Broadening the clinical spectrum of giant cell arteritis: from the classic cranial to the predominantly extracranial pattern of the disease.

INTRODUCTION: Giant cell arteritis (GCA) is a large vessel (LV) vasculitis that affects people aged 50 years and older. Classically, GCA was considered a disease that involved branches of the carotid artery. However, the advent of new imaging techniques has allowed us to reconsider the clinical spectrum of this vasculitis. AREASCOVERED: This review describes clinical differences between patients with the cranial GCA and those with a predominantly extracranial LV-GCA disease pattern. It highlights differences in the frequency of positive temporal artery biopsy depending on the predominant disease pattern and emphasizes the relevance of imaging techniques to identify patients with LV-GCA without cranial ischemic manifestations. The review shows that so far there are no well-established differences in genetic predisposition to GCA regardless of the predominant phenotype. EXPERT COMMENTARY: The large branches of the extracranial arteries are frequently affected in GCA. Imaging techniques are useful to identify the presence of 'silent' GCA in people presenting with polymyalgia rheumatica or with nonspecific manifestations. Whether these two different clinical presentations of GCA constitute a continuum in the clinical spectrum of the disease or whether they may be related but are definitely different conditions needs to be further investigated.

Risk loci involved in giant cell arteritis susceptibility: a genome-wide association study.

BACKGROUND: Giant cell arteritis is an age-related vasculitis that mainly affects the aorta and its branches in individuals aged 50 years and older. Current options for diagnosis and treatment are scarce, highlighting the need to better understand its underlying pathogenesis. Genome-wide association studies (GWAS) have emerged as a powerful tool for unravelling the pathogenic mechanisms involved in complex diseases. We aimed to characterise the genetic basis of giant cell arteritis by performing the largest GWAS of this vasculitis to date and to assess the functional consequences and clinical implications of identified risk loci. METHODS: We collected and meta-analysed genomic data from patients with giant cell arteritis and healthy controls of European ancestry from ten cohorts across Europe and North America. Eligible patients required confirmation of giant cell arteritis diagnosis by positive temporal artery biopsy, positive temporal artery doppler ultrasonography, or imaging techniques confirming large-vessel vasculitis. We assessed the functional consequences of loci associated with giant cell arteritis using cell enrichment analysis, fine-mapping, and causal gene prioritisation. We also performed a drug repurposing analysis and developed a polygenic risk score to explore the clinical implications of our findings. FINDINGS: We included a total of 3498 patients with giant cell arteritis and 15 550 controls. We identified three novel loci associated with risk of giant cell arteritis. Two loci, MFGE8 (rs8029053; p=4·96 × 10-8; OR 1·19 [95% CI 1·12-1·26]) and VTN (rs704; p=2·75 × 10-9; OR 0·84 [0·79-0·89]), were related to angiogenesis pathways and the third locus, CCDC25 (rs11782624; p=1·28 × 10-8; OR 1·18 [1·12-1·25]), was related to neutrophil extracellular traps (NETs). We also found an association between this vasculitis and HLA region and PLG. Variants associated with giant cell arteritis seemed to fulfil a specific regulatory role in crucial immune cell types. Furthermore, we identified several drugs that could represent promising candidates for treatment of this disease. The polygenic risk score model was able to identify individuals at increased risk of developing giant cell arteritis (90th percentile OR 2·87 [95% CI 2·15-3·82]; p=1·73 × 10-13). INTERPRETATION: We have found several additional loci associated with giant cell arteritis, highlighting the crucial role of angiogenesis in disease susceptibility. Our study represents a step forward in the translation of genomic findings to clinical practice in giant cell arteritis, proposing new treatments and a method to measure genetic predisposition to this vasculitis. FUNDING: Institute of Health Carlos III, Spanish Ministry of Science and Innovation, UK Medical Research Council, and National Institute for Health and Care Research.

Use of risk chart algorithms for the identification of psoriatic arthritis patients at high risk for cardiovascular disease: findings derived from the project CARMA cohort after a 7.5-year follow-up period.

