Federica Maritati

IgG4 immune response in Churg–Strauss syndrome

Objective T-helper type 2 responses are crucial in Churg–Strauss syndrome (CSS) and may enhance the production of IgG4 antibodies. The authors assessed the IgG4 immune response in CSS patients. Methods The authors included 46 consecutive patients with CSS (24 with active and 22 with quiescent disease), 26 with granulomatosis with polyangiitis (GPA, Wegeners), 25 with atopic asthma and 20 healthy controls and determined serum IgG, IgM, IgA, IgE and IgG subclass levels. Tissue infiltration by IgG4 plasma cells was assessed in nine patients with CSS, 10 with GPA, 22 with chronic sinusitis (11 with and 11 without eosinophilia). Results IgG4 levels were markedly higher in active CSS patients than in controls (p<0.001 vs all control groups). Serum IgG4 correlated with the number of disease manifestations (r=0.52, p=0.01) and the Birmingham vasculitis activity score (r=0.64, p=0.001). Longitudinal analysis in 12 CSS cases showed that both the IgG4 level and IgG4/IgG ratio dropped during disease remission (p=3×10−5 and p=6×10−4, respectively). Tissue analysis did not show an increased IgG4 plasma cell infiltration in CSS biopsies compared with control groups. Conclusions Serum IgG4 levels are markedly elevated in active CSS and correlate with the number of organ manifestations and disease activity.

PTPN22 R620W polymorphism in the ANCA-associated vasculitides

OBJECTIVES PTPN22 is involved in T-cell activation and its R620W single-nucleotide polymorphism (SNP) has been shown to predispose to different autoimmune diseases. The aims of this study were to investigate the role of the PTPN22 R620W SNP in conferring susceptibility to the ANCA-associated vasculitides (AAVs), and to explore potential associations between the PTPN22 genotype and the disease manifestations. METHODS PTPN22 R620W SNP was genotyped in a cohort of 344 AAV patients [143 with granulomatosis with polyangiitis (Wegeners) (GPA), 102 with microscopic polyangiitis (MPA) and 99 with Churg-Strauss syndrome (CSS)] and in 945 healthy controls. RESULTS The frequency of the minor allele (620W) was significantly higher in GPA patients than in controls [P = 0.005, χ(2 )= 7.858, odds ratio (OR) = 1.91], while no statistically significant association was found with MPA or CSS. Among GPA patients, the 620W allele was particularly enriched in ANCA-positive patients as compared with controls (P = 0.00012, χ(2 )= 14.73, OR = 2.31); a particularly marked association was also found with ENT involvement (P = 0.0071, χ(2 )= 7.258, OR = 1.98), lung involvement (P = 0.0060, χ(2 )= 7.541, OR = 2.07) and skin manifestations of all kinds (P = 0.000047, χ(2 )= 16.567, OR = 3.73). CONCLUSION The PTPN22 620W allele confers susceptibility to the development of GPA (but not of MPA or CSS), and particularly of its ANCA-positive subset.

Rituximab therapy for chronic periaortitis

Chronic periaortitis (CP) is a rare condition, hallmarked by periaortic fibro-inflammatory tissue which often causes ureteral obstruction, and encompasses idiopathic retroperitoneal fibrosis and inflammatory abdominal aortic aneurysm (IAAA). CP usually responds to glucocorticoids, but some patients may be steroid-refractory or not tolerate standard glucocorticoid doses. For such cases, valid therapeutic alternatives are lacking.1 2 Combinations of prednisone and immunosuppressants (eg, cyclophosphamide, mycophenolate mofetil) are not of proven superiority to prednisone alone, and their effectiveness in refractory CP is unknown.3 4 Because B cells abundantly infiltrate CP lesions,5 and CP is often associated with autoimmune diseases,6 we used rituximab in two patients with CP, one refractory to conventional treatments, and the other with contraindications to standard-dose glucocorticoids. Our first patient, a 49-year-old woman, was hospitalised for malaise and back pain. Abdominal CT revealed a soft-tissue-density periaortic mass suggesting CP, a diagnosis confirmed by laparoscopic biopsy (figure 1). The patient responded to prednisone (initial dose, 1 mg/kg/day), with symptom remission and reduction in CP thickness, but relapsed with back pain and CP enlargement when the prednisone dose was 5 mg/day (8 months after treatment initiation). …

