Patients diagnosed with juvenile-onset systemic lupus erythematosus (JSLE) often have skin and oral lesions as part of their presentation. These mucocutaneous lesions, as defined by the American College of Rheumatology (ACR) in 1997, include malar rash, discoid rash, photosensitivity and oral ulcers. It is therefore essential to recognize mucocutaneous lesions to accurately diagnose JSLE. The mucocutaneous lesions can be divided into those with classical histological features (LE specific) and those strongly associated with and forming part of the diagnostic spectrum, but without the classical histological changes of lupus (LE nonspecific). A malar rash is the most commonly associated LE specific dermatological presentation. This skin manifestation is an acute form and also correlates with disease activity. Subacute (polycyclic or papulosquamous lesions) and chronic (discoid lesions) forms, whilst showing classical histological changes supportive of lupus, are less commonly associated with systemic lupus and do not correlate with disease activity. The most commonly associated skin lesions without classical lupus changes are cutaneous vasculitis, oral ulcers and diffuse non-scarring alopecia. These signs frequently relate to disease activity. An understanding of cutaneous signs and symptoms of lupus in children is important to avoid delay in diagnosis. They will often improve as lupus is adequately controlled and their reappearance is often the first indicator of a disease flare.

Anti-neutrophil cytoplasmic antibodies (ANCA) are a group of autoantibodies that cause systemic vascular inflammation by binding to target antigens of neutrophils. These autoantibodies can be found in serum from patients with systemic small-vessel vasculitis and they are considered as a biomarker for ANCA-associated vasculitis (AAV). A conventional screening test to detect ANCA in the serum is indirect immunofluorescence study, and subsequently confirmed by enzyme-linked immunosorbent assay. A positive staining of ANCA can be classified into three main categories based on the staining patterns: cytoplasmic, perinuclear, and atypical. Patients with granulomatosis with polyangiitis (GPA) mostly have a positive cytoplasmic staining pattern (c-ANCA) whilst a perinuclear pattern (p-ANCA) is more common in microscopic polyangiitis (MPA) and eosinophilic granulomatosis with polyangiitis (EGPA) patients. Atypical pattern (a-ANCA) is rarely seen in patients with systemic small-vessel vasculitis but it can be found in other conditions. Here, techniques for ANCA detection, ANCA staining patterns and their clinical significances are reviewed.

Introduction The translocation of organismal molecules from gut into blood circulation might worsen the disease severity of lupus through the induction of neutrophil extracellular traps (NETs). Methods An impact of lipopolysaccharide (LPS) and (1→3)-β-D-glucan (BG), components of gut bacteria and fungi, respectively, on NETs formation, was explored in lupus models, Fc gamma receptor IIB deficiency (FcGRIIB-/-) and Pristane injection, using Candida- administered dextran sulfate solution induced colitis ( Candida -DSS) model. Results Severity of Candida -DSS in FcGRIIB-/- mice was more prominent than wild-type (WT) and Pristane mice as indicated by (i) colonic NETs using immunofluorescence of Ly6G, myeloperoxidase (MPO) and neutrophil elastase (NE) together with expression of PAD4 and IL-1β , (ii) colonic immunoglobulin (Ig) deposition (immunofluorescence), (iii) gut-leakage by FITC-dextran assay, endotoxemia and serum BG, (iv) systemic inflammation (neutrophilia, serum cytokines, serum dsDNA and anti-dsDNA) and (v) renal injury (proteinuria, glomerular NETs and Ig deposition). Discussion The formation of NETs in Candida -DSS mice was more severe than non- Candida -DSS mice and NETs in Candida -DSS were more profound in FcGRIIB-/- mice than Pristane mice. Prominent NETs in Candida -DSS FcGRIIB-/- mice might be due to the profound responses against LPS+BG in FcGRIIB-/- neutrophils compared with WT cells. These data implied an impact of the inhibitory FcGRIIB in NETs formation and an influence of gut fungi in lupus exacerbation. Hence, gut fungi in a DSS-induced gut-leakage lupus model enhanced colonic NETs that facilitated gut translocation of organismal molecules and synergistically exacerbated lupus activity.