OBJECTIVE: To assess the predictive value of four cardiovascular (CV) risk algorithms for identifying high-risk psoriatic arthritis (PsA) patients. METHODS: Evaluation of patients with PsA enrolled in the Spanish prospective project CARdiovascular in RheuMAtology. Baseline data of 669 PsA patients with no history of CV events at the baseline visit, who were followed in rheumatology outpatient clinics at tertiary centres for 7.5 years, were retrospectively analysed to test the performance of the Systematic Coronary Risk Assessment (SCORE), the modified version (mSCORE) European Alliance of Rheumatology Associations (EULAR) 2015/2016, the SCORE2 algorithm (the updated and improved version of SCORE) and the QRESEARCH risk estimator version 3 (QRISK3). RESULTS: Over 4790 years of follow-up, there were 34 CV events, resulting in a linearised rate of 7.10 per 1000 person-years (95% CI 4.92 to 9.92). The four CV risk scales showed strong correlations and all showed significant associations with CV events (p<0.001). SCORE, mSCORE EULAR 2015/2016 and QRISK3 effectively differentiated between low and high CV risk patients, although the cumulative rate of CV events observed over 7.5 years was lower than expected based on the frequency predicted by these risk scales. Additionally, model improvement was observed when combining QRISK3 with any other scale, particularly the combination of QRISK3 and SCORE2, which yielded the lowest Akaike information criterion (411.15) and Bayesian information criterion (420.10), making it the best predictive model. CONCLUSIONS: Risk chart algorithms are very useful for discriminating PsA at low and high CV risk. An integrated model featuring QRISK3 and SCORE2 yielded the optimal synergy of QRISK3's discrimination ability and SCORE2's calibration accuracy.

Incidence and clinical manifestations of giant cell arteritis in Spain: results of the ARTESER register.

OBJECTIVE: This study aimed to estimate the incidence of giant cell arteritis (GCA) in Spain and to analyse its clinical manifestations, and distribution by age group, sex, geographical area and season. METHODS: We included all patients diagnosed with GCA between 1 June 2013 and 29 March 2019 at 26 hospitals of the National Health System. They had to be aged ≥50 years and have at least one positive results in an objective diagnostic test (biopsy or imaging techniques), meet 3/5 of the 1990 American College of Rheumatology classification criteria or have a clinical diagnosis based on the expert opinion of the physician in charge. We calculated incidence rate using Poisson regression and assessed the influence of age, sex, geographical area and season. RESULTS: We identified 1675 cases of GCA with a mean age at diagnosis of 76.9±8.3 years. The annual incidence was estimated at 7.42 (95% CI 6.57 to 8.27) cases of GCA per 100 000 people ≥50 years with a peak for patients aged 80-84 years (23.06 (95% CI 20.89 to 25.4)). The incidence was greater in women (10.06 (95% CI 8.7 to 11.5)) than in men (4.83 (95% CI 3.8 to 5.9)). No significant differences were found between geographical distribution and incidence throughout the year (p=0.125). The phenotypes at diagnosis were cranial in 1091 patients, extracranial in 337 patients and mixed in 170 patients. CONCLUSIONS: This is the first study to estimate the incidence of GCA in Spain at a national level. We found a predominance among women and during the ninth decade of life with no clear variability according to geographical area or seasons of the year.

Management of Vertebral Fragility Fracture in Older People: Recommendations from a Spanish Consensus of Experts.

Vertebral fragility fractures (VFF) pose a challenge for appropriate care. The aim of this study was to develop consensus recommendations for the management of VFF in older people from a multidisciplinary approach. Specialists in osteoporosis belonging to different scientific societies reviewed the main clinical practice guidelines published in Spain in 2014. Thirty-five recommendations for the management of VFF were evaluated by seven experts using an anonymous survey. Consensus was defined as 80% of responses of 8 (agree) and 9 (strongly agree) on a Likert scale. Consensus was achieved in 22 recommendations (62.8%). The experts agreed on the need for anamnesis, clinical assessment, and laboratory tests, including erythrocyte sedimentation rate, proteinography, and the assessment of levels of calcium, vitamin D, alkaline phosphatase, and thyroid-stimulating hormone. Optional tests, such as bone turnover markers (BTMs), magnetic resonance imaging, bone scintigraphy, or using a fracture risk assessment tool (FRAX®), did not achieve an agreed consensus. Also, there was consensus regarding the administration of calcium/vitamin D supplements, the withdrawal of toxic habits, and personalized physical exercise. Participants agreed on the administration of teriparatide for 24 months and then a switch to denosumab or bisphosphonates in patients at high risk of fracture. Specialists in osteoporosis, primary care physicians, and geriatricians should be involved in the follow-up of patients with VFF. Although there was multidisciplinary agreement on diagnostic tests and non-pharmacological and pharmacological treatment in frail older people, therapeutic objectives should be individualized for every patient. In addition to the specific recommendations, close collaboration between the geriatrician and the primary care physician is essential for the optimal chronic management of frail patients with fragility fractures.

