Anti-cyclic citrullinated peptide antibody isotypes in rheumatoid arthritis: association with disease duration, rheumatoid factor production and the presence of shared epitope.

OBJECTIVE: Anti-cyclic citrullinated peptide (anti-CCP) antibodies of IgG isotype are specific diagnostic markers of rheumatoid arthritis (RA). Recent evidence also points to their direct involvement in the pathophysiology. Little information is available, however, regarding the isotype distribution of anti-CCP antibodies and the characteristics of IgA and IgM anti-CCP. METHODS: IgG, IgA and IgM anti-CCP2 and rheumatoid factor (RF) levels were measured in the sera of 119 RA patients and 118 controls, including patients with other rheumatic diseases and healthy subjects. We analyzed the diagnostic performance of IgA and IgM anti-CCP2 antibodies and their relationship with IgG anti-CCP2, RFs, disease duration and the presence of HLA-DRB1 shared epitope (SE) alleles. RESULTS: Patients with RA had significantly higher serum IgA and IgM anti-CCP2 antibody levels than healthy subjects and patients with other rheumatic diseases (p<0.0001). IgG, IgA and IgM anti-CCP2 antibodies were present in 74.8%, 52.9% and 44.5% of RA patients, and their diagnostic specificity was 95.8%, 95.8% and 91.6%, respectively. The presence of anti-CCP2 antibodies was significantly associated with SE alleles (p=0.03). The frequency of IgM anti-CCP2 positivity was lower in longstanding disease compared to early RA (p=0.03). CONCLUSION: IgA and IgM anti-CCP2 antibodies are present in RA patients, and they are similarly specific for RA as IgG anti-CCP2. The higher frequency of IgM anti-CCP2 antibodies in early RA suggests that they are mostly generated during the first phase of immune response; nonetheless, their production seems to be sustained in some patients. Further analysis of IgM and IgA anti-CCP2 antibodies may provide insights into the pathogenesis of RA.

Distribution of nitric oxide synthase containing elements in the feline submandibular gland.

Combined nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry and nitric oxide synthase (NOS) immunocytochemistry were used to study the distribution of nitric oxide synthesizing elements in the cat submandibular gland. A large number of thin varicose fibres, with intense staining for both markers, were seen around or in close contact with the acini. Some of the stained nerve fibres were associated with intra- and interlobular salivary ducts and blood vessels. All neurones in the submandibular ganglia showed intense staining for both NADPH-d and NOS. The epithelial layer of the salivary ductal branches and the endothelial lining of blood vessels were NOS immunonegative but NADPH-d positive. Our results suggest that NO might act as a neurotransmitter in the regulation of blood flow and secretion in the submandibular salivary gland.

Detection of Pseudomonas aeruginosa in water samples using a novel synthetic medium and impedimetric technology.

AIMS: To investigate whether the use of a novel synthetic medium in conjunction with impedimetric technology could provide a rapid and automated detection of Pseudomonas aeruginosa in water samples. METHODS AND RESULTS: A selective synthetic medium (Z-broth) in which the only carbon and nitrogen source is acetamide was applied in direct impedimetric examination for the selective isolation of P. aeruginosa. A total of 1036 tap-water, well-water, swimming-pool water and dialysis water samples were investigated, and any P. aeruginosa contamination was detected in 7-24 h. Neither false-negative nor false-positive results were observed. CONCLUSIONS: The results of the present evaluation demonstrate that impedance measurement with the use of Z-broth is suitable for the rapid and automatic detection of P. aeruginosa in water. SIGNIFICANCE AND IMPACT OF THE STUDY: The main advantages of the method: 240 samples can be examined in one step, the procedure is fully automated, the results are obtained quickly and the labour and media requirements are low.