间接血凝法检测抗Sm抗体和抗RNP抗体

应用间接血凝法测定抗Ｓｍ抗体和抗ＲＮＰ抗体。对不同疾病的检测结果表明，建立的该种方法与免疫电泳法结果无显著性差异（Ｐ＞０．０５）。对ＳＬＥ病４５例检测抗Ｓｍ抗体阳性率为１００％，抗ＲＮＰ抗体阳性率为９１％，抗Ｓｍ抗体可作为ＳＬＥ的特异性标志抗体，抗ＲＮＰ抗体在ＲＡ、ＰＳＳ、ＤＭ、ＭＣＴＤ病人中检出，其中ＭＣＴＤ病２３例，抗ＲＮＰ抗体阳性率高达９６％。且凝集效价高，可作为此病诊断的重要依据。间接血凝法具有操作简便、快速、敏感、特异性高、便于推广等特点，可代替免疫电泳法。     

Antibody penetration of viable human cells. I. Increased penetration of human lymphocytes by anti-RNP IgG.

Antibody penetration of viable cells and interaction with intracellular antigens may have major consequences for immunopathological processes in connective tissue diseases. We have reported previously that antibody can penetrate viable human lymphocytes. To assess further the role of antinuclear antibodies in this process, peripheral blood lymphocytes (PBMC) were incubated with FITC-conjugated IgG fractions from sera containing anti-RNP (anti-RNP IgG), Ro(SS-A), La(SS-B) and dsDNA antibodies and control sera for 24 h. Using crystal violet to quench cell surface staining, intracellular fluorescence of viable lymphocytes was quantified on the flow cytometer. It was noted that anti-RNP IgG entered 46.4 +/- 7.2% of lymphocytes which was significantly higher than anti-Ro(SS-A) (29.9 +/- 4.1%, P less than 0.05), La(SS-B) (22.0 +/- 7.5%, P less than 0.01) IgG and control IgG (28.8 +/- 2.1%, P less than 0.05) and not statistically different from anti-dsDNA IgG (32.6 +/- 14.3%). Inhibition experiments showed that the increased number of cells penetrated by anti-RNP IgG was a specific process. Time-course studies showed that anti-RNP IgG entry into cells was different from pooled control IgG. With anti-RNP IgG, positive-staining lymphocytes gradually increased in number from 12 to 24 h incubation, whilst with pooled control IgG, the peak was reached within 5 min. Dual staining experiments suggested that whereas both anti-RNP IgG and pooled control IgG entered B and NK cells, anti-RNP IgG also entered T cells. Using IgG F(ab')2 and Fc fragments from either anti-RNP IgG or pooled control IgG to compete with their FITC-conjugated counterparts indicated that the entry of anti-RNP IgG into-viable cells appeared to involve both F(ab')2 and Fc fragments, and pooled control IgG depended exclusively on the Fc portion of IgG. Further investigation by incubating anti-RNP IgG with 35S-methionine-labelled monocyte-depleted PBMC (MD-PBMC) suggested that anti-RNP IgG might react with the corresponding antigens either on the cell surface or within the cytoplasm.     

Anti-Sm and anti-RNP antibodies

Among anti-nuclear antibodies, anti-Sm and anti-RNP antibodies are of the utmost importance in clinical practice. Anti-Sm antibodies are directed against 7 proteins (B/B′, D1, D2, D3, E, F, G) that constitute the common core of U1, U2, U4 and U5 small nuclear ribonucleoprotein (snRNP) particles; B/B′, D1 and D3 are more frequently targeted. Anti-RNP antibodies react with proteins (70?Kd, A, C) that are associated with U1 RNA and form U1snRNP. Anti-Sm and anti-RNP antibodies are directed towards both discontinuous and linear epitopes which are either contained in the protein sequence or are post-translationally modified.

The assays to detect anti-Sm and anti-RNP antibodies are counterimmunoelectrophoresis (CIE), immunoblot, and ELISA, based on purified or recombinant proteins or synthetic peptides.

Anti-Sm antibodies are detectable in a percentage of SLE patients comprised between 5 and 30%; they are more prevalent in blacks and because of their high specificity for SLE have been included in the serological criteria for diagnosing the disease.

Anti-RNP are detectable in 25–47% of SLE patients; high titers of anti-RNP antibodies are diagnostic of mixed connective tissue disorder (MCTD). The measurement of anti-Sm and anti-RNP antibodies is more important in the diagnosis of SLE than in the follow-up of patients. However, anti-RNP antibodies are more prevalent in patients with Raynaud's phenomenon and are associated with milder renal involvement. On the contrary, anti-Sm antibodies are associated with the severity and the activity of renal involvement.

The specificity of anti-Sm antibodies, together with epidemiological data, suggest that Epstein-Barr virus infection has the potential to induce anti-Sm antibodies by molecular mimicry.

