Significance of clinical-immunological patterns and diagnostic yield of biopsies in microscopic polyangiitis and granulomatosis with polyangiitis.

BACKGROUND: Microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA) are the two major antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). OBJECTIVES: To characterize a homogenous AAV cohort and to assess the impact of clinicopathological profiles and ANCA serotypes on clinical presentation and prognosis. Clinical differences in GPA patients according to ANCA serotype and the diagnostic yield for vasculitis of biopsies in different territories were also investigated. RESULTS: This retrospective study (2000-2021) included 152 patients with AAV (77 MPA/75 GPA). MPA patients (96.1% myeloperoxidase [MPO]-ANCA and 2.6% proteinase 3 [PR3]-ANCA) presented more often with weight loss, myalgia, renal involvement, interstitial lung disease (ILD), cutaneous purpura, and peripheral nerve involvement. Patients with GPA (44% PR3-ANCA, 33.3% MPO, and 22.7% negative/atypical ANCA) presented more commonly with ear, nose, and throat and eye/orbital manifestations, more relapses, and higher survival than patients with MPA. GPA was the only independent risk factor for relapse. Poor survival predictors were older age at diagnosis and peripheral nerve involvement. ANCA serotypes differentiated clinical features in a lesser degree than clinical phenotypes. A mean of 1.5 biopsies were performed in 93.4% of patients in different territories. Overall, vasculitis was identified in 80.3% (97.3% in MPA and 61.8% in GPA) of patients. CONCLUSIONS: The identification of GPA presentations associated with MPO-ANCA and awareness of risk factors for relapse and mortality are important to guide proper therapeutic strategies in AAV patients. Biopsies of different affected territories should be pursued in difficult-to-diagnose patients based on their significant diagnostic yield.

Statin use and myopathy. Not always guilty.

OBJECTIVES: Statins are the cornerstone of the treatment and prevention of cardiovascular disease but have been associated with muscular side effects, among others. If patients are not properly evaluated, statin discontinuation may take place, leaving patients' symptoms unresolved and precluding an effective cardiovascular treatment. The present study aims to describe the clinical characteristics, the diagnostic process and the final diagnosis of selected patients with suspected statin-induced myopathy, with quite different alternative diagnoses. METHODS: Among the 86 patients referred to our unit for evaluation since 2012, 6 patients with suspected statin-induced myopathy that was finally ruled out were selected as examples because of their illustrative value. All patients were evaluated in a Muscular Diseases Unit by myology experts, and additional testing was performed according to clinical suspicion. RESULTS: Of the six selected patients with suspected statin-induced myopathy, three had a neurogenic aetiology, two had vacuolar myopathies and one had severe hypothyroidism. Statins were permanently discontinued in two cases, with the treatment of one of the latter patients being continued with a protein convertase subtilisin/kexin type 9 (PCSK9) inhibitor. CONCLUSION: Not all patients taking statins who develop muscle complaints have statin-related myopathy. A thorough clinical evaluation and appropriate testing is warranted to avoid an unnecessary increase in cardiovascular risk.

Mitochondrial implications in human pregnancies with intrauterine growth restriction and associated cardiac remodelling.

Intrauterine growth restriction (IUGR) is an obstetric complication characterised by placental insufficiency and secondary cardiovascular remodelling that can lead to cardiomyopathy in adulthood. Despite its aetiology and potential therapeutics are poorly understood, bioenergetic deficits have been demonstrated in adverse foetal and cardiac development. We aimed to evaluate the role of mitochondria in human pregnancies with IUGR. In a single-site, cross-sectional and observational study, we included placenta and maternal peripheral and neonatal cord blood mononuclear cells (PBMC and CBMC) from 14 IUGR and 22 control pregnancies. The following mitochondrial measurements were assessed: enzymatic activities of mitochondrial respiratory chain (MRC) complexes I, II, IV, I + III and II + III, oxygen consumption (cell and complex I-stimulated respiration), mitochondrial content (citrate synthase [CS] activity and mitochondrial DNA copy number), total ATP levels and lipid peroxidation. Sirtuin3 expression was evaluated as a potential regulator of bioenergetic imbalance. Intrauterine growth restriction placental tissue showed a significant decrease of MRC CI enzymatic activity (P < 0.05) and CI-stimulated oxygen consumption (P < 0.05) accompanied by a significant increase of Sirtuin3/ß-actin protein levels (P < 0.05). Maternal PBMC and neonatal CBMC from IUGR patients presented a not significant decrease in oxygen consumption (cell and CI-stimulated respiration) and MRC enzymatic activities (CII and CIV). Moreover, CS activity was significantly reduced in IUGR new-borns (P < 0.05). Total ATP levels and lipid peroxidation were preserved in all the studied tissues. Altered mitochondrial function of IUGR is especially present at placental and neonatal level, conveying potential targets to modulate obstetric outcome through dietary interventions aimed to regulate Sirtuin3 function.

