Antinuclear factor and other antibodies in blood and liver diseases

Meta-analysis: diagnostic accuracy of antinuclear antibodies, smooth muscle antibodies and antibodies to a soluble liver antigen/liver pancreas in autoimmune hepatitis

Background

Antinuclear antibodies (ANA), smooth muscle antibodies (SMA) and antibodies to a soluble liver antigen/liver pancreas (anti-SLA/LP) are useful markers that can help clinicians to diagnose and classify autoimmune hepatitis (AIH).

Objectives

To determine whether ANA, SMA and anti-SLA/LP help to accurately diagnose patients with AIH.

Search strategy

The PubMed, CNKI, WANFANG, and SinoMed databases were accessed to retrieve studies published in English and Chinese. Studies published up to October 2013 were reviewed.

Selection criteria

Studies on the diagnostic value of ANA, SMA or anti-SLA/LP in the diagnosis of known or suspected AIH were included.

Data collection and analysis

Two authors evaluated studies independently and rated their methodological quality using quality assessment of diagnostic accuracy studies (QUADAS) tools; relevant data were abstracted. The random-effects method was used to summarize sensitivities, specificities, positive and negative likelihood ratios, and diagnostic odds ratios (DORs) from all 29 studies.

Results

The pooled sensitivity, specificity, positive and negative likelihood ratios, and DOR for ANA were 0.650 (95% confidence interval [CI], 0.619 to 0.680), 0.751 (95%CI, 0.737 to 0.764), 3.030 (95%CI, 2.349 to 3.910), 0.464 (95%CI, 0.356 to 0.604), and 7.380 (95%CI, 4.344 to 12.539), respectively. For SMA, the values were 0.593 (95%CI, 0.564 to 0.621), 0.926 (95%CI, 0.917 to 0.934), 11.740 (95%CI, 7.379 to 18.678), 0.449 (95%CI, 0.367 to 0.549), and 31.553 (95%CI, 17.147 to 58.060), respectively. Finally, for anti-SLA/LP, the values were 0.194 (95%CI, 0.168 to 0.222), 0.989 (95%CI, 0.985 to 0.993), 11.089 (95%CI, 7.601 to 16.177), 0.839 (95%CI, 0.777 to 0.905), and 16.867 (95%CI, 10.956 to 25.967), respectively.

Authors’ conclusions

ANA provided moderate sensitivity and specificity, while SMA gave moderate sensitivity and high specificity, and anti-SLA/LP exhibited low sensitivity and high specificity. All three antibodies were limited by their unsatisfactory sensitivities and lack of consistency.

Using the antinuclear antibody test to diagnose rheumatic diseases: when does a positive test warrant further investigation?

The anti-nuclear antibody (ANA) test is ordered commonly as a screening test for rheumatic diseases. Although ANA positivity is highly sensitive for certain rheumatic diseases, the presence of ANA is nonspecific and can be associated with numerous nonrheumatic factors, including environmental exposures, malignancies, drugs, and infections. This article describes a practical approach for physicians when evaluating patients using a positive ANA test. In the absence of connective tissue disease symptoms, the ANA test has minimal clinical significance in diagnosing rheumatic diseases. Understanding how to use ANA test results appropriately may reduce unnecessary referrals and costly workups.

A 50-year experience with autoimmune hepatitis: and where are we now?

BACKGROUND

Autoimmune hepatitis (AIH) as chronic active hepatitis became recognized in the 1940s as a progressive hyperglobulinemic disease affecting younger women attributed to persisting virus infection of the liver: autoimmunity then was barely on the horizon.

EARLY OBSERVATIONS

The lupus erythematosus (LE) cell reported in 1948 signified the presence of antinuclear autoantibodies, promoting perceptions of autoimmunity in certain chronic diseases. Recognition of LE cells in chronic hepatitis led to the designation of 'lupoid hepatitis', with autoimmunity further substantiated by anti-cytoplasmic autoantibodies detected by complement fixation. Next a serum reactant with smooth muscle of rodent stomach was found to have a wider distribution and became identified as an autoantibody to filamentous (F) actin. Therapy with corticosteroids proved effective, particularly combined with azathioprine. Various trials showed greatly improved survival and established modern therapy of AIH. An HLA-based predisposition (B8, DR3) was the first pointer to a genetic etiology.