Eosinophilic Granulomatosis with Polyangiitis: An Overview

Eosinophilic granulomatosis with polyangiitis (EGPA) is a multisystemic disorder, belonging to the small vessel anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis, defined as an eosinophil-rich and necrotizing granulomatous inflammation often involving the respiratory tract, and necrotizing vasculitis predominantly affecting small to medium-sized vessels, associated with asthma and eosinophilia. EGPA pathogenesis is not well known: HLA-DRB1*04 and *07, HLA-DRB4 and IL10.2 haplotype of the IL-10 promoter gene are the most studied genetic determinants. Among the acquired pathogenetic factors, the exposure to different allergens, infections, vaccinations, drugs, and silica exposure have been involved. Eosinophils are the most characteristic cells in EGPA and different studies have demonstrated their role as effector and immunoregulatory cells. EGPA is considered as a disease with a prevalent activation of the Th-2 cellular-mediated inflammatory response and also humoral immunity plays an important role. A link between B and T inflammatory responses may explain different disease features. EGPA typically develops into three sequential phases: the allergic phase, distinguished by the occurrence of asthma, allergic rhinitis, and sinusitis, the eosinophilic phase, in which the main pathological finding is the eosinophilic organ infiltrations (e.g., lungs, heart, and gastrointestinal system), and the vasculitic phase, characterized by purpura, peripheral neuropathy, and constitutional symptoms. ANCA (especially pANCA anti-myeloperoxidase) are present in 40–60% of the patients. An elevation of IgG4 is frequently found. Corticosteroids and cyclophosphamide are classically used for remission induction, while azathioprine and methotrexate are the therapeutic options for remission maintenance. B-cell depletion with rituximab has shown promising results for remission induction.

Methotrexate plus prednisone in patients with relapsing idiopathic retroperitoneal fibrosis

Idiopathic retroperitoneal fibrosis (IRF) is a rare disease, characterised by a fibroinflammatory tissue surrounding the aortoiliac axis and frequently entrapping the ureters.1 ,2 Glucocorticoids effectively induce remission, but 24% to 72% of patients relapse, half of them repeatedly.3 ,4 Immunosuppressants and glucocorticoids are usually required in relapsing IRF but no studies are available. In this prospective, open-label trial we enrolled 16 relapsing patients with IRF (July 2004 to April 2011) aged 18–85 years and with an estimated glomerular filtration rate (eGFR)>50 ml/min5 after ureteral decompression (if required), and treated them with methotrexate and prednisone for 12 months. Relapse was defined in case of mass enlargement, hydronephrosis, or disease-related symptoms associated with high inflammatory markers.3 Prednisone was given at 0.5–1 mg/kg/day depending on flare severity, tapered to 12.5–10 mg/day by month 3, 7.5–5 mg/day by month 6 and maintained at 5–2.5 mg/day until month 12. Methotrexate was given at 15–20 mg/week until month 12. After month 12, the clinician was free to continue or withdraw the treatment. The primary endpoint was remission (at month 12) defined as a stable, reduced mass and absence of hydronephrosis, disease-related symptoms and normal inflammatory markers.3 Secondary endpoints were changes in erythrocyte sedimentation …

CC chemokine receptor 5 polymorphism in chronic periaortitis

OBJECTIVE Chronic periaortitis (CP) is a rare disease characterized by a fibro-inflammatory tissue surrounding the abdominal aorta, and includes non-aneurysmal [idiopathic retroperitoneal fibrosis (IRF)] and aneurysmal forms [inflammatory abdominal aortic aneurysm (IAAA)]. We investigated whether CC chemokine receptor 5 (CCR5)Δ32 polymorphism confers susceptibility to CP. METHODS One hundred CP patients and 180 healthy controls were genotyped for CCR5Δ32 polymorphism by molecular methods. The patients were subgrouped according to the type of CP (IRF or IAAA) and the presence of established atherosclerotic disease (ischaemic heart disease, cerebrovascular disease and peripheral arterial disease). RESULTS The distribution of the CCR5Δ32 genotype differed between CP patients and controls (P = 0.01). The CCR5Δ32 allele was more frequent in CP patients than in controls [P = 0.02, odds ratio (OR) 2.8 (95% CI 1.2, 6.4)]. The distribution of the CCR5Δ32 genotype did not differ significantly between IRF patients and controls, whereas the CCR5Δ32 allele was more frequent in IAAA patients than in controls [P = 0.0001, OR 10.0 (95% CI 3.7, 27.3)]. Furthermore, the CCR5Δ32 allele occurred more frequently in IAAA than in IRF patients [P = 0.001, OR 6.4 (95% CI 2.1, 19.1)]. The CCR5Δ32 allele frequency was higher in IAAA patients without established atherosclerotic disease compared with controls [66.7 vs 5.6%, P = 0.00001, OR 34.0 (95% CI 7.4, 156.3)], but not in IAAA patients with atherosclerotic disease and IRF patients with or without atherosclerotic disease. CONCLUSIONS The CCR5Δ32 polymorphism might be associated with an increased risk of developing the aneurysmal form of CP, IAAA, particularly in patients without established atherosclerotic disease. Chemokines may have a role in the pathophysiology of CP.

