Evaluation of the simultaneous estimation of anti-dsDNA and anti-ssDNA antibodies for clinical purposes.

The double-antibody solid-phase assay for DNA antibodies permits simultaneous and quantitative determination of antibodies to dsDNA and ssDNA. Using this method, 170 sera, mainly ANA-positive, were examined for the presence of anti-dsDNA and anti-ssDNA to assess the role of these antibodies in the ANA reaction. It was found that in the SLE group of patients, their ability to respond to dsDNA was correlated with the multiorgan symptomatology of disease. Anti-ssDNA titres are also highest in this group. However, anti-ssDNA titres predominate over anti-dsDNA in other collagen diseases. This predominance increases as we progress from the SLE group to undefined mild collagenosis, because the response to dsDNA decreases more than the response to ssDNA. This observation suggests that the clinical manifestation of the collagen diseases and multiorgan manifestation of SLE is linked with the pattern of response to DNA in the majority of cases. In conclusion, it appears that the determination of both ssDNA and dsDNA antibodies can be of value for the prognosis and management of patients with connective tissue disease.     

Heterogeneity of anti-idiotypic antibodies to anti-DNA antibodies in humans.

Serum antibodies in some patients with systemic lupus erythematosus (SLE) were found to have specificity to idiotypes (Id) of 0-81 (human monoclonal anti-single-stranded DNA (ssDNA) antibody) but not to Id of NE-1 (human monoclonal anti-double-stranded DNA (dsDNA) antibody) or pooled human IgM. The interaction of the antibodies and 0-81 was blocked by the co-existence of free ssDNA. Some of SLE sera also showed preferential binding to Id determinants of NE-1, which included the antigen-binding sites of the dsDNA antibody. Some other SLE sera reacted with both Id of 0-81 and NE-13. Thus, there was heterogeneous population among human anti-Id autoantibodies to anti-DNA antibodies. The anti-Id activity was commonly detected in inactive SLE sera, and less frequently in normal controls, suggesting some regulatory role for anti-Id antibodies in the production of autoantibodies.     

Double-stranded DNA antibodies: a comparison of four methods of detection.

Thirty-four antinuclear antibody (ANA) positive systemic lupus erythematosus (SLE) sera were tested for antibodies to double-stranded DNA (dsDNA) simultaneously using Farr, haemagglutination, Crithidia luciliae (CL) kinetoplast fluorescence and human metaphase chromosome fluorescence assays. Significant correlation (p less than 0 x 05) was found between the Farr and CL assays, with the two fluorescence tests (CL and metaphase) displaying the greatest degree of association (p = 0 x 00001). No correlation could be demonstrated between the haemagglutination test and any of the other three assays. Six hundred and ninety-one sera from patients with a range of provisional rheumatological diagnoses were prospectively analysed for dsDNA antibodies using Farr and metaphase assays. A correlation coefficient of 0 x 84 was obtained between the two assays. The metaphase assay provides comparable results to other more established assays, and because it is simple, reliable and sensitive, it should be seriously considered for routine use in testing for dsDNA antibodies.     

Temporary breakdown of immunological tolerance to dsDNA and nucleohistone antigens in rabbits infected with rinderpest virus.

The rabbit-passaged L strain of rinderpest virus (RV) causes the transient induction of anti-nuclear antibodies (ANA) in rabbits. It has been shown by an indirect immunofluorescence test that the target antigens of these ANA are DNA and/or DNA-histone complexes (nucleohistone). Here detailed examinations of the target antigens were carried out by ELISA, and it was revealed that rabbit sera contained three types of antibodies: antibodies reacting equally with both dsDNA and ssDNA; those reacting with ssDNA alone; and those reacting with nucleohistone. Epitopes recognized by the third type consisted of complexes of dsDNA and H2A + H2B or of dsDNA and H2B. All types of antibodies were antigen specific. Since the diversity of ANA among experimental rabbits was large, it was suggested that genetic background is important in the induction of anti-dsDNA antibodies in this system. Moreover, early induction of antibodies to nucleohistone and the rapid disappearance of ANA suggest that B cell proliferation/maturation for continuous production of ANA requires factors other than RV infection. This system may help elucidate the mechanisms of ANA induction and the development of autoimmune diseases.     