RECENT ADVANCES

Recombinant or purified autoantigenic substrates have led to automated assays, which, together with improved immunofluorescence procedures, allow serological confidence in diagnosis and institution of effective immunosuppressive therapies. The liver-kidney 'microsomal' autoantigen reactive with cytochrome P450 2D6 distinguishes two serological types of AIH that appear pathogenetically distinct. Molecular characterization of antigens and epitopes remains wanting in type 1 AIH.

FUTURE PROSPECTS

The challenge remains with both types of AIH to elucidate in molecular terms the genetic and environmental basis of pathogenesis from initiation to ultimate progression and cirrhosis (when inadequately treated). Advancing technologies are bringing this goal closer to being attainable.

Pure red cell aplasia--evidence for an inhibitory action of the bone marrow adherent cell layer

Evidence is presented for an inhibitory action of the bone marrow adherent cell layer on erythropoiesis in a case of pure red cell aplasia. Cultures of the patient's bone marrow with autologous and normal plasma showed normal numbers of CFU-C, but total absence of BFU-E. There was no inhibition of BFU-E when normal bone marrow was cultured with the patient's plasma. T-cell depletion of the patient's bone marrow did not affect these results, but after removal of the adherent cells, normal numbers of BFU-E were cultured. These observations suggest that the adherent cells, which are predominantly macrophages, were responsible for the inhibitory action on erythropoiesis.

Historical reflections on autoimmune hepatitis

Autoimmune hepatitis (AIH), initially known as chronic active or active chronic hepatitis (and by various other names), first came under clinical notice in the late 1940s. However, quite likely, chronic active hepatitis (CAH) had been observed prior to this and was attributed to a persistently destructive virus infection of the liver. An earlier (and controversial) designation in 1956 as lupoid hepatitis was derived from associated L.E. cell test positivity and emphasized accompanying multisystem features and immunological aberrations. Young women featured prominently in early descriptions of CAH. AIH was first applied in 1965 as a descriptive term. Disease-characteristic autoantibodies were defined from the early 1960s, notably antinuclear antibody (ANA), smooth muscle antibody (SMA) and liver-kidney microsomal (LKM) antibody. These are still widely used diagnostically but their relationship to pathogenesis is still not evident. A liver and disease specific autoantigen has long been searched for but unsuccessfully. Prolonged immunosuppressive therapy with predisolone and azathioprine in the 1960s proved beneficial and remains standard therapy today. AIH like many other autoimmune diseases is associated with particular HLA alleles especially with the "ancestral" B8, DR3 haplotype, and also with DR4. Looking forwards, AIH is one of the several enigmatic autoimmune diseases that, despite being (relatively) organ specific, are marked by autoimmune reactivities with non-organ-specific autoantigens. New paradigms are needed to explain the occurrence, expressions and pathogenesis of such diseases.

HCV-marker-positive autoimmune-type chronic active hepatitis: a possible relation between HCV infection and liver autoreaction

This study focused on 32 patients who were diagnosed as having autoimmune hepatitis based upon clinical and histological factors. Fifteen of these patients were positive for HCV-RNA and for one of the HCV-related markers tested, including anti-C100, ELISA II, and RIBA 2 (Group 2). The remaining 17 patients were negative for all HCV-related markers (Group 1). Clinical factors in the two groups, including the frequency of autoantibodies, serum levels of aminotransferase and gammaglobulin, HLA phenotypes, and the response to corticosteroid treatments, were compared. The titer of serum anti-nuclear antibodies and the level of serum aminotransferase at initial diagnosis were significantly higher in Group 1 than in Group 2. Furthermore, the genetic background of the two groups, as indicated by HLA phenotypes, differed. All cases in Group 1 were HLA-DR4-positive, whereas only 60% of those in Group 2 cases had HLA-DR4. Also, all cases in Group 1 but only 66.7% of the cases in Group 2 showed good clinical responses to corticosteroid treatment. Finally, no cases of HCV-related-marker-positive autoimmune hepatitis (Group 2) had antibodies for LKM, suggesting that these cases were clinically different from type II autoimmune hepatitis. These data indicated that immunosuppressive treatment might be the preferred initial treatment in patients who either satisfy the criteria for AIH or who are sero-positive for an HCV-marker.