Imbalance in mitochondrial dynamics and apoptosis in pregnancies among HIV-infected women on HAART with obstetric complications.

Background: HIV infection and HAART trigger genetic and functional mitochondrial alterations leading to cell death and adverse clinical manifestations. Mitochondrial dynamics enable mitochondrial turnover and degradation of damaged mitochondria, which may lead to apoptosis. Objectives: To evaluate markers of mitochondrial dynamics and apoptosis in pregnancies among HIV-infected women on HAART and determine their potential association with obstetric complications. Methods: This controlled, single-site, observational study without intervention included 26 HIV-infected pregnant women on HAART and 18 control pregnancies and their newborns. Maternal PBMCs and neonatal cord blood mononuclear cells (CBMCs) were isolated at the first trimester of gestation and at delivery. The placenta was homogenized at 5% w/v. Mitochondrial dynamics, fusion events [mitofusin 2 (Mfn2)/ß-actin] and fission events [dynamin-related protein 1 (Drp1/ß-actin)] and apoptosis (caspase 3/ß-actin) were assessed by western blot analysis. Results: Obstetric complications were significantly more frequent in pregnancies among HIV-infected women [OR 5.00 (95% CI 1.21-20.70)]. Mfn2/ß-actin levels in PBMCs from controls significantly decreased during pregnancy (202.13 ±â€¯57.45%), whereas cases maintained reduced levels from the first trimester of pregnancy and no differences were observed in CBMCs. Mfn2/ß-actin and Drp1/ß-actin contents significantly decreased in the placenta of cases. Caspase 3/ß-actin levels significantly increased during pregnancy in PBMCs of cases (50.00 ±â€¯7.89%), remaining significantly higher than in controls. No significant differences in caspase 3/ß-actin content of neonatal CBMCs were observed, but there was a slight increased trend in placenta from cases. Conclusions: HIV- and HAART-mediated mitochondrial damage may be enhanced by decreased mitochondrial dynamics and increased apoptosis in maternal and placental compartments but not in the uninfected fetus. However, direct effects on mitochondrial dynamics and implication of apoptosis were not demonstrated in adverse obstetric outcomes.

Pyruvate kinase M2 and the mitochondrial ATPase Inhibitory Factor 1 provide novel biomarkers of dermatomyositis: a metabolic link to oncogenesis.

BACKGROUND: Metabolic alterations play a role in the development of inflammatory myopathies (IMs). Herein, we have investigated through a multiplex assay whether proteins of energy metabolism could provide biomarkers of IMs. METHODS: A cohort of thirty-two muscle biopsies and forty plasma samples comprising polymyositis (PM), dermatomyositis (DM) and sporadic inclusion body myositis (sIBM) and control donors was interrogated with monoclonal antibodies against proteins of energy metabolism using reverse phase protein microarrays (RPPA). RESULTS: When compared to controls the expression of the proteins is not significantly affected in the muscle of PM patients. However, the expression of ß-actin is significantly increased in DM and sIBM in consistence with muscle and fiber regeneration. Concurrently, the expression of some proteins involved in glucose metabolism displayed a significant reduction in muscle of sIBM suggesting a repression of glycolytic metabolism in these patients. In contrasts to these findings, the expression of the glycolytic pyruvate kinase isoform M2 (PKM2) and of the mitochondrial ATPase Inhibitor Factor 1 (IF1) and Hsp60 were significantly augmented in DM when compared to other IMs in accordance with a metabolic shift prone to cancer development. PKM2 alone or in combination with other biomarkers allowed the discrimination of control and IMs with very high (>95%) sensitivity and specificity. Unfortunately, plasma levels of PKM2 were not significantly altered in DM patients to recommend its use as a non-invasive biomarker of the disease. CONCLUSIONS: Expression of proteins of energy metabolism in muscle enabled discrimination of patients with IMs. RPPA identified the glycolysis promoting PKM2 and IF1 proteins as specific biomarkers of dermatomyositis, providing a biochemical link of this IM with oncogenesis.