Evaluation of an automated chemiluminescent immunoassay kit for antinuclear antibodies in autoimmune diseases

The identification of antinuclear antibodies (ANA) is an essential step in the diagnosis of different autoimmune diseases. The gold standard method for their detection is immunofluorescence assay. However, this is a subjective and laborious method, thus a need for simplified objective methods has aroused. In the current work, we evaluated such automated method, the LIAISON^® (DiaSorin, Italy) for the detection of ANA. A total of 242 sera were analyzed including 67 from healthy subjects, 107 from primary biliary cirrhosis (PBC) patients, 20 from scleroderma patients and 48 from patients with Sjögren’s syndrome. All sera were analyzed using the automated chemiluminescent immunoassays, LIAISON^® for the presence of ANA (kit No. 310300). Positive samples were further analyzed for the presence of antidouble-stranded DNA (dsDNA) and autoantibodies to 6 extractable nuclear antigens (ENA) of the LIAISON^® (kits No. 310330 and 310331). Negative samples were further analyzed by Blueblot ANA assay (D-TEK, Belgium) or BlueDot Liver (D-TEK, Belgium) as appropriate. The LIAISON^® specificity for ANA screening was 97 %. ANA positivity was determined in 80 % of all patients. The sensitivity was 95.5 % in scleroderma, 83 % in PBC and 72.9 % in Sjogren’s syndrome. ENA was positive in all ANA-positive scleroderma and Sjögren’s sera and in 27 % of ANA-positive PBC sera. Among scleroderma or Sjögren patients that were ANA negative, 4 samples were positive for anti-SSA and 2 for RNP-68 utilizing Blueblot assays. M2 protein was found in 1 out of the ANA-negative PBC patients. The LIAISON^® ANA screen is specific and sensitive for the evaluation of ANA in patients with primary biliary cirrhosis, scleroderma and Sjögren’s syndrome.     

Measurement of antibody to poly (adenosine diphosphate-ribose): its diagnostic value in systemic lupus erythematosus.

Poly (ADP-ribose) and dsDNA binding activity have been measured in sera from 61 patients with systemic lupus erythematosus (SLE) and 188 control sera from 20 normal individuals, 144 patients with clinically similar diseases and 24 patients with drug-induced anti-nuclear antibodies (ANA). Elevated poly (ADP-ribose) binding was not observed with normal sera. Five of 144 samples from diseases entering the differential diagnosis of SLE gave raised poly (ADP-ribose) binding compared with 12 in the 125I-dsDNA binding. Only two of these false positive samples gave elevated binding in the 14C-dsDNA assay. The apparent high specificity of the poly(ADP-ribose) assay was not observed with samples containing drug-induced ANA where 62% had elevated binding values. The frequency with which the poly(ADP-ribose) assay was positive with SLE sera (sensitivity) was lower than either of the dsDNA assays. This low sensitivity and the high rate of false positives in patients with drug-induced ANA limit the value of the poly(ADP-ribose) assay as a diagnostic test for SLE. However the restriction of poly(ADP-ribose) antibody to SLE and patients with drug-induced ANA together with the known role of poly(ADP-ribose) in DNA excision repair suggest that the antibody may be of fundamental significance.     

On opportunist infections by Trypanosoma lewisi in humans and its differential diagnosis from T. cruzi and T. rangeli

Trypanosoma lewisi is a cosmopolitan species originally found in Rattus spp., being nonpathogenic, host-restricted, and transmitted by rat fleas. This species has been recorded as an opportunist blood parasite of human beings mainly in Asia, with a case in Africa. In Brazil, this species was recently recorded in captive monkeys. As T. lewisi can share vertebrate hosts both with Trypanosoma rangeli and Trypanosoma cruzi, some markers for the differential diagnosis of these species were examined and discussed herein. The identification of T. lewisi was based on morphological features of bloodstream stages at the initial phase of infection in mammals, isoenzyme electrophoresis at the MDH locus, and PCR products of kinetoplast DNA (kDNA) minicircles using the primers TC121/TC122.     

Anti-argonaute2 (Ago2/Su) and -Ro antibodies identified by immunoprecipitation in primary anti-phospholipid syndrome (PAPS)

Objectives. Primary anti-phospholipid syndrome (PAPS) is an autoimmune condition defined by anti-phospholipid antibodies (aPL) and thrombotic or obstetric events. Some PAPS can evolve into systemic lupus erythematosus (SLE) during follow-up. Few studies systematically examined lupus autoantibodies and their clinical significance in PAPS. The aim of our study is to analyze the clinical and laboratory correlations with lupus-related autoantibodies, detected by immunoprecipitation (IP), a technique not yet systematically applied to investigate autoantibodies in this condition.