Chronic periaortitis with thoracic aorta and epiaortic artery involvement: a systemic large vessel vasculitis?

OBJECTIVE Chronic periaortitis (CP) is a rare disease characterized by fibro-inflammatory tissue surrounding the abdominal aorta and the iliac arteries. Anecdotal reports have shown that CP may also involve other vascular districts, particularly the thoracic aorta. The aim of this study was to investigate the thoracic aorta and epiaortic artery involvement in CP. METHODS Patients were eligible if they had undergone imaging studies assessing inflammatory involvement of the thoracic aorta and its major branches (e.g. contrast CT, MRI or PET-CT). We explored the patterns of thoracic vessel involvement and compared the clinical characteristics of patients with and without thoracic disease. Where available, we also reviewed the thoracic vascular/perivascular tissue biopsies. RESULTS Of 153 CP patients seen between 1999 and 2012, 77 were eligible. Of these, 28 (36%) had thoracic involvement: 15 (54%) had thoracic periaortitis, with 7 also showing epiaortic artery involvement; 6 (21%) had periaortitis surrounding a thoracic aortic aneurysm, 2 of them with epiaortic artery involvement; 7 (25%) had a thoracic aortic aneurysm without periaortitis. Patients with thoracic disease were more frequently female (P = 0.01), were older (P = 0.001) and had a higher frequency of pain and constitutional symptoms (P = 0.02). Thoracic (peri)vascular biopsies revealed adventitial and peri-adventitial fibro-inflammatory patterns similar to those observed in abdominal CP. CONCLUSION In about one-third of patients, CP also involves the thoracic aorta and the epiaortic arteries, which supports the hypothesis of a systemic inflammatory disease of the large arteries.

Complement blockade in ANCA-associated vasculitis: an index case, current concepts and future perspectives

Complement alternative pathway (cAP) hyperactivation seems to be involved in ANCA-associated vasculitis (AAV). We here describe a case of AAV with severe activation of cAP that developed acute renal failure. No mutation predisposing to cAP dysregulation was identified. We treated our patient with the standard immunosuppressive therapy, but disease progression was only reversed after the addition of eculizumab, a monoclonal antibody against C5; the patient eventually achieved an almost complete renal function recovery. A review of the available literature about the role of complement targeted therapies in the treatment of AAV is discussed.

Erdheim-Chester Disease as a Mimic of IgG4-Related Disease: A Case Report and a Review of a Single-Center Cohort.

AbstractImmunoglobulin-G4 (IgG4)-related disease (IgG4RD) is a fibro-inflammatory disorder characterized by tissue-infiltrating IgG4+ plasma cells, and, often, high serum IgG4. Several autoimmune, infectious, or proliferative conditions mimic IgG4RD. Erdheim-Chester disease (ECD) is a rare non-Langerhans cell histiocytosis, characterized by foamy histiocytic infiltration, fibrosis, and chronic inflammation. ECD and IgG4RD manifestations may overlap.A patient presented with huge fibrous retroperitoneal masses causing compression on neighboring structures; the case posed the challenge of the differential diagnosis between IgG4RD and ECD mainly because of a prominent serum and tissue IgG4 response.Retroperitoneal biopsy led to the diagnosis of ECD; the V600E BRAF mutation was found. Treatment with the BRAF inhibitor vemurafenib was started.Treatment failed to induce mass regression and the patient died after 3 months of therapy. Prompted by this case, we examined serum and tissue IgG4 in a series of 15 ECD patients evaluated at our center, and found that approximately one-fourth of the cases have increased IgG4 in the serum and often in the tissue.The differential diagnosis between IgG4RD and ECD can be challenging, as some ECD patients have prominent IgG4 responses. This suggests the possibility of common pathogenic mechanisms between ECD and IgG4RD.

Brief Report : Rituximab for the Treatment of Adult-Onset IgA Vasculitis (Henoch-Schönlein)

Adult‐onset IgA vasculitis (Henoch‐Schönlein) (IgAV) is a rare systemic vasculitis characterized by IgA1‐dominant deposits. The treatment of adult‐onset IgAV is controversial and is based on the combination of glucocorticoids and immunosuppressive agents, but many patients have refractory or relapsing disease despite treatment. Rituximab (RTX) is a B cell–depleting antibody of proven efficacy in antineutrophil cytoplasmic antibody–associated vasculitis. We undertook this study to test the efficacy and safety of RTX in a multicenter cohort of patients with adult‐onset IgAV.