Molecular basis of reduced birth weight in smoking pregnant women: mitochondrial dysfunction and apoptosis.

In utero exposure of fetuses to tobacco is associated with reduced birth weight. We hypothesized that this may be due to the toxic effect of carbon monoxide (CO) from tobacco, which has previously been described to damage mitochondria in non-pregnant adult smokers. Maternal peripheral blood mononuclear cells (PBMCs), newborn cord blood mononuclear cells (CBMCs) and placenta were collected from 30 smoking pregnant women and their newborns and classified as moderate and severe smoking groups, and compared to a cohort of 21 non-smoking controls. A biomarker for tobacco consumption (cotinine) was assessed by ELISA (enzyme-linked immunosorbent assay). The following parameters were measured in all tissues: mitochondrial chain complex IV [cytochrome c oxidase (COX)] activity by spectrophotometry, mitochondrial DNA levels by reverse transcription polymerase chain reaction, oxidative stress by spectrophotometric lipid peroxide quantification, mitochondrial mass through citrate synthase spectrophotometric activity and apoptosis by Western blot parallelly confirmed by TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labelling) assay in placenta. Newborns from smoking pregnant women presented reduced birth weight by 10.75 percent. Materno-fetal mitochondrial and apoptotic PBMC and CBMC parameters showed altered and correlated values regarding COX activity, mitochondrial DNA, oxidative stress and apoptosis. Placenta partially compensated this dysfunction by increasing mitochondrial number; even so ratios of oxidative stress and apoptosis were increased. A CO-induced mitotoxic and apoptotic fingerprint is present in smoking pregnant women and their newborn, with a lack of filtering effect from the placenta. Tobacco consumption correlated with a reduction in birth weight and mitochondrial and apoptotic impairment, suggesting that both could be the cause of the reduced birth weight in smoking pregnant women.

Polymyositis, a very uncommon isolated disease: clinical and histological re-evaluation after long-term follow-up.

The aim of the present study was to explore whether polymyositis may be considered as an isolated, organ-specific disease or more suitably as a secondary or associated entity. A retrospective re-evaluation of all the muscle biopsies performed at the Hospital Clínic of Barcelona showing histopathological pattern of polymyositis from January 1997 to May 2012 was carried out. The medical records of the patients with the aforementioned pathological pattern were also reviewed. From 1.290 muscle biopsies performed during the period evaluated, 36 with polymyositis pattern were identified. At the time of muscle biopsy, polymyositis pattern was secondary or associated with other disease in 26 patients and was classified as isolated in the remaining ten patients. After pathological re-evaluation and long-term clinical follow-up, only one patient remained with this diagnosis. Overall, the main final diagnosis related to the initial polymyositis pattern was inflammatory myopathy associated with connective tissue disease. Several other associated conditions were also identified. Isolated polymyositis is highly uncommon. Ruling out potential associated or confusing entities, like inclusion body myositis, overlap syndromes, infections, and cancer, is mandatory.

Positron emission tomography assessment of large vessel inflammation in patients with newly diagnosed, biopsy-proven giant cell arteritis: a prospective, case-control study.