Combined use of QRISK3 and SCORE2 increases identification of ankylosing spondylitis patients at high cardiovascular risk: Results from the CARMA Project cohort after 7.5 years of follow-up.

OBJECTIVE: To establish the predictive value of the QRESEARCH risk estimator version 3 (QRISK3) algorithm in identifying Spanish patients with ankylosing spondylitis (AS) at high risk of cardiovascular (CV) events and CV mortality. We also sought to determine whether to combine QRISK3 with another CV risk algorithm: the traditional SCORE, the modified SCORE (mSCORE) EULAR 2015/2016 or the SCORE2 may increase the identification of AS patients with high-risk CV disease. METHODS: Information of 684 patients with AS from the Spanish prospective CARdiovascular in ReuMAtology (CARMA) project who at the time of the initial visit had no history of CV events and were followed in rheumatology outpatient clinics of tertiary centers for 7.5 years was reviewed. The risk chart algorithms were retrospectively tested using baseline data. RESULTS: After 4,907 years of follow-up, 33 AS patients had experienced CV events. Linearized rate=6.73 per 1000 person-years (95 % CI: 4.63, 9.44). The four CV risk scales were strongly correlated. QRISK3 correctly discriminated between people with lower and higher CV risk, although the percentage of accumulated events over 7.5 years was clearly lower than expected according to the risk established by QRISK3. Also, mSCORE EULAR 2015/2016 showed the same discrimination ability as SCORE, although the percentage of predicted events was clearly higher than the percentage of actual events. SCORE2 also had a strong discrimination capacity according to CV risk. Combining QRISK3 with any other scale improved the model. This was especially true for the combination of QRISK3 and SCORE2 which achieved the lowest AIC (406.70) and BIC (415.66), so this combination would be the best predictive model. CONCLUSIONS: In patients from the Spanish CARMA project, the four algorithms tested accurately discriminated those AS patients with higher CV risk and those with lower CV risk. Moreover, a model that includes QRISK3 and SCORE2 combined the best discrimination ability of QRISK3 with the best calibration of SCORE2.

Application of Nuclear Medicine Techniques in Musculoskeletal Infection: Current Trends and Future Prospects.

Nuclear medicine has become an indispensable discipline in the diagnosis and management of musculoskeletal infections. Radionuclide tests serve as a valuable diagnostic tool for patients suspected of having osteomyelitis, spondylodiscitis, or prosthetic joint infections. The choice of the most suitable imaging modality depends on various factors, including the affected area, potential extra osseous involvement, or the impact of previous bone/joint conditions. This review provides an update on the use of conventional radionuclide imaging tests and recent advancements in fusion imaging scans for the differential diagnosis of musculoskeletal infections. Furthermore, it examines the role of radionuclide scans in monitoring treatment responses and explores current trends in their application. We anticipate that this update will be of significant interest to internists, rheumatologists, radiologists, orthopedic surgeons, rehabilitation physicians, and other specialists involved in musculoskeletal pathology.

Visual manifestations in giant cell arteritis: identification of risk factors from the ARTESER Registry.

OBJECTIVE: To determine the prevalence and predictive factors of visual manifestations in a large registry of patients with GCA. METHODS: ARTESER is a large Spanish multicentre registry supported by the Spanish Society of Rheumatology. It includes patients with GCA from across the entire country diagnosed between June 2013 and March 2019. The variables collected at diagnosis were demographics, clinical manifestations (including all visual manifestations), laboratory, temporal artery biopsy, and imaging findings (ultrasound, FDG-PET/CT, MRI angiography, CT angiography). Patients with and without visual involvement were compared in a bivariate analysis. Multivariate logistic regression was performed to determine potential predictive factors of visual manifestations. RESULTS: The study population comprised 1636 GCA patients, of whom 599 (36.6%) presented visual manifestations. Anterior ischemic optic neuropathy was the most frequent (n = 274 of 599; 45.7%) ocular complication. The independent predictors that increased the risk (OR; 95% confidence interval) of visual involvement were older age (1.027; 1.009-1.045) and jaw claudication (1.724; 1.325-2.243). The variables associated with a reduced risk were polymyalgia rheumatica (0.541; 0.414-0.708), fever (0.373; 0.264-0.527), longer symptom duration (0.946; 0.909-0.985), and higher erythrocyte sedimentation rate (ESR) (0.992; 0.988-0.997), common features of patients with large vessel-GCA. CONCLUSION: One-third of GCA patients present visual manifestations at diagnosis. Older age and jaw claudication are independent predictors of visual manifestations, whereas polymyalgia rheumatica, fever, longer symptom duration, and high ESR reduce the risk of visual involvement.

