Zusammenfassung Der Nachweis von Autoantikörpern ist ein wichtiger Bestandteil der Diagnostik und Verlaufskontrolle von Patienten mit Autoimmunerkrankungen. In der Labordiagnostik der Kollagenosen und der autoimmunen Lebererkrankungen spielt die indirekte Immunfluoreszenz an HEp-2-Zellen im Rahmen einer Stufendiagnostik eine zentrale Rolle. Trotz hoher Qualität der Diagnostik können die Befunde zwischen verschiedenen Labors jedoch wegen fehlender Standardisierung und subjektiver Faktoren zum Teil erheblich differieren. Die vorliegende Arbeit formuliert Empfehlungen für eine vereinheitlichte Bearbeitung und Interpretation des HEp-2-Zell-Testes zum Nachweis von nicht organspezifischen (v.a. antinukleären) Antikörpern. Dabei werden Anforderungen an die verwendeten Diagnostika, Hinweise für die Abarbeitung und Auswertung im Labor und Empfehlungen für die Interpretation gegeben. Für eine optimale Labordiagnostik sind neben einer aussagefähigen klinischen Verdachtsdiagnose und einem erfahrenen Labordiagnostiker folgende Eckpunkte zu empfehlen: Initiales Screening mittels indirekter Immunfluoreszenz an sorgfältig ausgewählten HEp2-Zellen, beginnend mit einer Serumverdünnung von 1:80 und Auswertung in einem lichtstarken Mikroskop, positive Befundung ab einem Titer von 1:160, laborinterne Qualitätssicherung und vereinheitlichte Befundung. Ziel ist die Verbesserung der Diagnostik und Betreuung von Patienten mit Autoimmunerkrankungen als zentrales Anliegen der „European Autoimmunity Standardization Initiative“ (EASI).

Systemic autoimmune diseases are characterized by the presence of antinuclear autoantibodies (ANA). Diluted patient sera are typically used to screen for the presence of ANA by immunfluorescence microscopy with fixed HEp-2 cells. Despite high-quality test kits, reports of different laboratories frequently present controversial results. This article recommends unified processing and interpretation of HEp-2 based screening for autoantibodies. Suggestions are made for the selection of high-quality test kits, optimized processing and diagnostic procedures. In addition to a relevant clinical diagnosis and an experienced laboratory specialist, the following procedure is highly recommended to achieve good laboratory practice: Initial HEp-2 based screening by indirect immunofluorescence, starting with a 1:80 serum dilution, and evaluation in a bright fluorescence microscope, pathological values from a titer of 1:160 upwards, internal quality checks and unified interpretation. We aim to improve diagnosis and care of patients with autoimmune diseases as a central focus of the European Autoimmunity Standardization Initiative (EASI).

Epidermolysis bullosa acquisita (EBA) is a severe immunobullous disease and is caused by IgG against type VII collagen (Col VII) of anchoring fibrils. In this study, utilizing ELISA and immunoblot, 13/15 EBA sera but 0/20 bullous pemphigoid sera and 0/30 healthy control sera showed IgG reactivity with distinct recombinant subregions of the non-collagenous domain 1 (NC1) of Col VII. In two EBA patients, IgG titers against Col VII-NC1 were grossly correlated to clinical disease activity. Moreover, Col VII-reactive T cells were identified in a representative EBA patient which recognized identical subdomains of Col VII-NC1. These findings strongly suggest that (1) the Col VII-NC1 ELISA is a powerful tool for making the diagnosis of EBA, (2) Col VII-specific IgG grossly relates to disease activity and (3) IgG reactivity is associated with T cell recognition of identical subdomains of Col VII-NC1.