Methods. Sera from 52 PAPS patients were screened by indirect immunofluorescence (IIF) antinuclear antibodies (ANA), IP of ³⁵S-labeled K562 cell extract, and ELISA [anti-Argonaute2 (Ago2, Su), 60kRo, 52kRo, La, dsDNA)]. Anti-Ago2/Su positive sera were also tested for anti-GW bodies (GWBs) by IIF double staining, using rabbit anti-Rck/p54 serum.

Results. First, 56% of PAPS patients (29/52) were ANA positive, mainly with speckled pattern. Anti-Ago2/Su antibodies were found in 13% (7/52), anti-Ro/SSA in 10% (5/52), anti-La in one case. The clinical profile of patients did not seem to be related to the presence of these antibody specificities. However, levels of IgG anti-β2 glycoprotein I antibodies were lower in anti-Ago2/Su positive patients (p = 0.02). None of anti-Ago2/Su or —Ro patients developed SLE during a 2-year follow-up. Ago2 is a key component of GWBs, however, only 1/7 anti-Ago2/Su serum showed a typical cytoplasmic GWBs staining.

Conclusions. Anti-Ago2/Su and -Ro antibodies are the two autoantibodies detected by IP in our PAPS cohort. Clarifying why Ago2/Su and Ro are specific targets of autoimmunity may help to understand the mechanisms of autoantibody production.     

Évaluation du kit Diasorin Liaison® dsDNA pour la détection des anticorps anti-DNA natif

Screening and quantification of anti dsDNA antibodies are useful for positive diagnosis and follow-up of Systemic Lupus Erythematosus (SLE). Various assays exist based on different techniques which can influence the results. This study evaluated the specificity and the sentitivity of the Liaison^® dsDNA Diasorin assay for the detection of anti dsDNA antibodies. We compared the results with those obtained with ELIA^® dsDNA Pharmacia routinely used in our laboratory. The study has involved the sera of 153 systemic lupus erythematosus and 78 controls. The control group included 54 other autoimmune diseases and 24 patients without autoimmune markers. Liaison^® dsDNA (Pharmacia) assay offers a sensitivity of 91,5% and a specificity > 99%. Correlation with the ELIA^® dsDNA assay is 0,68. The automated Liaison^® dsDNA Diasorin assay demonstrates its value for the detection and quantification of anti dsDNA antibodies in SLE patients.     

Evaluation of diagnostic tests for antinuclear antibodies in rheumatological practice

To investigate and compare the accuracy and usefulness of diagnostic tests for antinuclear antibodies (ANA) a cross‐sectional study of sera derived from patients admitted to the Department of Rheumatology was tested for the presence of ANA using either indirect immunofluorescence on HEp‐2 cells, indirect immunoperoxidase techniques on HEp‐2 cells and mouse kidney, or two commercial enzyme‐linked immunosorbent assays (ELISA). The diagnostic sensitivity and predictive values of the tests were calculated and compared. The accuracy of tests was compared using receiver‐operating characteristics (ROC) methodology. All ANA‐positive sera were further analysed for the presence of antibodies against extractable nuclear antigens (anti‐ENA) and anti‐DNA. A moderate to good agreement was found between tests, with κ ranging from 0.469 to 0.659. Highest sensitivity for systemic lupus erythematosus (SLE; 93.3%) and primary Sjögren's syndrome (SS; 70%) was found using immunofluorescence on HEp‐2 cells. Immunofluorescence on HEp‐2 cells performed statistically better than the other tests in predicting SLE but not SS. All tests except mouse kidney showed good and comparable performance in detecting sera with anti‐ENA and anti‐DNA. At the given cut‐off values indirect immunofluorescence on HEp‐2 cells performed best. All assays except mouse kidney showed performance characteristics sufficient for use in routine analysis of ANA.     

A solid-phase radioimmunoassay for anti-SNP antibodies.