Beneficial effect of temporary methotrexate interruption on B and T cell responses upon SARS-CoV-2 vaccination in patients with rheumatoid arthritis or psoriatic arthritis.

B and T cell responses were evaluated in patients with rheumatoid arthritis (RA) or psoriatic arthritis (PsA) after 1 or 2 weeks of methotrexate (MTX) withdrawal following each COVID-19 vaccine dose and compared with those who maintained MTX. Adult RA and PsA patients treated with MTX were recruited and randomly assigned to 3 groups: MTX-maintenance (n = 72), MTX-withdrawal for 1 week (n = 71) or MTX-withdrawal for 2 weeks (n = 73). Specific antibodies to several SARS-CoV-2 antigens and interferon (IFN)-γ and interleukin (IL)-21 responses were assessed. MTX withdrawal in patients without previous COVID-19 was associated with higher levels of anti-RBD IgG and neutralising antibodies, especially in the 2-week withdrawal group and with higher IFN-γ secretion upon stimulation with pools of SARS-CoV-2 S peptides. No increment of RA/PsA relapses was detected across groups. Our data indicate that two-week MTX interruption following COVID-19 vaccination in patients with RA or PsA improves humoral and cellular immune responses.

Abatacept in usual and in non-specific interstitial pneumonia associated with rheumatoid arthritis.

OBJECTIVE: To compare the effectiveness of abatacept (ABA) in Rheumatoid Arthritis-associated Interstitial Lung Disease (RA-ILD) according to the radiological patterns of usual (UIP) or non-specific interstitial pneumonia (NSIP). METHODS: From an observational longitudinal multicentre study of 263 RA-ILD patients treated with ABA, those with UIP or NSIP were selected. Lung function, chest high resolution computerised tomography (HRCT) and dyspnoea were recorded and compared in both groups from baseline to the end of follow-up (progression definitions: improvement or worsening >10% of FVC or DLCO, changes in HRCT extension and 1-point change in the mMRC scale, respectively). Differences between final and baseline visits were calculated as the average difference (95% CI) through mixed effects models regression. RESULTS: We studied 190 patients with UIP (n=106) and NSIP (n=84). General features were similar in both groups except for older age, positive rheumatoid factor, and previous sulfasalazine therapy, which were more frequent in patients with UIP. ILD duration up to ABA initiation was relatively short: median 16 [4-50] and 11 [2-36] months (p=0.36) in UIP and NSIP, respectively. Mean baseline FVC and DLCO were 82% and 63% in UIP and 89% and 65% in NSIP, respectively. Both parameters remained stable during 24 months with ABA. HRCT lesions and dyspnoea improved/stabilized in 73.1% and 90.5% and 72.9% and 94.6% of UIP and NSIP patterns, respectively. CONCLUSION: ABA seems equally effective in stabilizing dyspnoea, lung function and radiological impairment in both UIP and NSIP patterns of RA-ILD. Early administration of ABA may prevent RA-ILD progression, regardless of the radiological pattern.

COVID-19 Vaccination and Immunosuppressive Therapy in Immune-Mediated Inflammatory Diseases.

The COVID-19 vaccination program has probably been the most complex and extensive project in history until now, which has been a challenge for all the people involved in the planning and management of this program. Patients with immune-mediated inflammatory diseases (IMIDs) on immunosuppressive therapy have required special attention, not only because of the particular haste in carrying out the process but also because of the uncertainty regarding their response to the vaccines. We now have strong scientific evidence that supports the hypothesis that immunosuppressive therapy inhibits the humoral response to vaccines against other infectious agents, such as influenza, pneumococcus and hepatitis B. This has led to the hypothesis that the same could happen with the COVID-19 vaccine. Several studies have therefore already been carried out in this area, suggesting that temporarily discontinuing the administration of methotrexate for 2 weeks post-vaccination could improve the vaccine response, and other studies with various immunosuppressive drugs are in the same line. However, the fact of withholding or interrupting immunosuppressive therapy when dealing with COVID-19 vaccination remains unclear. On this basis, our article tries to compile the information available on the effect of immunosuppressant agents on COVID-19 vaccine responses in patients with IMIDs and proposes an algorithm for the management of these patients.