BACKGROUND: Positron emission tomography (PET) scan is emerging as a promising imaging technique to detect large-vessel inflammation in giant cell arteritis (GCA). However, the lack of a standardised definition of arteritis based on (18)fluorodeoxyglucose (FDG) uptake is an important limitation to the use of PET scan for diagnostic purposes. OBJECTIVE: To prospectively assess the intensity and distribution of FDG uptake at different vascular territories in patients with newly diagnosed GCA compared with controls. METHODS: 32 consecutive, biopsy-proven, GCA patients treated with glucocorticoids for ≤3 days were included. The control group consisted of 20 individuals, who underwent PET/CT for cancer staging. Maximal standardised uptake value (SUVm) was calculated at four aortic segments, supraaortic branches and iliac-femoral territory. Sensitivity and specificity was calculated by receiver-operator characteristic curves (ROC) analysis. RESULTS: Mean SUVm was significantly higher in patients than in controls in all vessels explored and correlated with acute-phase reactants and serum IL-6. Mean of the SUVm at all the vascular territories had an area under the curve (AUC) of 0.830, and a cut-off of 1.89 yielded a sensitivity of 80% and a specificity of 79% for GCA diagnosis. There were no significant differences in AUC among the vascular beds examined. CONCLUSIONS: FDG uptake by large vessels has a substantial sensitivity and specificity for GCA diagnosis.

Increased IL-17A expression in temporal artery lesions is a predictor of sustained response to glucocorticoid treatment in patients with giant-cell arteritis.

BACKGROUND: Interleukin 17A (IL-17A) exerts pivotal proinflammatory functions in chronic inflammatory and autoimmune diseases. OBJECTIVE: To investigate IL-17A expression in temporal artery lesions from patients with giant-cell arteritis (GCA), and its relationship with disease outcome. METHODS: Fifty-seven patients with biopsy-proven GCA were prospectively evaluated, treated and followed for 4.5 years (52-464 weeks). Relapses, time (weeks) required to achieve a maintenance prednisone dose <10 mg/day, and time (weeks) to complete prednisone withdrawal were prospectively recorded. IL-17A mRNA was measured by real-time quantitative RT-PCR in temporal arteries from all patients and 19 controls. IL-17 protein expression was assessed by immunohistochemistry/immunofluorescence. RESULTS: IL-17A expression was significantly increased in temporal artery samples from GCA patients compared with controls (6.22±8.61 vs 2.50±3.9 relative units, p=0.016). Surprisingly, patients with strong IL-17A expression tended to experience less relapses, and required significantly shorter treatment periods (median 25 vs 44 weeks to achieve <10 mg prednisone/day, p=0.0079). There was no correlation between IL-17A and RORc or RORα expression suggesting that these transcription factors may not exclusively reflect Th17 differentiation, and that cells other than Th17 cells might contribute to IL-17 expression in active patients. Accordingly, FoxP3(+)IL-17A(+) cells were identified in lesions by confocal microscopy and were dramatically reduced in specimens from treated patients. CONCLUSIONS: IL-17A expression is increased in GCA lesions, and is a predictor of response to glucocorticoid treatment. The contribution of FoxP3+ cells to IL-17A production in untreated patients suggests that induced-Tregs may facilitate disease remission when proinflammatory cytokine production is downregulated by glucocorticosteroids.

Dermatomyositis unleashed by immune checkpoint inhibitors. Three additional cases and a review of the literature.

OBJECTIVES: Immune checkpoint inhibitors (ICI) have revolutionized the treatment of several locally advanced and metastatic tumors. They enhance the effector function of the immune system, consequently leading to different immune-related adverse events. The aim of the present study was to describe three cases of dermatomyositis (DM) triggered by ICI diagnosed at our institution and to perform a review of the literature. METHODS: We performed a retrospective clinical, laboratory, and pathological evaluation of three cases of DM triggered by ICI belonging to a cohort of 187 DM patients from the Clinic Hospital Muscle Research Group of Barcelona from January 2009 to July 2022. Moreover, we undertook a narrative review of the literature from January 1990 to June 2022. RESULTS: Cases from our institution were triggered by avelumab, an anti-PD-1 ligand (PD-L1), nivolumab, and pembrolizumab, both anti-programmed death-1 (PD-1). One of these patients had locally advanced melanoma, and two had urothelial carcinoma. The severity and response to treatment were heterogeneous among the different cases. All were positive at high titers for anti-TIF1γ autoantibodies; in one of them, serum before the onset of ICI was available, and anti-TIF1γ autoantibodies were already present. RNA expression of IFNB1, IFNG and genes stimulated by these cytokines were markedly elevated in these patients. CONCLUSIONS: In conclusion, data from our patients and the narrative review suggest that early positivity to anti-TIF1γ unleashed by ICI may play a role in the development of full-blown DM, at least in some cases.