A highly sensitive and discriminatory solid-phase radioimmunoassay has been developed to detect anti-SNP antibodies in sera. Polystyrene tubes are coated with SNP and incubated with the test sera. The fixed antibodies are detected by a double layer technique using rabbit anti-human γ-globulin antiserum followed by incubation with a ¹²⁵I-labelled sheep anti-rabbit γ-globulin antiserum. Results are expressed in ng of the ¹²⁵I reagent fixed by 30 ωl of serum. The mean binding of 47 normal human sera was 22 ng ± 12 ng: 22/50 SLE sera gave over 34 ng binding. The specificity of the assay was studied in 3 different types of experiment: inhibition of the binding of positive sera either by pre-incubation with NDNA, SNP or RNA, DNAse I digestion of the SNP coated tubes, and incubation of SNP coated tubes with sera of known reactivity. It was shown that the solid-phase assay detects mainly antibodies directed against NDNA; however antibodies directed against the DNA-protein complex or the protein alone can easily be detected. Our results obtained with the solid-phase assay correlated well with those of the Farr assay. However, this new assay presents major improvements: it is simple, highly reproducible, and avoids the need for labelled antigen. A single labelled antiglobulin reagent allows identification of the class or subclass of reactive antibodies in a given species. Quantitation is more precise, particularly for sera containing high amounts of antibodies.     

Study of procainamide hapten-specific antibodies in rabbits and humans

Procainamide (PA) is the drug most commonly associated with the induction of autoantibodies and drug-related lupus (DRL). While the majority of these patients express autoantibodies, antibodies to the parent drug and metabolites, PA-hydroxylamine (PAHA) or nitroso-PA (NOPA), have not been reported in humans.Hapten-carrier conjugates were prepared using human hemoglobin (HgB) or autologous rabbit erythrocytes with PAHA or NOPA. PA was conjugated to rabbit serum albumin (RSA) or egg albumin (OVA) via diazotization and condensation methods. Rabbits were immunized with hapten conjugates in Freund's adjuvant. These hapten-carrier compounds (5 – 10 μg/ml) were used as test antigens for antibodies in sera from the rabbits and 40 patients on chronic PA treatment, 10 SLE patients, 33 elderly and 20 young normal controls by ELISA. Type I and II collagens were also used as test antigens for human sera.Sera from rabbits immunized with the PA compounds had elevated IgG antibody values to PA, PAHA and NOPA, but no autoantibodies. Absorption of the rabbit sera with the PA compounds reduced the antibody levels; ssDNA and histones failed to inhibit the total binding values. Mean binding to PA - OVA was 0.95 ± 0.41 for PA patients and 1.37 ± 0.26 standard error of means (S.E.M.) in the SLE patients compared to 0.37 ± 0.14 S.E.M. in the normal sera (P⩽0.05); similar binding values to PAHA - HgB and NOPA - HgB were also observed. Sixty-eight percent of the PA patients had antibodies to type II collagen. Elevated binding values to PA compounds were inhibited by absorption of human sera with ssDNA or total histones; absorption with PA or PAHA had no significant effect. These findings suggest that sera from PA patients containing high titers of autoantibodies cross-react in vitro with unrelated antigens.     

Antinuclear antibodies in patients on anticonvulsant therapy

Antinuclear antibodies to calf thymus nuclei, NP, DNA, sDNA, sNP and Sm antigen were investigated in sera from 170 patients on various programmes of prolonged anticonvulsant treatment. Findings were compared to those on 214 tuberculous patients on isoniazid, 109 SLE patients and 66 healthy subjects.

Patients on anticonvulsants had a significantly higher incidence of ANA to DNA, sDNA, sNP and Sm antigen than the controls but had a lower incidence of ANA to all antigens, except sNP, than the SLE patients. Patients on isoniazid did not have DNA antibodies, but had antibodies to whole nuclei and to NP which were practically absent in the anticonvulsant group.

Of all patients on anticonvulsants only those receiving hydantoins had ANA to Sm antigen, while those receiving only primidone had antibodies to sNP but no antibodies to DNA.

Alteration of sNP with isoniazid did not result in an increased incidence of ANA in the anticonvulsant group as it does in isoniazid treated subjects.

It is concluded that the SLE-activating properties of diverse anticonvulsants probably resides in their potential to induce ANA. Although all anticonvulsants elicit ANA directed primarily to sNP, each may do so by different mechanisms or by altering different sites in the sNP molecule. The mechanisms by which anticonvulsant and isoniazid intake results in ANA probably differ.

Presence of DNA antibodies in some patients on anticonvulsants may indicate that their convulsions were due to SLE.

