Hajime Yamagata

Patients With Pulmonary Tuberculosis Are Frequently Positive for Anti–Cyclic Citrullinated Peptide Antibodies, but Their Sera Also React With Unmodified Arginine-Containing Peptide

OBJECTIVE The anti-cyclic citrullinated peptide (anti-CCP) enzyme-linked immunosorbent assay (ELISA) has high sensitivity and specificity for rheumatoid arthritis (RA). However, detection of anti-CCP in patients with active pulmonary tuberculosis (TB) has recently been reported. To determine whether this activity was specific for the citrullinated residue, the specificity of anti-CCP-positive sera for CCP versus that for unmodified arginine-containing peptide (CAP) was examined in patients with TB and compared with that in patients with RA. METHODS Anti-CCP and anti-CAP in sera from patients with pulmonary TB (n = 49), RA patients (n = 36), and controls (n = 18) were tested by ELISA. Sera were available at diagnosis from most TB patients. All TB patients were treated with a combination of 2-4 antibiotics for at least 6 months, and sera were collected over time. RESULTS Anti-CCP was found in 37% of TB patients and in 43% of RA patients. CAP reactivity was more common in TB than in RA. High anti-CCP:anti-CAP ratios (>2.0) were seen far more commonly in anti-CCP-positive RA patients than in anti-CCP-positive TB patients (94% versus 22%). Anti-CCP was inhibited by CCP peptide in sera from RA patients, but not in sera from TB patients. A slight increase in anti-CCP was common after initiating treatment for TB, although the anti-CCP level decreased after 1-2 months. CONCLUSION Anti-CCP is frequently present in patients with active TB. However, many anti-CCP-positive TB sera also reacted with CAP, and anti-CCP:anti-CAP ratios in TB sera were low. Anti-CCP:anti-CAP ratios should be useful clinically for distinguishing CCP-specific reactivity seen in RA from reactivity with both CCP and CAP frequently seen in pulmonary TB.

Development of anti-Sm and anti-DNA antibodies followed by clinical manifestation of systemic lupus erythematosus in an elderly woman with long-standing Sjögren's syndrome

A 69-year-old Japanese women who had been followed up for 10 years as a primary Sjögrens syndrome, is reported. She suddenly developed serological and clinical characteristics of systemic lupus erythematosus (SLE): anti-Sm and anti-dsDNA antibodies followed by nephrotic syndrome and pancytopenia. This case suggests that the diagnosis of primary Sjögrens syndrome should be considered as tentative in certain cases and that the development of serological characteristics precede and are associated with the development of clinical symptoms of SLE.

Late development of anti-La/SS-B antibodies in a patient with Sjogren's syndrome and high titer anti-Ro/SS-A antibodies

The frequent coexistence of anti-Ro and anti-La autoantibodies is well described, however, there is little evidence of sequential development of these two autoantibodies. We report a case of typical Sjogrens syndrome with high titer anti-Ro antibodies, who subsequently developed anti-La antibodies later in the course. This case suggests that the anti-La anti bodies may actually follow the anti-Ro antibodies in some cases as hypothesized in the concept of linked set of autoantibodies, analogous to development of anti-Sm in certain anti-nRNP antibody positive SLE patients and animal models.

Restricted heterogeneity and changing spectrotypes in autoantibodies to La/SS-B.

Isoelectric focusing (IEF) spectrotype of specific immunoglobulins has been studied as a marker for B-cell clonality. In the present study, the spectrotype of anti-La antibodies in human autoimmune sera were analyzed by newly developed IEF sandwich assay in which focused total immunoglobulin on filter papers are incubated with crude antigen followed by horse-radish peroxidase-labeled anti-La antibodies. The anti-La spectrotypes contained oligoclonal bands, the positions and patterns of which are different in each patient, suggesting the preferential expansion of limited numbers of anti-La producing B-cell clones unique to individual patients. Furthermore, the bands on anti-La spectrotype in sequentially obtained sera changed continuously, suggesting alteration in the expanding anti-La producing clones. These may reflect affinity maturation and/or diversification of the B-cell epitopes involving somatic mutation.

NEFA/nucleobindin-2 is a target autoantigen of the anti-Wa antibody and is associated with transfer RNA.

ObjectivesThe anti-Wa antibody found in systemic sclerosis patients reacts with a transfer RNA (tRNA)-associated 48-kDa protein and immunoprecipitates several tRNAs. We investigated the Wa antigen and its binding to tRNA species.MethodsWe performed molecular cloning of the Wa antigen and made its recombinant protein. To investigate Wa antigen distribution in the cell, we performed an indirect immunofluorescence study. To determine the Wa-bound tRNA species, we performed a reverse transcription (RT)-polymerase chain reaction (PCR) using the RNAs immunoprecipitated by anti-Wa antibody as templates, and synthetic primers of mammalian tRNA sequences. To clarify the tissue expression of Wa antigen, we performed quantitative and semi-quantitative PCR of the cDNA.ResultsWe demonstrated that the Wa antigen was identical to NEFA (DNA binding/EF-hand/acidic amino acid rich region), otherwise known as nucleobindin-2. A full-length and an alternative splice variant cDNA lacking exon 11 were isolated by cloning NEFA cDNA. Anti-Wa-positive sera stained both the nucleus and cytoplasm of HEp-2 cells. RT-PCR suggested that Wa binds at least six tRNA species. In human tissues, NEFA is expressed predominantly in exocrine glands.ConclusionsWe have demonstrated that the Wa antigen is NEFA or nucleobindin-2, which binds specific tRNA species, and is distributed in specific human tissues.

Marked thrombocytosis with chromosomal abnormalities in a patient with rheumatoid arthritis.

SummaryAn 80 year-old Japanese woman with rheumatoid arthritis (RA), complicated with thrombocytosis is described. Mild to moderate thrombocytosis is commonly observed in patients with RA, but she had marked thrombocytosis of over 1000 × 103/mm3 and monosomy 22 with marker chromosome. This case suggests that thrombocytosis unusual with disease activity of RA might occur, and that careful evaluation of the thrombocytosis is required.

Chronic destructive monoarthritis of the wrist in patients with anti-SSA/Ro antibodies: report of two cases.

SummaryAmong 340 patients with rheumatic diseases, two cases of chronic destructive monoarthritis of the wrist with anti-SSA/Ro antibodies and rheumatoid factor, were observed for over three years. It is not clear whether these cases represent a specific subset of rheumatoid arthritis (RA) or whether they may progress to diffuse symmetrical destructive polyarthritis typical of RA. Long-term follow-up studies including analysis of autoantibodies will be needed to clarify the characteristics and course of chronic monoarthritis.