Large vessel involvement in biopsy-proven giant cell arteritis: prospective study in 40 newly diagnosed patients using CT angiography.

BACKGROUND: Necroscopic and surgical studies have suggested that giant cell arteritis (GCA) may target the aorta and its main branches. Imaging techniques are able to detect large vessel vasculitis (LVV) non-invasively in patients, but the prevalence of LVV in GCA has not been clearly established. OBJECTIVE: To assess prospectively the prevalence, characteristics and topography of LVV in patients with newly diagnosed GCA and to determine the associated clinical and laboratory features. METHODS: CT angiography (CTA) was performed in 40 consecutive patients with newly diagnosed biopsy-proven GCA. Patients were treatment-naïve or had been treated with corticosteroids for <3 days. Vessel wall thickness and vessel diameter (dilation or stenoses) at four aortic segments (ascending aorta, aortic arch, descending thoracic and abdominal aorta) and at the main aortic branches were evaluated. RESULTS: LVV was detected in 27 patients (67.5%). The vessels involved were as follows: aorta (26 patients, 65%), brachiocephalic trunk (19 patients, 47.5%), carotid arteries (14 patients, 35%), subclavian arteries (17 patients, 42.5%), axillary arteries (7 patients, 17.5%), splanchnic arteries (9 patients, 22.5%), renal arteries (3 patients, 7.5%), iliac arteries (6 patients, 15%) and femoral arteries (11 patients, 30%). Dilation of the thoracic aorta was already present in 6 patients (15%). Cranial ischaemic events were significantly less frequent in patients with LVV (p=0.029). Treatment-naïve patients had a higher frequency of LVV (77% vs 29%, p=0.005). CONCLUSIONS: CTA-defined LVV occurs in two-thirds of patients with GCA at the time of diagnosis and aortic dilation is already present in 15%. Previous corticosteroid treatment may decrease CTA-detected LVV.

Expression and Function of IL12/23 Related Cytokine Subunits (p35, p40, and p19) in Giant-Cell Arteritis Lesions: Contribution of p40 to Th1- and Th17-Mediated Inflammatory Pathways.

Background: Giant-cell arteritis (GCA) is considered a T helper (Th)1- and Th17-mediated disease. Interleukin (IL)-12 is a heterodimeric cytokine (p35/p40) involved in Th1 differentiation. When combining with p19 subunit, p40 compose IL-23, a powerful pro-inflammatory cytokine that maintains Th17 response. Objectives: The aims of this study were to investigate p40, p35, and p19 subunit expression in GCA lesions and their combinations to conform different cytokines, to assess the effect of glucocorticoid treatment on subunit expression, and to explore functional roles of p40 by culturing temporal artery sections with a neutralizing anti-human IL-12/IL-23p40 antibody. Methods and results: p40 and p19 mRNA concentrations measured by real-time RT-PCR were significantly higher in temporal arteries from 50 patients compared to 20 controls (4.35 ± 4.06 vs 0.51 ± 0.75; p < 0.0001 and 20.32 ± 21.78 vs 4.17 ± 4.43 relative units; p < 0.0001, respectively). No differences were found in constitutively expressed p35 mRNA. Contrarily, p40 and p19 mRNAs were decreased in temporal arteries from 16 treated GCA patients vs those from 34 treatment-naïve GCA patients. Accordingly, dexamethasone reduced p40 and p19 expression in cultured arteries. Subunit associations to conform IL-12 and IL-23 were confirmed by proximity-ligation assay in GCA lesions. Immunofluorescence revealed widespread p19 and p35 expression by inflammatory cells, independent from p40. Blocking IL-12/IL-23p40 tended to reduce IFNγ and IL-17 mRNA production by cultured GCA arteries and tended to increase Th17 inducers IL-1ß and IL-6. Conclusion: IL-12 and IL-23 heterodimers are increased in GCA lesions and decrease with glucocorticoid treatment. p19 and p35 subunits are much more abundant than p40, indicating an independent role for these subunits or their potential association with alternative subunits. The modest effect of IL-12/IL-23p40 neutralization may indicate compensation by redundant cytokines or cytokines resulting from alternative combinations.

Development of ischemic complications in patients with giant cell arteritis presenting with apparently isolated polymyalgia rheumatica: study of a series of 100 patients.