     

Tissue specificity of antinuclear antibodies in scleroderma.

Studies of antinuclear antibodies (ANA) were carried out in 39 cases of systemic scleroderma and for comparison in 19 cases of systemic lupus erythematosus (SLE) using indirect immunofluorescence (IF) methods under standard conditions. The results on three different substrates--monkey esophagus, guinea pig lip and rat liver--are reported. In 48.7% of scleroderma cases ANA showed a substrate specificity. The highest percentage of positive results in scleroderma was obtained on monkey esophagus (97.4%) and the lowest on rat liver (61.5%). In SLE, in contrast, only about 13% of the sera displayed such specificity. If only sera with substrate specificity are considered, the positive results on monkey esophagus and rat liver are 94.7% and 21.1%, respectively. Titers of sera reacting positively on 2 or 3 substrates were mostly in agreement, although some sera both in systemic scleroderma and SLE showed higher titers on monkey esophagus. The IF pattern was usually the same regardless of the substrate. Tests for ANA in scleroderma should be performed on at least 2 substrates simultaneously.     

Quantitative determination of anti-dsDNA antibodies and antibody/dsDNA stoichiometries in prepared,soluble complement-fixing antibody/dsDNA immune complexes

We have investigated quantitatively the complement-mediated binding of prepared, soluble ¹²⁵I-7S IgG antibody/³H-dsDNA immune complexes to human red blood cells (RBCs). We have performed these studies by using a detailed modification of the RBC-CF assay [Pedersen et al., J. Immun. Meth. 38, 2692–2280 (1980)] which now allows for the simultaneous measurement of both ³H-DNA and ¹²⁵I-binding to the cells. Our results indicate that, in the case of three SLE patients, their anti-dsDNA antibody titers are sufficiently high that a small fraction of their ¹²⁵I-7S IgG antibodies (ca 0.1–0.2%) can be identified as specifically anti-dsDNA. We have also used an indirect method (with ¹²⁵I-labelled rabbit anti-human IgG) for the determination of IgG anti-dsDNA antibodies in complement-fixing antibody/dsDNA immune complexes that bind to RBCs, and the results of these measurements are in reasonable agreement with the direct binding experiments. These studies have also allowed us to estimate the antibody/DNA stoichiometries in complement-fixing immune complexes. The results of these experiments may provide a useful standard for the analysis of monoclonal anti-dsDNA antibodies.     

Production and analysis of IgG monoclonal anti-DNA antibodies from systemic lupus erythematosus (SLE) patients.

This study compares recently devised methods for producing IgG anti-DNA MoAbs from patients with SLE and analyses the antibodies generated from one patient at different phases of disease. Lymphocytes from SLE patients were transformed with Epstein-Barr virus(EBV) and/or fused with a heteromyeloma cell line, CB-F7. Direct fusion with CB-F7 resulted in the highest proportion of IgG-secreting lines, whereas EBV transformation resulted in a high percentage of IgM-secreting lines. Using direct fusion, five IgM anti-DNA antibody-secreting hybridomas were generated using lymphocytes from a patient with relatively inactive SLE. Six months later when the disease was active, only IgG anti-DNA antibodies were produced. The antigen-binding patterns of the MoAbs were analysed. Only one of the IgM anti-DNA antibodies reacted with dsDNA by ELISA and none by Crithidia immunofluorescence, whereas two of the IgG antibodies reacted with dsDNA by ELISA and Crithidia but did not bind to ssDNA. Only the two IgG high affinity anti-dsDNA antibodies bound to histones, and this was enhanced by added DNA, whereas three IgM antibodies bound to cardiolipin. This study supports the notion that MoAbs derived from a patient with SLE represent those found in the serum of SLE patients at different stages of disease activity. The binding to histones by the two IgG anti-dsDNA antibodies supports the recently expressed view that antibodies binding DNA/histone may be important in the pathogenesis of SLE.     