Anti-cardiolipin antibodies in infectious mononucleosis react with the membrane of activated lymphocytes

To elucidate the mechanisms of autoantibody induction in infectious mononucleosis (IM), we have studied sera from 35 patients with IM with enzyme-linked immunosorbent assays using purified antigens. In the IM group 37% had IgM antibodies to cardiolipin above the normal range (mean plus 2 standard deviations of control sera). Significantly elevated frequencies of antibodies to actin (26%) and cytoskeletal antigens (97% versus 29% in normal sera) were also found, but levels of IgM rheumatoid factors, IgM antibodies to single-stranded DNA and antibodies to ribonucleoproteins (nRNP/Sm, Sm and La) were normal. Affinity purified anti-cardiolipin antibodies reacted with the cell membrane of transformed lymphocytes but not with resting cells, suggesting that cell activation was required for the expression of antigenic epitopes. Our data suggest that the autoantibody response in IM is restricted to two classes of autoantigens: cytoskeletal and cell membrane antigens. The appearance of antigenic epitopes on EBV-transformed lymphocytes could be a mechanism for the generation of anti-cardiolipin antibodies in infectious mononucleosis. Similar mechanisms could operate in autoimmune rheumatic disease.

Chlamydial respiratory infection in childhood and spurious immunoglobulin M

The role of Chlamydia trachomatis was investigated in lower respiratory tract infections in 254 children. The organism was not isolated in any child but Bordetella pertussis was isolated from 65. Two of the latter and one of the remaining 189 children with negative isolation, however, had immunoglobulin M (IgM) antibodies to Chlamydia trachomatis (titers of 1:64, 1:64 and 1:128). Exhaustive absorption of the sera with bordetella antigen left the chlamydial titers unchanged, thus excluding the possibility of cross-reactivity with bordetella antigen. To determine whether nonspecific stimulation of B lymphocytes played a role, sera from 72 children with infectious mononucleosis were examined. Chlamydial IgM antibodies (greater than or equal to 1:64) were detected in 14 of these sera, significantly more often than in other acute childhood infections (p = 0.002). Serotyping showed that these antibodies had a heterogeneous specificity in different sera and a reactivity pattern suggesting they were monoclonal. The association found between chlamydial IgM antibodies and Epstein-Barr virus infection implies that there is nonspecific production of these antibodies in infectious mononucleosis, suggesting that similar nonspecific antibody production could occur in other infections. This might explain the chlamydial IgM found in children with lower respiratory tract infections in whom chlamydial infection could not be confirmed by isolation.

Acute disseminated encephalitis documented by magnetic resonance imaging and computed tomography. Report of a case

A 16-year-old girl developed left hemispheric deficits, which were followed by clouding of consciousness, quadriplegia, and subcortical blindness. Although we could not demonstrate a recent viral infection, the clinical features, laboratory and radiologic findings strongly suggested the diagnosis acute disseminated encephalitis. Cerebrospinal fluid abnormalities incompletely correlated with the clinical course. In contrast, X-ray computed tomography and particularly magnetic resonance imaging of the head closely reflected disease and improvement.

Nuclear membrane-staining antinuclear antibody in patients with primary biliary cirrhosis

An antinuclear antibody specific for nuclear membrane (ANMA) was observed by the immunofluorescence method in sera from patients with primary biliary cirrhosis (PBC). ANMA was present in 18 of 63 PBC sera (28.5) and in 1 of 431 control sera (0.2%). Its reaction appeared as a thin fluorescent ring confined to the nuclear envelope and was more evident when the sera were highly diluted and the fluorescence, due to frequently associated antimitochondrial antibody, faded. The ANMA fluorescent pattern was confirmed by indirect immunoperoxidase staining. ANMA was seen on both tissue cryostat sections and HEp-2 cells. It was a poorly or non-complement-fixing IgG, specific for an antigen resistant to DNase I, RNase, and trypsin. The significance of its presence in PBC in unknown at present. Identification of its antigen with one of the centromeric antigens is suggested.