The treatment of severe autoimmune skin diseases and of toxic epidermal necrolysis (ICD: L51.2) with high-dose intravenous immunoglobulins (IVIg) is an established therapeutic procedure in dermatology. As IVIg are usually only administered in rare autoimmune diseases or in particularly severe disease courses, use of immunoglobulins in dermatology is commonly not based on experience from controlled and randomized studies typically demanded by evidence-based medicine. In face of the rarity of indications for IVIg it is improbable that such studies will be performed in the foreseeable future. Further, as the high costs of IVIg treatment limits its use as first-line therapy, no clear guidelines exist yet on IVIg use in skin diseases. The present recommendation is based on a consensus of the Working Group on European Guidelines of the EDF (European Dermatology Forum) and the EADV (European Association of Dermato-Venereology) and should provide aid in decision making for the use of IVIg in treating dermatologic diseases

The detection of autoantibodies is an important element in the diagnosis and monitoring of disease progression in patients with autoimmune diseases. In laboratory diagnostic tests for connective tissue and autoimmune liver diseases, indirect immunofluorescence on HEp-2 cells plays a central role in a multistage diagnostic process. Despite the high quality of diagnostics, findings at different laboratories can differ considerably due to a lack of standardization, as well as subjective factors. The present paper formulates recommendations for the standardized processing and interpretation of the HEp-2 cell test for the detection of non-organ-specific (especially antinuclear) antibodies. It provides requirements regarding the diagnostic tests used, instructions for laboratory procedure and evaluation, and recommendations for interpretation. For an optimal laboratory diagnostic process, it is useful to have an informative, tentative clinical diagnosis and an experienced laboratory diagnostician. In addition, the following key elements are recommended: initial screening using indirect immunofluorescence on carefully chosen HEp-2 cells beginning with a serum dilution of 1:80 and evaluation under a microscope with powerful illumination; results from a titer of 1:160 upwards being considered positive; internal laboratory quality control; and standardized interpretation. The aim is to improve diagnostic tests and care of patients with autoimmune diseases as a central concern of the European Autoimmunity Standardization Initiative (EASI).

In this paper, we characterize the novel human leucocyte antigen (HLA)-DPB1*2402 allele that we found in a patient suffering from acne vulgaris. In comparison to the closest related allele DPB1*0401, HLA-DPB1*2402 has a single nucleotide exchange at position 115 (202), T replaces G. In consequence, codon 39 (68) TAC encodes for tyrosine in the novel allele instead of aspartic acid 39 (68) GAC in DPB1*0401.

Background: New techniques for diagnostics and therapy in dermatology are becoming increasingly non‐invasive, among which confocal laser‐scanning microscopy (CLSM) is the most prevalent. It allows visualization of cellular structures of the skin up to a depth of 300 μm in vivo . Until now, most studies have been conducted on pathologically altered skin, mostly oncologic lesions. We now present a detailed analysis of capillaries located in the upper dermal papillae. Methods: Multiple measurements were performed on the dorsal and ventral surface of the right forearm of 30 healthy volunteers (22–88 years) under standard conditions (room temperature, body position, time of day). Images were obtained with the Vivascope 1500 (Lucid) under standard settings and analyzed using the freeware ImageJ with a customwritten macro plugin. The following parameters of the capillaries in vivo were measured: area, perimeter, circularity and maximum diameter. Results: Statistical analysis showed that all four parameters were constant within a narrow range, regardless of the body site, sex and age. In this physiological study, we can clearly demonstrate that by confocal laser‐scanning capillaroscopy (CLSC), it is possible to visualize and measure skin capillaries at the extremities in a reproducible manner. Conclusion: This new approach offers a considerable advantage compared with nailfold capillaroscopy, which can only be performed at the proximal nail segment, and over histological analysis, which can be hampered by fixation artifacts resulting in altered size and shape of the vessels to be analyzed. CLSC could allow for precise analysis of in vivo skin vasculature in systemic and proliferative diseases of the skin.

An increased level of circulating nuclear antigens caused by apoptosis is thought to be responsible for the production of autoantibodies in lupus erythematosus (LE). The presentation of these antigens to immunologically competent cells may trigger systemic autoimmunity. The influence of a functional single-nucleotide polymorphism at position -670 in the promoter of the apoptosis gene FAS on susceptibility to autoimmune diseases including systemic LE has been a controversial subject. Although it has not yet been possible to assign any particular allele or genotype to the control of FAS expression, this polymorphism has been described to be associated with several autoimmune diseases including LE. When we compared the FAS -670 A/G genotypes of 107 German patients with LE and those of 96 healthy controls, we found a trend for association between LE and the homozygous A genotype in the patient group. This finding suggests that apoptosis may contribute to development of autoimmune reactions and that FAS function might be relevant for LE.

