IL2, IL6, IL10, and TNFα were measured in PKU patients and compared to controls. Plasma CRP was not different in the PKU group as compared to controls. No significant differences were observed between the two groups concerning plasma cytokines concentrations. Plasma CRP and cytokine profile were not different between "on diet" and "off diet" PKU patients. All these results were similar considering only the classical PKU subgroup. No differences were shown in plasma CRP and pro-inflammatory cytokines between adult PKU patients and healthy controls. Further studies are needed, including more patients and extensive characterization of systemic low-grade inflammation, as cardiovascular risk appears to be a new concern in adult PKU population.