Incidence of anti-intermediate filament antibody in serum samples of students with suspected glandular fever

Serum samples from 40 students with suspected infectious mononucleosis were tested for the presence of antibodies to intermediate filaments (AIFA) of the cytoskeleton. Twenty had antibodies to the Epstein-Barr virus capsid antigen before their illness, and during it their sera remained negative by the Paul-Bunnell test. The other 20 patients did not have antibodies to the Epstein-Barr virus capsid antigen before their illness and seroconverted during the illness. These patients (true infectious mononucleosis group) developed positive Paul-Bunnell tests. Sera from normal subjects (blood donors) were also tested for AIFA. AIFA was present in titres greater than 1/10 in 80% of the infectious mononucleosis group (mean titre 1/40-1/80), 10% of the Paul-Bunnell negative glandular fever group, and 8.5% of the normal blood donors.

Evidence for relationships between antiperinuclear and IgG rheumatoid factor

Antiperinuclear factor (APF) and IgG-rheumatoid factor (IgG-RF) has been found in 64% and 48% of cases of rheumatoid arthritis, 36% and 50% of cases of psoriasis and 31% and 45% of cases of primary Sjögren's syndrome. A close relationship between APF and IgG-RF is suggested by statistical and experimental data. Purified IgG-RF has some degree of APF activity.

Circulating IgG complexes in primary biliary cirrhosis. A serial study in forty patients followed for two years

Several antibodies are present in sera of patients with primary biliary cirrhosis (PBC). We have looked for evidence of antigen-antibody complexes in sera of PBC assuming that some of the antibodies may circulate complexed with an antigen. The Raji cell radioimmunoassay, which determines complement-bound immune complexes, was used to determine the levels of such complexes in serial samples of sera from forty patients with PBC followed for 2 years. Twenty-four patients (60%) were found to have significantly elevated levels of circulating complexes. In the majority they were detected from the beginning of the study and the high levels persisted. In seven patients whose sera initially had normal levels of complexes, the levels increased to become abnormal during the following year. These complexes sedimented at greater than or equal to 19S in the majority of patients studied. The mean level of C3 but not C4 was lower in patients with elevated complexes than in those with normal complexes. A significant correlation was observed between the presence of elevated complexes and the severity of the inflammatory cell infiltrate surrounding intrahepatic portal tracts and serum IgG and IgM levels. There was also a significant correlation with titres of antimitochondrial antibody, but not with the histological stage of disease or with the collagen and copper content of the liver. Although the method of detection of immune complexes is indirect and the antigen is unknown, the presence of such high levels of complexes suggests a possible role of immune complexes in the pathogenesis of PBC.

Rheumatoid arthritis--a sequel to HBsAg hepatitis

Reported here is the first case of classic rheumatoid arthritis emerging in the setting of hepatitis B surface antigen (HBsAG)-positive viral hepatitis. Polyfocal arthritis and myalgia, lymphadenopathy and constitutional symptoms were the presenting manifestations of anicteric hepatitis in this 23 year old man. Smooth muscles antibodies, HBsAg and "rheumatoid" factor were demonstrated initially. The hepatocellular disease, biopsy-proved, resolved completely and without recurrence; clinically and serologically. Latex test positivity persisted, increasing in titer, and polyarthritis progressed to fulfull criteria for classic rheumatoid arthritis, with erosions on roentgenogram and characteristic synovial disease. After 60 months of follow-up, the rheumatoid synovitis has continued to progress despite appropriate therapy. The arthritis of viral hepatitis and the significance of rheumatoid factor in association with hepatocellular disease are discussed.

Studies on the heterophile antibodies of infectious mononucleosis. I. Separation of four antibody populations, one of which contains lymphocytotoxic activity

With the aid of insolubilized immunoadsorbents made with glycoproteins, extracted from cow red blood cells (RBC), and with guinea-pig kidney tissue, heterophile antibody populations of the Paul--Bunnell type and the Forssman type were eluted from infectious mononucleosis sera. Two Paul--Bunnell-type antibody populations were separated on the basis of their affinity for cow RBC antigens. The lymphocytotoxic antibodies in the infectious mononucleosis sera were eluted among the low-affinity Paul--Bunnell antibodies.