Background. Autoimmune bullous disorders of the pemphigus group are characterized by autoantibodies targeting desmoglein (Dsg) 1, Dsg3 and Dsg4 and occasionally, desmocollin (Dsc) 1, Dsc2 and Dsc3. Both Dsg and Dsc are components of desmosomal adhesion complexes.Aim. To investigate the presence of IgG and IgA autoantibodies against Dsc1, Dsc2 and Dsc3 in a cohort of patients with bullous disorders.Methods. IgG and IgA autoantibodies against Dsc1, Dsc2 and Dsc3 were investigated by ELISA and immunoblotting analysis in a cohort of European patients with pemphigus vulgaris (PV; n = 74), IgA pemphigus (n = 3), paraneoplastic pemphigus (PNP; n = 3) and two cases of atypical pemphigus (n = 2).Results. Of the two cases with atypical pemphigus, one showed IgA reactivity against Dsc1 and Dsc3 and weak reactivity against Dsc2, and the other showed both IgG and IgA reactivity against Dsc1. One patient with IgA pemphigus had IgA autoantibodies against Dsc1, Dsc2 and Dsg1, and one patient with PNP had IgG reactivity against with Dsc3. In contrast, all the PV sera showed IgG reactivity against Dsg3 but not against Dsc1-3. Thus, IgG and IgA reactivity against Dsc was restricted to cases of PNP, IgA pemphigus and atypical pemphigus.Conclusions. These findings support the concept that desmocollins are not important autoantigens in PV.

A 22-year-old man with a history of cocaine abuse from 2003 to 2005 developed recurrent bleeding of the nasal septum and a progressive cough and dyspnoea. He was admitted to the intensive care unit because of fulminant pneumonia, impaired renal function and progressive general deterioration. While hospitalized, he developed cutaneous vasculitis, thrombosis of the right subclavian and right jugular veins, testicular pain and, eventually, expanding red papules and plaques on the limbs. The symptoms were a diagnostic challenge, until skin biopsy showed immunoglobulin deposits in small vessels and kidney biopsy focal and segmental pauci-immune, crescentic glomerulonephritis. This led, together with anti-neutrophil cytoplasmic antibodies (cANCA and PR3-ANCA), to the diagnosis of Wegener granulomatosis. The number of affected organ systems in our patient exceeds that commonly found in the literature. Several clinical observations of cocaine abuse followed by Wegener granulomatosis suggest an active induction of a PR3-ANCA-positive vasculitis by cocaine.

Bullous pemphigoid (BP) is mediated by autoantibodies directed against molecules of the basement membrane zone. The biological function of antibodies involves binding to Fc-receptors expressed on human leucocytes. Recent studies suggested that a functional single-nucleotide-polymorphism of the Fcgamma-receptor IIIa (FcgammaRIIIa = CD16) at nucleotide 559 might predispose to the development of antibody-associated autoimmune disorders. This allelic difference affects the level of receptor affinity by predicting either a phenylalanine (F 158, low-affinity) or valine (V 158, high-affinity). We investigated if inherited frequencies of the high- and low-affinity FcgammaRIIIa polymorphism differed between patients with BP and healthy subjects. Genomic DNA from peripheral white blood cells was analyzed regarding FcgammaRIIIa polymorphism at nucleotide 559 by an established polymerase chain reaction. Sixty-seven Caucasian patients with BP and 88 healthy controls were included into the study. There was no significant difference in the distribution of the homozygous high-affinity FcgammaRIIIa-allotype (V/V) between BP-patients (14.9%) and healthy control subjects (20.5%). In contrast, 58.2% of the BP-patients were homozygous for the low-affinity FcgammaRIIIa-allotype (F/F), compared to 28.4% of the healthy controls (P = 0.001, OR 3.51). The frequencies of the polymorphism in the control group were in range of formerly published frequencies for healthy Caucasian subjects. Thus, the FcgammaRIIIa (158 F/V) polymorphism may modulate the susceptibility to acquire BP.