MICa/b-dependent activation of natural killer cells by CD64+ inflammatory type 2 dendritic cells contributes to autoimmunity.

Primary Sjögren's syndrome (pSS) is an inflammatory autoimmune disorder largely mediated by type I and II interferon (IFN). The potential contribution of innate immune cells, such as natural killer (NK) cells and dendritic cells (DC), to the pSS pathology remains understudied. Here, we identified an enriched CD16+ CD56hi NK cell subset associated with higher cytotoxic function, as well as elevated proportions of inflammatory CD64+ conventional dendritic cell (cDC2) subtype that expresses increased levels of MICa/b, the ligand for the activating receptor NKG2D, in pSS individuals. Circulating cDC2 from pSS patients efficiently induced activation of cytotoxic NK cells ex vivo and were found in proximity to CD56+ NK cells in salivary glands (SG) from pSS patients. Interestingly, transcriptional activation of IFN signatures associated with the RIG-I/DDX60 pathway, IFN I receptor, and its target genes regulate the expression of NKG2D ligands on cDC2 from pSS patients. Finally, increased proportions of CD64hi RAE-1+ cDC2 and NKG2D+ CD11b+ CD27+ NK cells were present in vivo in the SG after poly I:C injection. Our study provides novel insight into the contribution and interplay of NK and cDC2 in pSS pathology and identifies new potential therapy targets.

Dual targeted therapy in patients with psoriatic arthritis and spondyloarthritis: a real-world multicenter experience from Spain.

Dual targeted therapy (DTT) has emerged as a promising approach in patients with refractory spondyloarthritis (SpA) or psoriatic arthritis (PsA) and extra-musculoskeletal manifestations of both diseases, but its effectiveness/safety ratio still remains unclear. This is a retrospective, real-world multicenter study in refractory SpA and PsA patients with simultaneous use of two biological or synthetic targeted agents. Effectiveness was assessed using Ankylosing Spondylitis Disease Activity Score with C-reactive protein (ASDAS-CRP) and Disease Activity in Psoriatic Arthritis (DAPSA) Score. We identified 39 different DTT combinations in 36 patients (22 SpA; 14 PsA), 25 of them with concomitant inflammatory bowel disease. The most commonly used combinations were TNF inhibitor plus antagonist of the IL12/23 pathway, followed by TNF inhibitor plus IL-17 antagonist. During a median exposure of 14.86 months (IQR 8-20.2), DTT retention rate was 69.4% (n=25/36; 19 SpA, 6 PsA). Major clinical improvement (change in ASDAS-CRP > 2 or improvement > 85% in DAPSA) was achieved in 69.4% of patients (n=25/36 therapeutical combinations; 17/21 SpA, 8/15 PsA), with a 58.3% (n=21/36 combinations; 15/20 SpA, 6/13 PsA) low-activity/remission rate. Of the patients who were receiving glucocorticoids, 55% managed to withdraw them during follow-up. Interestingly, only four serious adverse events in three patients were observed, leading to DTT discontinuation.

Positron Emission Computed Tomography Spectrum of Large Vessel Vasculitis in a Tertiary Center: Differences in 18F-fluorodeoxyglucose Uptake between Large Vessel Vasculitis with Predominant Cranial and Extracranial Giant Cell Arteritis Phenotypes.

(1) Objective:To assess the spectrum of PET-CT-related large vessel vasculitis (LVV) in a Spanish tertiary center and to determine whether FDG uptake by PET-CT differs between giant cell arteritis (GCA) with predominant cranial or extracranial phenotypes. (2) Methods: The spectrum of patients diagnosed with LVV by PET-CT in a tertiary referral hospital that cares for 450,000 people over a period of two years was reviewed. Moreover, differences in FDG uptake between LVV-GCA with predominantly cranial and extracranial phenotype were analyzed. (3) Results: Eighty patients were diagnosed with LVV by PET-CT. Most were due to systemic vasculitis (n = 64; 80%), especially GCA (n = 54; 67.5%). Other conditions included the presence of rheumatic diseases (n = 4; 3.2%), tumors (n = 9; 7.2%) and infections (n = 3; 2.4%). LVV-GCA patients with predominant extracranial GCA phenotype were younger (mean ± SD: 68.07 ± 9.91 vs. 75.46 ± 7.64 years; p = 0.017) and had a longer delay to the diagnosis (median [interquartile range] 12 [4-18] vs. 4 [3-8]; p = 0.006), but had polymyalgia rheumatica symptoms more frequently than those with predominantly cranial GCA phenotype (46.3% vs. 15.4%, p = 0.057). When FDG uptake was compared according to the two different disease patterns, no statistically significant differences were observed. However, patients with extracranial LVV-GCA showed a non-significantly higher frequency of vasculitic involvement of lower-extremity arteries. (4) Conclusions: Regardless of the predominant phenotype, LVV identified by PET-CT is more commonly due to GCA in the Spanish population. In these GCA patients, younger age, PMR, and a higher frequency of lower-extremity artery vasculitis suggest the presence of LVV.