The occurrence of autoantibodies in infectious mononucleosis

Autoantibodies were looked for by immunofluorescence (IFL) in seventy-seven cases of infectious mononucleosis (IM) at the onset of symptoms and on recovery, to determine the time of appearance, duration and range of these responses, and to correlate them with serum immunoglobulin and EB virus antibody titres. Antibodies to lymphocyte membrane demonstrated by IFL, now identified with lymphocytotoxins, were present in 46% of patients in the acute stage, persisting for less than 7 weeks. Antibodies to smooth muscle (SMA) or to contractile fibres in other tissue cells including human thyroid and rat hepatocytes, were present in over 70% of cases, some being entirely of IgM class. The highest titres occurred soon after onset and these antibodies also disappeared during convalescence. By contrast ANA, mitochondrial, microsomal and reticulin antibodies, also thyroid and gastric organ-specific reactivity were seen only occasionally owing to the young age group of the patients. In individual cases there was no correlation between the appearance of lymphocyte antibodies and SMA, or between these and the EB virus antibody titres.

The autoantibodies produced in this disease are highly selected. It is suggested that clones of B cells are stimulated to make these antibodies by virtue of being infected with EB virus, and that the T-cell clones in the circulation are more likely expanded in order to terminate the infection.

Immunoglobulins and EB virus antibodies in infectious mononucleosis

Antibodies to EB virus capsid, EB virus complement-fixing antibodies and IgM, IgA and IgG immunoglobulins were estimated in sera from seventy-four patients with infectious mononucleosis, eighty-nine control patients (mostly with infectious diseases) and 232 healthy medical students and nurses. Complement fixing (but not virus capsid) antibodies were much lower in patients tested during active infectious mononucleosis than in patients tested during late convalescence or in controls, a disparity which could form the basis of a diagnostic test. Immunoglobulin levels were higher in patients with active infectious mononucleosis than in controls and, when tested 6 months to 2 yr later, were still higher than those in healthy individuals.

Studies on red cell aplasia. V. Presence of erythroblast cytotoxicity in G-globulin fraction of plasma

The marrow cells of a patient with pure red cell aplasia markedly increased their rate of heme synthesis when they were freed from the host environment and were incubated in vitro. When the red cell aplasia was treated with cyclophosphamide and prednisone, marrow cell incorporation of (59)Fe into heme in vitro increased several weeks before a reticulocytosis was apparent, and was the earliest effect noted. The plasma gammaG-globulins of this patient inhibited heme synthesis by normal marrow cells or the patient's own marrow cells obtained after remission of the disease. Since the inhibition of heme synthesis could be the result of damage to erythroblasts, the patient's posttreatment marrow cells or normal marrow cells were labeled with (59)Fe and were then incubated with the patient's pretreatment, treatment, and posttreatment gammaG-globulins as well as normal gammaG-globulins. At the end of this incubation the supernatant and cells were separated and counted. Heme was extracted and also was counted. Treatment of the cells with the patient's pretreatment gammaG-globulins resulted in a release of 40% of the radioactive heme from the cells. This represented the loss of radioactive hemoglobin and was an index of erythroblast cytotoxicity. A progressive disappearance of the cytotoxic factor in the gammaG-globulins occurred in the 3 wk period preceding the onset of reticulocytes in the patient's blood. Posttreatment and normal gammaG-globulins did not produce this effect and increased injury of red cells and lymphocytes was not produced by the patient's pretreatment gammaG-globulins. These studies demonstrate a method for measuring erythroblast cytoxicity and show that red cell aplasia is associated with gammaG-globulins that specifically damage erythroblasts. Whether interference with new erythroblast development also occurs and contributes to the inhibition of heme synthesis has not yet been ascertained.

Studies on red cell aplasia. I. Demonstration of a plasma inhibitor to heme synthesis and an antibody to erythroblast nuclei

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IMMUNOLOGICAL DISTURBANCES IN MYASTHENIA GRAVIS WITH A REPORT OF HASHIMOTO'S DISEASE DEVELOPING AFTER THYMECTOMY

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