phalloidine and Autoimmune-Diseases

Intracochlear infusion of the KHRI-3 monoclonal antibody results in in vivo binding to guinea pig inner ear supporting cells, loss of hair cells and hearing loss. To further characterize the basis for KHRI-3-induced hearing loss, antibody was produced in a bioreactor in serum-free medium, affinity purified, and compared to conventionally prepared antibody by infusion into the scala tympani using mini-osmotic pumps. In vivo antibody binding was observed in 10 of 11 guinea pigs. A previously unreported pattern of KHRI-3 antibody binding to cells involved in scar formation was noted in five guinea pigs. All but one of the KHRI-3-infused animals demonstrated a hearing loss of > 10 dB in the treated ear. In five of 11 animals the threshold shift was 30 dB or more, and all had hair cell losses. In one guinea pig infused with 2 mg/ml of antibody, the organ of Corti was absent in the basal turn of the infused ear. This ear had a 45-50 dB threshold shift but, curiously, no detectable antibody binding in the residual organ of Corti. Organ of Corti tissue was fragile in antibody-infused ears. Breaks within the outer hair cell region occurred in 5/11 infused ears. The contralateral ears were normal except for one noise-exposed animal that demonstrated hair cell loss in the uninfused ear. Three animals were exposed to 6 kHz noise (108 dB) for 30 min on day 7. Antibody access to the organ of Corti may be increased in animals exposed to noise, since the strongest in vivo binding was observed in noise-exposed animals. Loss of integrity of the organ of Corti seems to be the primary mechanism of inner ear damage by KHRI-3 antibody. The binding of KHRI-3 antibody in new scars suggests a role of the antigen in scar formation. Antibodies with binding properties similar to KHRI-3 have been detected in 51% of patients diagnosed with autoimmune sensorineural hearing loss; thus, it seems likely that such autoantibodies also may have pathologic effects resulting in hearing loss in humans.

Topics: Animals; Antibodies, Monoclonal; Autoimmune Diseases; Cicatrix; Ear, Inner; Guinea Pigs; Hair Cells, Auditory; Hearing Loss, Sensorineural; Hearing Loss, Sudden; Humans; Mice; Microscopy, Fluorescence; Organ of Corti; Phalloidine

Antibodies to nuclei (ANA), smooth muscle (SMA), and liver/kidney microsomes type 1 (anti-LKM1) may occur in chronic hepatitis C. Distinct subspecificities, including ANA with the homogeneous pattern (ANA-H) and SMA with antiactin specificity (SMA-AA), are found in autoimmune hepatitis (AIH). This study was performed to characterize the hepatitis C virus (HCV)-associated autoantibodies and to evaluate their influence on the profile of the disease. Two hundred ninety consecutive patients with chronic hepatitis C and 35 control cases with AIH were screened for autoantibodies by indirect immunofluorescence (IFL) at 1:40 serum dilution. The ANA pattern was defined by IFL on HEp-2 cells and the SMA-AA identified by the presence of at least two of the following elements: 1) SMA(T) or SMA(G) pattern by IFL on kidney sections; 2) XR1 precipitating system by counterimmunoelectrophoresis; or 3) typical pattern by IFL on liver sections from phalloidin-intoxicated rats. ANA, SMA, and anti-LKM1 occurred in 9%, 20%, and 6% of chronic hepatitis C cases, respectively. The overall prevalence of autoantibodies was 30% (87 of 290). Compared with AIH, HCV-associated ANA and SMA exhibited ANA-H and SMA-AA at a lower prevalence (38% vs. 71%, P = .04 and 8% vs. 87%, P < .000001, respectively) and had a lower median titer (1:80 vs. 1:320, P < .001 and 1:40 vs. 1:320, P < .000001, respectively). The concomitant positivity for ANA-H and SMA-AA was detected in none of the HCV cases, but in 46% of AIH sera (P < .000001). Two parameters were independently associated with the autoantibodies in chronic hepatitis C: high alanine transaminase (ALT) serum levels (F = 14.04) and female gender (F = 5.03). At the univariate analysis, patients with autoantibodies had a more severe portal-periportal necroinflammation (median Scheuer's score: 2.05 vs. 1.64, P = .003). The presence of autoantibodies did not influence the response to interferon (IFN). In chronic hepatitis C, serum autoantibodies are common, but their subspecificities are distinct from those occurring in AIH. Whereas the absence of ANA-H and/or SMA-AA does not exclude AIH, the characterization of ANA and SMA may help to discriminate between the two conditions. As compared with the seronegative counterpart, autoantibody-positive chronic hepatitis C is more common in females and exhibits a more severe biochemical and histological activity. The response to IFN therapy, however, is similar.

Topics: Analysis of Variance; Animals; Antibodies, Antinuclear; Autoantibodies; Autoimmune Diseases; Female; Fluorescent Antibody Technique, Indirect; Hepacivirus; Hepatitis; Hepatitis C; Humans; Liver; Liver Function Tests; Mice; Microsomes; Middle Aged; Muscle, Smooth; Phalloidine; Rats

Smooth muscle antibodies with anti-actin specificity are commonly regarded as markers of autoimmune liver disease. However, there are interpretational problems because different techniques have been used for their identification and therefore the results are difficult to compare. The present paper reports the results of a new method for the identification of anti-actin antibodies (indirect immunofluorescence on cryostat sections of liver from rats chronically injected with phalloidin). The results have been compared with those obtained by four other techniques: demonstration by immunofluorescence of kidney peritubular reactivity (SMAT), of anti-microfilament antibodies (on HEp-2 cells and vinblastine-treated peripheral blood mononuclear cells) and counterimmunoelectrophoresis with purified muscle actin as antigen. The new method proved to be the most sensitive and specific. Furthermore, its reproducibility was found to be high, the interpretation easy and the cost low. The clinical significance of anti-actin antibodies in patients with chronic liver disease is also discussed.

Topics: Actins; Autoantibodies; Autoimmune Diseases; Cells, Cultured; Chronic Disease; Fluorescent Antibody Technique; Humans; Immunologic Techniques; Liver; Liver Diseases; Muscle, Smooth; Phalloidine

Topics: Adult; Autoimmune Diseases; Cholelithiasis; Cholestasis; Cholestasis, Extrahepatic; Ethanol; Female; Gallbladder Neoplasms; Hepatitis; Humans; Hydrocarbons, Halogenated; Phalloidine