[Autoantibody diagnostics in neurology using native and recombinant antigenic substrates]. / Autoantikörperdiagnostik in der Neurologie mittels nativer und rekombinanter Antigensubstrate.

Modern diagnostics for the determination of neurologically relevant autoantibodies are based on indirect immunofluorescence using tissue sections of the hippocampus, cerebellum and other tissues. For monospecific detection human embryonic kidney (HEK) cells transfected with different neurological antigens are used. Biochip mosaics are designed to give a quick overview and contain 20 or more substances positioned next to each other on a reaction field, which are incubated with the serum or cerebrospinal fluid (CSF) sample. Western blots based on cerebellum or hippocampus extracts or line blots containing defined recombinant antigens are used additionally. Initial investigations should always comprise the parallel analysis of all major antineural autoantibodies instead of performing only single parameter tests. Up until a few years ago autoantibodies against intracellular neuronal antigens were mainly investigated. Antibodies against structures of the neural cell surface, however, are much more frequently found, especially those against glutamate receptors (type NMDA).

Epitope mapping of BP230 leading to a novel enzyme-linked immunosorbent assay for autoantibodies in bullous pemphigoid.

BACKGROUND: Bullous pemphigoid (BP) is an autoimmune subepidermal blistering disease characterized by circulating autoantibodies against BP180 and BP230. For BP180, the NC16A domain has previously been identified as the main antigenic target in BP, while data about the diagnostic value of epitopes on BP230 were inconclusive. OBJECTIVES: To identify the most appropriate epitopes on BP230 to be applied in a simple, sensitive, and highly specific enzyme-linked immunosorbent assay (ELISA) for routine detection of serum autoantibodies. METHODS: Ten overlapping linear fragments covering the whole length of BP230 were expressed in Escherichia coli. Based on Western blot analysis with sera from patients with BP (n = 49) and healthy controls (n = 94), the diagnostic performance of the fragments was compared by receiver operating characteristics curve analysis. The BP230-C3 fragment comprising the C-terminal portion (amino acids 2326-2649) was subsequently applied in a novel ELISA. The operating characteristics of this ELISA were analysed by probing sera from patients with BP (n = 118), pemphigus vulgaris (n = 50), rheumatoid arthritis and other inflammatory arthritides (n = 170), and systemic lupus erythematosus (n = 56), and from healthy blood donors (n = 483). RESULTS: Among all the fragments, BP230-C3 provided the best efficiency in serologically diagnosing BP by Western blot. An ELISA employing BP230-C3 revealed a diagnostic sensitivity of 56·8% and specificity of 97·6%. Its diagnostic added value amounted to 4·2% compared with the anti-BP180-NC16A-4X ELISA alone. CONCLUSIONS: Recombinant BP230-C3 is a suitable target antigen for the detection of serum autoantibodies against BP230.

Seroprevalence of herpes simplex virus type 1 and type 2 in Thuringia, Germany, 1999 to 2006.

The prevalence of herpes simplex virus (HSV) type-specific IgG was determined in sera taken in 1999 to 2006 from 1,100 children aged 0­18 years, 800 blood donors and 200 pregnant women in Thuringia, Germany, using tests based on the HSV glycoproteins (g) gG. By the age of 10­12 years, HSV-1 IgG prevalence reached 57.3%, rising to 69.3% by the age of 16­18 years and to 78.0% by the age of 28­30 years. Between 2.7% and 4.7% of the children aged up to 15 years had HSV-2 antibodies, increasing to 7.3% at the age of 16­18 years and to 13.6% among adults. The prevalence of HSV-1 antibodies among girls was significantly lower than among boys and a significantly higher prevalence of HSV-2 IgG in women than in men was detected. The reduced incidence of HSV-1 infections during childhood, especially in girls, has to be followed up since a higher number of primary HSV-2 infections may result. Between 2.7% and 4.7% of all children tested seemed to acquire HSV-2 by intrauterine or neonatal infection. We also compared the use of gG-1 with gC-1: the agreement of 97.2% between the two ELISAs suggests that gG-1 and gC-1 can be considered equivalent antigenic targets.