Occurrence of SARS-CoV-2 viremia is associated with genetic variants of genes related to COVID-19 pathogenesis.

Introduction: SARS-CoV-2 viral load has been related to COVID-19 severity. The main aim of this study was to evaluate the relationship between SARS-CoV-2 viremia and SNPs in genes previously studied by our group as predictors of COVID-19 severity. Materials and methods: Retrospective observational study including 340 patients hospitalized for COVID-19 in the University Hospital La Princesa between March 2020 and December 2021, with at least one viremia determination. Positive viremia was considered when viral load was above the quantifiable threshold (20 copies/ml). A total of 38 SNPs were genotyped. To study their association with viremia a multivariate logistic regression was performed. Results: The mean age of the studied population was 64.5 years (SD 16.6), 60.9% patients were male and 79.4% white non-Hispanic. Only 126 patients (37.1%) had at least one positive viremia. After adjustment by confounders, the presence of the minor alleles of rs2071746 (HMOX1; T/T genotype OR 9.9 p < 0.0001), rs78958998 (probably associated with SERPING1 expression; A/T genotype OR 2.3, p = 0.04 and T/T genotype OR 12.9, p < 0.0001), and rs713400 (eQTL for TMPRSS2; C/T + T/T genotype OR 1.86, p = 0.10) were associated with higher risk of viremia, whereas the minor alleles of rs11052877 (CD69; A/G genotype OR 0.5, p = 0.04 and G/G genotype OR 0.3, p = 0.01), rs2660 (OAS1; A/G genotype OR 0.6, p = 0.08), rs896 (VIPR1; T/T genotype OR 0.4, p = 0.02) and rs33980500 (TRAF3IP2; C/T + T/T genotype OR 0.3, p = 0.01) were associated with lower risk of viremia. Conclusion: Genetic variants in HMOX1 (rs2071746), SERPING1 (rs78958998), TMPRSS2 (rs713400), CD69 (rs11052877), TRAF3IP2 (rs33980500), OAS1 (rs2660) and VIPR1 (rs896) could explain heterogeneity in SARS-CoV-2 viremia in our population.

Mucosal Immune Defence Gene Polymorphisms as Relevant Players in the Pathogenesis of IgA Vasculitis?

ITGAM-ITGAX (rs11150612, rs11574637), VAV3 rs17019602, CARD9 rs4077515, DEFA (rs2738048, rs10086568), and HORMAD2 rs2412971 are mucosal immune defence polymorphisms, that have an impact on IgA production, described as risk loci for IgA nephropathy (IgAN). Since IgAN and Immunoglobulin-A vasculitis (IgAV) share molecular mechanisms, with the aberrant deposit of IgA1 being the main pathophysiologic feature of both entities, we assessed the potential influence of the seven abovementioned polymorphisms on IgAV pathogenesis. These seven variants were genotyped in 381 Caucasian IgAV patients and 997 matched healthy controls. No statistically significant differences were observed in the genotype and allele frequencies of these seven polymorphisms when the whole cohort of IgAV patients and those with nephritis were compared to controls. Similar genotype and allele frequencies of all polymorphisms were disclosed when IgAV patients were stratified according to the age at disease onset or the presence/absence of gastrointestinal or renal manifestations. Likewise, no ITGAM-ITGAX and DEFA haplotype differences were observed when the whole cohort of IgAV patients, along with those with nephritis and controls, as well as IgAV patients, stratified according to the abovementioned clinical characteristics, were compared. Our results suggest that mucosal immune defence polymorphisms do not represent novel genetic risk factors for IgAV pathogenesis.