Fluorescence patterns of cytoplasmic autoantigens There are many important organelles in the cytoplasm which fulfill various functions of the cell as described in section 1. Various autoantibodies, known as anti-cytoplasmic antibodies, targeting the proteins organizing these organelles and many cytosol proteins have been found. Anti-mitochondrial antibody photo 44 photo 45 Staining of AMA-M2 using rodent kidney and stomach sections as substrates. Cytoplasmic staining in the renal tubular cells (intense staining in the distal tubular cells) and intense fluoresence in the parietal cells of the stomach are observed. Coarse granular filamentous staining extending throughout the cytoplasm. Anti-mitochondrial antibodies-m2 (AMA-M2): pyruvate dehydrogenase (PDH-E2), located on the inner mitochondrial membrane. Antibodies to AMA-M1 and sub-patterns of AMA-M3 to M9 were reported. The staining shown here is due to AMA-M2 antibodies. IF (rodent kidney or stomach sections used as substrates), ELISA, WB, CLEIA These antibodies occur frequently in patients with PBC and their presence constitutes one of the diagnostic criteria of the disease. Recently, the presence of mitochondrial autoantigen in bile was reported. References 53, 54 27
Anti-ribosomal antibody photo 46 photo 47 Staining of anti-ribosomal antibody using rodent kidney and stomach sections as substrates. The diffuse staining in the kidney tubular cells and fluorescence of the chief cells of the stomach are observed. (Comparatively, anti-mitochondrial antibodies fluoresce in the pariental cells of the stomach.) Homogeneous cytoplasmic staining with perinuclear accentuation is associated with nucleolar staining. 3 phosphoproteins of 60S ribosomal particles (P0(38kD), P1(19kD), and P2(17kD)), 28S ribosomal RNA, L12 protein IF, DID, WB, Immunoprecipitation These antibodies occur in patients with SLE associated with neuropsychiatric symptoms. Presence in scleroderma patients was also reported. References 55, 56, 57 28
Anti-Jo-1 antibody photo 48 AF/CDC-10* Fine granular speckled cytoplasmic staining, but weak fluorescence is usual. The granules are condensed around the nucleus and diminish toward the periphery of the cell. The reference serum of AF/CDC-10 from CDC rarely stains in the usual dilution of the test. It was reported that Jo-1 antigens exist in both nucleus and cytoplasm. Histidyl-tRNA-synthetase (catalyzing the binding reaction of histidine to 3'-OH of trnahis) DID, ELISA, Immunoprecipitation, CLEIA These antibodies occur specifically in patients with PM/DM, and is frequently associated with interstitial pulmonary fibrosis and polyarthritis. The presence of these antibodies consititutes one of diagnostic criteria for PM/DM. References 2, 58 Antibodies to other aminoacyl-trna-synthetases (described below) showing similar staining patterns to anti-jo-1 antibody are found in patients with polymyositis and dermatomyositis. [Reference: 59,74, 75] Anti-PL-7 antibody threonyl-trna synthetase Anti-PL-12 antibody alanyl-trna synthetase Anti-OJ antibody isoleucyl-trna synthetase Anti-EJ antibody glycyl-trna synthetase Anti-KS antibody asparaginyl-trna synthetase Antibodies to the signal recognition particle (SRP) show fine dense speckled cytoplasmic staining, and is highly specific to polymyositis. The targeting 54kD protein of SRP bind to the rough endoplasmic reticulum and ribosomes. In patients with these antibodies, poor response to therapy and frequent recurrence are characteristically observed.[reference: 60] * Reference serum from Centers for Disease Control 29
Anti-lysosomal antibody Large speckles distributed throughout the cytoplasm fluorescence. Lysosomal proteins. The enzymes in lysosomes like cathepsin and lysosomeassociated membrane proteins (LAMPs) are considered as candidate antigens. However, they are poorly characterized. These antibodies occur infrequently in patients with SLE. Clear clinical associations are not known. photo 49 References 1, 2 Anti-Golgi apparatus antibody Irregular discontinuous granular staining in cytoplasm around the nucleus. 230kD protein of Golgi apparatus. Recently 97kD (golgin-97) and 200kD non-myosin proteins were reported. These antibodies occur infrequently in patients with SLE and SS. The Golgin-97 was reported to be specific to secondary SS. photo 50 References 61, 62 30
autoantibodies recognizing the protein components of various organelles in cytoplasm The photos shown below suggest the presence of autoantibodies recognizing the protein components of various organelles in cytoplasm, the enzymes in vesicles and secretory granules or degraded substances taken into the vesicles. They show denseto-coarse cytoplasmic staining, but the corresponding antigens are not determined. Photo 54 shows the pattern relevant to cell cycle. photo 51 Dense staining throughout cytoplasm. photo 52 Same as photo 51, but more coarse staining. photo 53 Similar staining to the mitochondrial antibodies but the speckles are different. photo 54 Some of the cell populations show cytoplasmic staining. 31