Noriyuki Kitami

Detection of IgA, IgM, and IgG subclasses of anti-M2 antibody by immunoblotting in autoimmune cholangitis: is autoimmune cholangitis an early stage of primary biliary cirrhosis?

Abstract: Autoimmune cholangitis (AIC) has been proposed as a distinct disease entity from primary biliary cirrhosis (PBC), without antimitochondrial antibody (AMA) and anti-M2 antibody but with a high titer of antinuclear antibody (ANA) in the serum. However, negativity for AMA and anti-M2 antibody was determined by different methods in different studies. We hypothesized that anti-M2 antibody negativity in AIC resulted from methodological differences, including selection of the immunoglobulin subclass of the autoantibody. Twenty-three patients compatible with AIC whose serum tested negative for AMA and positive for ANA (≧1 : 80) were compared with 71 AMA-positive PBC patients. Laboratory findings, histology, and the pattern of anti-M2 antibody assessed by immunoblotting were compared. Alkaline phosphatase, total bilirubin, total cholesterol, and IgM values were lower in patients with AIC (P < 0.05, 0.01, respectively). Anti-smooth muscle antibody was detected more frequently in patients with AIC (P < 0.01). However, anti-M2 antibody was detected using immunoblotting not only in PBC but also in AIC cases. IgA class alone, IgM class alone, or both IgA and IgM classes of anti-M2 antibody were detected in 13%, 17%, and 22% of AIC patients, respectively, whereas they were not detected in PBC patients (P < 0.05, P < 0.01, P < 0.01). IgG class anti-M2 was detected in all patients with PBC, whereas it was detected in 48% of patients with AIC (P < 0.01). Histological evaluation showed that the early stages of disease were found more frequently in AIC (78%) than in PBC patients (39%) (P < 0.01). Anti-M2 antibody was detected by immunoblotting in all AIC patients. Hence, AIC is not a distinct disease from PBC. For diagnosing AIC and/or PBC, anti-M2 antibody should be examined by the immunoblotting assay to detect not only IgG but also IgA and IgM subclasses.

Immunoreactivity to M2 proteins in antimitochondrial antibody-negative patients with primary biliary cirrhosis.

Abstract Although antimitochondrial auto‐antibodies are characteristically present in the serum of patients with primary biliary cirrhosis (PBC), there is a discrepancy between the positivity for antimitochondrial antibody (AMA) and that for anti‐M2 auto‐antibody. In an attempt to explain the discrepancy, this study investigates the relationship between the AMA titre, determined by indirect immunofluorescence, and immunoreactivity to four inner mitochondrial membrance proteins (M2 proteins) with molecular weights of 70, 50, 47, and 40 kDa in 129 patients with PBC. Antimitochondrial antibody positivity was identified in 114 (88%) of 129 patients with clinically and histologically confirmed PBC. There were no significant differences between the AMA‐negative and AMA‐positive groups in clinical characteristics or histologically determined disease stage. Immunoblot analysis showed that all patients had anti‐M2 auto‐antibodies to one or more of the four M2 proteins. Nine (60%) of the 15 AMA‐negative patients had antibodies to only one M2 protein (either 70 or 47 kDa). In contrast, 34 (53%) of the 64 patients with high AMA titres ( 1: 320) had antibodies to all four M2 proteins. There was a significant rank correlation between the AMA titre and the number of antibodies to M2 proteins (P < 0.01). These findings indicate that the AMA titre is not influenced by the immunogenicity of M2 protein but by the number of M2 proteins that elicit an antibody response and that decreased immunoreactivity to M2 proteins may induce AMA negativity in PBC serum samples.

Effect of nicotine in migration and proliferation of rabbit gastric mucosal cells in a culture cell model

Abstract The aim of this study was to assess the effects of nicotine on the gastric epithelial restoration using primary cultured rabbit gastric mucosal cell model.

Pertussis toxin-induced redistribution of cortical actomyosin and inhibition of phagocytosis in rat Kupffer cells

The mechanism of phagocytosis by Kupffer cells has been shown to be related to the Ca2+ ‐calmodulin and the actomyosin systems. However the role of the transmembrane signal transmitter, G‐protein, is still unknown. In this study, a quantitative evaluation of phagocytosis by Kupffer cells of rats in culture and the effects of pertussis toxin, a G‐protein inhibitor, on the phagocytic function and morphology of Kupffer cells were investigated. Pertussis toxin inhibited phagocytosis of Kupffer cells with dysfunction of the actomyosin system. The inhibitory effects of pertussis toxin suggest that G‐protein may be involved in the mechanism of transmembrane signalling in phagocytosis by Kupffer cells.

Marked retention of indocyanine green and sulfobromophthalein with chronic persistent hepatitis.

A hepatitis B virus (HBV) carrier with marked retention of indocyanine green (ICG) and sulfobromophthalein (BSP) was admitted to our hospital for assessment of liver function. On admission, he was asymptomatic and blood chemistry tests showed normal values for transaminases and bilirubin. Serum hepatitis B surface antigen (HBsAg) and antibody to hepatitis B e antigen (anti‐HBe) were positive. A history of drug abuse or alcoholism was denied. Dye excretion tests revealed marked retention of ICG (R15= 70%) and BSP (R45= 23%). Histopathological examination of a liver biopsy specimen obtained during laparoscopic observation showed chronic persistent hepatitis (CPH). Familial research of the patient failed to prove the existence of dye excretory defect in his siblings. Usual cases of CPH due to continuous HBV infection do not show such severe disturbance of organic anion transport.

Extensive hepatic cell necrosis produced by a lymphokine and its partial characterization.

ラット肝細胞ホモジェネートを抗原として家兎を免疫し,感作されたリンパ球を同じ抗原で刺激し,培養後の上清を家兎の腹腔内あるいは門脈内に投与すると,巣状あるいは亜広範性肝壊死が惹起され,肝壊死の程度は使用した培養感作リンパ球の量に比例した.培養上清はin vitroにおいてもラット初代培養肝細胞およびChang肝細胞をdose dependentに障害し,L929細胞に対する障害性はみられず,肝細胞障害性リンフォカインと考えられた.このリンフォカインはSephadex G-100カラムのゲル濾過により分子量は4万から9万の間に存在し,ノイラミニダーゼ処理によって活性の変化はみられなかったが,トリプシン処理,および56℃ 30分加熱処理により失活した.以上の成績からこのリンフォカインはリンフォトキシンとは異なり,肝細胞に特異性のある細胞障害性リンフォカインで,肝壊死を誘導するものと考えられた.

Proceedings Of The 21St Autumn Meeting From October 15th-17th, 1979-Maebashi, Japan

When the peripheral blood lymphocytes from patients with various types of hepatitis were stimulated in vitro with liver specific protein, lymphocyte transformation and MIF production were detectable in many cases, especially in chronic active hepatitis. The macrophage activating factor (MAF), a kind of lymphokines, was also detected in the culture medium of activated lymphocytes from patients who showed positive blastogenesis. The activated macrophages by MAF were shown to be cytotoxic to the separated liver cells causing the marked inhibition of albumin synthesis. MAF-containing culture supernatants of these active lymphocytes activated guinea pig macrophages which inhibited the albumin biosynthesis of the isolated liver cells. These observations suggest that the macrophagemediated cytotoxicity may play and role in pathogenesis of chronic active hepatitis.