Several studies suggest that patients with giant cell arteritis (GCA) presenting with isolated polymyalgia rheumatica (PMR) with no cranial symptoms are at low risk of suffering GCA-related ischemic events. However, the issue remains controversial. In the current study we assessed the development of ischemic events in a large series of GCA patients who suffered from apparently isolated PMR during the main course of their disease. One hundred GCA patients presenting with PMR only for at least 2 months were selected from among 347 individuals with biopsy-proven GCA. Clinical manifestations and their chronologic appearance before diagnosis were recorded. Seventy-three patients presented with isolated PMR for a median of 8 months (range, 2 mo-5 yr) and later developed cranial symptoms for a median of 3 weeks (range, 0 wk-1 yr), which eventually led to GCA diagnosis (Group 1). The remaining 27 patients, after presenting a self-limiting course of dismissed mild cranial symptoms lasting for a median of 2 weeks (range, 1 wk-4 mo), developed PMR, which was their chief complaint for a median of 3 months (range, 2 mo-1.5 yr) and the reason for medical evaluation (Group 2). Twenty (27.4%) patients in Group 1 suffered disease-related ischemic complications at the time of diagnosis. No patient in Group 2 developed ischemic events. Patients with GCA presenting with apparently isolated PMR are not a benign subset and have a significant risk of developing ischemic complications. Among them, the only patients who appear to be at low risk of developing ischemic events are those in whom a self-limiting episode of cranial symptoms can be recorded.

Camptocormia as a clinical manifestation of mitochondrial myopathy.

Camptocormia is an unusual condition characterized by a progressive weakness of the extensor muscles of the spine that cause an involuntary truncal flexion. Occasionally, camptocormia can be the clinical manifestation of an underlying myopathy, including inflammatory or metabolic myopathies. We present a case of a 78-year-old female with camptocormia associated with a mitochondrial myopathy. Additionally, we review the clinical characteristics of three similar, previously reported cases.

RIG-I expression in perifascicular myofibers is a reliable biomarker of dermatomyositis.

BACKGROUND: Dermatomyositis (DM) is inflammatory myopathy or myositis characterized by muscle weakness and skin manifestations. In the differential diagnosis of DM the evaluation of the muscle biopsy is of importance among other parameters. Perifascicular atrophy in the muscle biopsy is considered a hallmark of DM. However, perifascicular atrophy is not observed in all patients with DM and, conversely, perifascicular atrophy can be observed in other myositis such as antisynthetase syndrome (ASS), complicating DM diagnosis. Retinoic acid inducible-gene I (RIG-I), a receptor of innate immunity that promotes type I interferon, was observed in perifascicular areas in DM. We compared the value of RIG-I expression with perifascicular atrophy as a biomarker of DM. METHODS: We studied by immunohistochemical analysis the expression of RIG-I and the presence of perifascicular atrophy in 115 coded muscle biopsies: 44 patients with DM, 18 with myositis with overlap, 8 with ASS, 27 with non-DM inflammatory myopathy (16 with polymyositis, 6 with inclusion body myositis, 5 with immune-mediated necrotizing myopathy), 8 with muscular dystrophy (4 with dysferlinopathy, 4 with fascioscapulohumeral muscle dystrophy) and 10 healthy controls. RESULTS: We found RIG-I-positive fibers in 50% of DM samples vs 11% in non-DM samples (p < 0.001). Interestingly, RIG-I staining identified 32% of DM patients without perifascicular atrophy (p = 0.007). RIG-I sensitivity was higher than perifascicular atrophy (p < 0.001). No differences in specificity between perifascicular atrophy and RIG-I staining were found (92% vs 88%). RIG-I staining was more reproducible than perifascicular atrophy (κ coefficient 0.52 vs 0.37). CONCLUSIONS: The perifascicular pattern of RIG-I expression supports the diagnosis of DM. Of importance for clinical and therapeutic studies, the inclusion of RIG-I in the routine pathological staining of samples in inflammatory myopathy will allow us to gather more homogeneous subgroups of patients in terms of immunopathogenesis.

Description and Validation of Histological Patterns and Proposal of a Dynamic Model of Inflammatory Infiltration in Giant-cell Arteritis.