Anti-nuclear antibodies, a hallmark of the systemic autoimmune diseases, include several populations of antibodies with different specificities. Among them, anti-Sm and anti-RNP antibodies are of the utmost importance in clinical practice; in research, the study of the mechanisms inducing their production has opened up new perspectives and helped to elucidate the pathogenesis of autoimmune disorders.     

间接血凝法检测抗Sm抗体和抗RNP

应用间接血凝法测定抗Sm抗体和抗RNP抗体。对不同疾病的检测结果表明,我们建立的这种方法与免疫电泳法结果无显著性差异(P〉0.05)。对SLE病45例检测抗Sm抗体阳性率为100％,抗RNP抗体阳性率为91％。抗Sm抗体可作为SLE的特异性标志抗体,抗RNP抗体在RA,PSS,DM,MCTD病人中检出,其中MCTD病23例,抗RNP抗体阳性率高达96％,且凝集效价高,可作为此病诊断的重要依据。     

Autoantibody in a patient with chronic hepatitis C virus infection showing complete remission after interferon therapy

A 42-year-old woman was admitted to Kinashi Ohbayashi Hospital for liver dysfunction. She presented with hepatitis C viral infection accompanied by autoimmune hepatitis-like serological manifestations, such as antinuclear antibody (ANA), antismooth muscle cell antibody and especially anti-ribonucleoprotein (RNP) antibody and anti-SSB antibody. After interferon therapy, hepatitis C virus was not detected and ANA, anti-RNP antibody and anti-SSB antibody disappeared. To our knowledge, this is the first reported hepatitis C patient showing anti-RNP antibody and anti-SSB antibody, having complete remission after interferon therapy.     

Progressive facial hemiatrophy complicated by sclerodactyly,Raynaud’s phenomenon,anti-ribonucleoprotein antibody,and trigeminal nerve disturbance

Abstract

A Japanese woman was diagnosed as having progressive facial hemiatrophy when she was 26 years old. After 30 years, Raynaud’s phenomenon and sclerodactyly suddenly appeared; at the same time, positive rheumatoid factor and anti-ribonucleoprotein (anti-RNP) antibody were noted on serological examinations. When she was 60 years old, trigeminal nerve disturbance also appeared. The associations between progressive facial hemiatrophy, systemic scleroderma, and trigeminal nerve disturbance are interesting and should be discussed.     

Progressive facial hemiatrophy complicated by sclerodactyly, Raynaud’s phenomenon, anti-ribonucleoprotein antibody, and trigeminal nerve disturbance

A Japanese woman was diagnosed as having progressive facial hemiatrophy when she was 26 years old. After 30 years, Raynaud’s phenomenon and sclerodactyly suddenly appeared; at the same time, positive rheumatoid factor and anti-ribonucleoprotein (anti-RNP) antibody were noted on serological examinations. When she was 60 years old, trigeminal nerve disturbance also appeared. The associations between progressive facial hemiatrophy, systemic scleroderma, and trigeminal nerve disturbance are interesting and should be discussed.     

Mixed connective tissue disease in childhood

Since 1981, 21 children diagnosed with mixed connective tissue disease (MCTD) have been reported in detail in the literature in Japan. Overlapping clinical features and laboratory findings of these children were analyzed according to the established criteria of the Ministry of Health and Welfare, Japan. Mixed connective tissue disease in childhood typically begins with Raynaud's phenomenon preceded by several months or years with the appearance of other symptoms and signs including fever, arthralgia, myalgia, and/or progressive systemic sclerosis like skin manifestations. Serologically all the children with MCTD were positive for anti-ribonuclear protein (RNP) antibody with speckled-type antinuclear antibody. Hypergammaglobulinemia, positive rheumatoid factor, and normocomplementemia were characteristic. In general, prognosis is considered to be fairly good as opposed to systemic lupus erythematosus in childhood, but severe pericarditis/myocarditis or nephrotic syndrome can occur. Long-term follow-up study and improved laboratory detection of anti-ribonucleoprotein antibodies will be necessary for further characterization of MCTD in childhood, and for the improvement of therapy.     

同时检测抗SSA和抗RNP在诊断结缔组织病中的意义

目的探讨抗SSA和抗RNP在结缔组织病中出现的机率。方法采用双免疫扩散法(ID)和免疫印迹法(IBT)同时检测抗SSA和抗RNP。结果用ID法检测系统性红斑狼疮(SLE)患者抗SSA阳性率远高于抗RNP(P<0.05),混合性结缔组织病患者中抗RNP阳性率l00%高于抗SSA的19%(P<0.001),结缔组织病患者中抗SSA阳性率82.8%亦远高于抗RNP的14.1%(P<0.05)。结论ID法比IBT法检测抗SSA较全面,使用ID法和IBT法同时检测抗SSA和抗RNP,可以提高临床诊断的正确性,减少漏诊。