The extent of inflammatory infiltrates in arteries from patients with giant-cell arteritis (GCA) have been described using different terms and definitions. Studies investigating the relationship between GCA histological features and clinical manifestations have produced controversial results. The aims of this study were to characterize and validate histological patterns in temporal artery biopsies (TABs) from GCA patients, to explore additional histological features, including the coexistence of different patterns, and also to investigate the relationship of the inflammatory patterns with clinical and laboratory features.We performed histological examination of TAB from patients with GCA consecutively diagnosed between 1992 and 2012. Patterns of inflammation were defined according to the extent and distribution of inflammatory infiltrates within the artery. Clinical and laboratory variables were recorded. Two external investigators underwent a focused, one-day training session and then independently scored 77 cases. Quadratic-weighted kappa was calculated.TAB from 285 patients (200 female/85 male) were evaluated. Four histological inflammatory patterns were distinguished: 1 - adventitial (n = 16); 2 - adventitial invasive: adventitial involvement with some extension to the muscular layer (n = 21); 3 - concentric bilayer: adventitial and intimal involvement with media layer preservation (n = 52); and 4 - panarteritic (n = 196). Skip lesions were observed in 10% and coexistence of various patterns in 43%. Raw agreement of each external scorer with the gold-standard was 82% and 77% (55% and 46% agreement expected from chance); kappa = 0.82 (95% confidence interval [CI] 0.70-0.95) and 0.79 (95% CI 0.68-0.91). Although abnormalities on temporal artery palpation and the presence of jaw claudication and scalp tenderness tended to occur more frequently in patients with arteries depicting more extensive inflammation, no statistically significant correlations were found between histological patterns and clinical features or laboratory findings.In conclusion, we have described and validated 4 histological patterns. The presence of different coexisting patterns likely reflects sequential steps in the progression of inflammation and injury. No clear relationship was found between these patterns and clinical or laboratory findings. However, several cranial manifestations tended to occur more often in patients with temporal arteries exhibiting panarteritic inflammation. This validated score system may be useful to standardize stratification of histological severity for immunopathology biomarker studies or correlation with imaging.

Clinical and genetic characterization of the autoinflammatory diseases diagnosed in an adult reference center.

INTRODUCTION: Autoinflammatory diseases (AID) are usually diagnosed during the pediatric age. However, adult-onset disease or diagnosis during adulthood has been occasionally described. OBJECTIVES: To assess the clinical and genetic characteristics of adult patients diagnosed with an AID in an adult referral center for AID. METHODS: We retrospectively evaluated clinical and genetic features of adult patients (≥16 years) diagnosed with an AID or referred after AID diagnosis to the Clinical Unit of AID, at the Department of Autoimmune Diseases, Hospital Clínic of Barcelona, from 2008 to 2014. RESULTS: During the study period, a genetic study for suspected AID was requested to 90 patients at the Department of Autoimmune Diseases. A final diagnosis of monogenic AID was achieved in 17 patients (19% of patients tested). Five additional cases were diagnosed with periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA) syndrome and 10 patients with AID were referred from other adult departments. Finally, a total of 32 patients with AID were finally diagnosed or monitored in our Clinical Unit. These included 12 (37.5%) familial Mediterranean fever, 6 (18.8%) tumour necrosis factor-receptor associated periodic syndrome, 8 (25%) cryopirin-associated periodic syndromes (Muckle-Wells syndrome [MWS] or overlap familial cold-associated periodic syndrome/MWS), 1 (3.1%) mevalonate kinase deficiency, and 5 (15.6%) PFAPA. Clinical evidence of disease-onset during childhood and adulthood was observed in 15 (47%) and 17 (53%) patients, respectively. Overall, the final diagnosis was obtained after a delay of a mean of 12 years (range 0-47 years). Compared to children, adult patients with AID in our series presented more frequently with non-severe manifestations and none of them developed amyloidosis during follow-up. Adult patients also carried higher proportion of low-penetrance mutations or polymorphisms and all genetic variants were presented in heterozygosis or as heterozygous compounds. CONCLUSIONS: Adult disease-onset or delayed diagnosis of AID during adulthood is associated with milder disease phenotypes, and seem to be driven by mild genotypes, with predominant presence of low-penetrance mutations or polymorphisms.