The fine specificity of IgG antiguanosine antibodies in systemic lupus erythematosus

The antigen specificity, isotype, and subclass of antinuclear antibodies may be related to their pathogenicity in systemic lupus erythematosus (SLE). Our laboratory found that IgG antibodies that bound the nucleoside, guanosine, occurred frequently in SLE patients. In contrast, sera from healthy subjects contained IgM but not IgG antiguanosine antibodies. The present studies were designed to characterized the fine specificity of IgG antiguanosine antibodies in SLE and compare them with IgM antiguanosine antibodies in normal sera. Serum antinuclear antibodies from six healthy subjects and six SLE patients were isolated by affinity binding to guanosine and measured by an enzyme-linked immunosorbent assay (ELISA). IgM in normal sera, and both IgM and IgG in SLE sera bound guanosine. IgM antiguanosine antibodies in normal sera were polyspecific and bound other nucleosides and 1-methylguanosine but not denatured DNA (ssDNA). In contrast, IgG antiguanosine antibodies from the SLE patients bound guanosine and ssDNA but not other nucleosides or 1-methylguanosine. SLE IgM antiguanosine antibodies had the same fine specificity and bound guanosine and ssDNA but not any of the other nucleosides. These results suggest that SLE IgG and IgM antiguanosine antibodies have fine specificity in contrast to the polyspecific IgM antibodies in normal sera. In addition, subclass analysis indicated that all SLE patients had either IgG1 or IgG3 subclass of antiguanosine antibodies that bind complement. Characterizing the isotype, subclass, and fine antigen specificity of antiguanosine antibodies should assist in evaluating their potential pathogenicity in SLE.     

Systemic lupus erythematosus sera antilymphocyte reactivity: detection of antibodies to Tac-antigen positive T cell lines.

Sera obtained from patients with systemic lupus erythematosus (SLE) were tested for their reactivity to cell lines derived from cutaneous T-cell lymphoma (CTCL), or adult T cell leukaemia (ATL), and with other cell lines, by indirect immunofluorescence method. Approximately one half of SLE sera reacted with the surface antigens of HUT-102 cells, a cell line from CTCL, which constitutively expresses Tac antigen. The titre tended to be higher in the active than in the inactive stage. These positive sera also reacted with other neoplastic or normal T cell lines having Tac antigen. SLE sera reacting with HUT-102 surface antigens were further examined for their reactivities to Tac antigen, the putative IL-2 receptor, using HUT-102 or ATL-2. Pretreatment with anti-Tac monoclonal antibody partially blocked the reactivities to HUT-102 surface antigens in nine of 15 SLE sera tested. The binding of 125I-labelled anti-Tac monoclonal antibody was displaced by the addition of sera from six of 15 SLE patients. In addition, nine of the 15 SLE sera could inhibit the binding of 125I-labelled IL-2 to ATL-2 cells. These results suggested that some of SLE sera contained antibodies against the IL-2 receptor.     

Comparison of chemiluminescence microparticle immunoassay,indirect immunofluorescence assay,linear immunoassay and multiple microbead immunoassay detecting autoantibodies in systemic lupus erythematosus

The aim of study was to detect antinuclear antibodies (ANA) using indirect immunofluorescence assay (IIFA), linear immunoassay (LIA), chemiluminescence microparticle immunoassay (CMIA), multiple microbead immunoassay (MBI) and to compare these four methods in the performance of diagnosing systemic lupus erythematosus (SLE). Serum ANA were detected in 147 SLE cases and 42 healthy controls (HCs). The sensitivity, specificity, accuracy, positive predictive value and agreement, the area under the curve of four methods in diagnosing were calculated. Finally, a diagnostic model through logistic regression was constructed. The sensitivity of CMIA and IIFA in diagnosing SLE was 89.08% and 89.12%, higher than other two methods (P < .01), while highest specificity lied in CMIA (95.24%) and LIA (95.24%). The accuracy was highest in CMIA (91.01%), and lowest in LIA (83.07%). CMIA and the other three methods had good agreement, especially with LIA (κ = .798, 95% CI, 0.708-0.88). ANA-IIFA (OR = 1.016, P < .001) and anti-SSA antibodies (OR = 1.017, P = .043) were finally included in the SLE diagnostic model, with AUC value of 0.964 (95% CI, 0.936-0.991). SLE patients exhibited 14 various ANA patterns, especially AC-1, AC-4, and AC-5. Antibodies against SSA and dsDNA were mostly seen with AC-1 and AC-4 patterns, while antibodies against RNP, Sm, SSA, dsDNA, nucleosome and PO were most frequently observed with AC-5 pattern in SLE. CMIA method is a reliable screening test for detections of antibodies related to SLE. Using ANA-IIFA and anti-SSA antibodies by CMIA can discriminate SLE patients from HCs effectively.     

A semi-automated microassay method for the measurement of ablastin,a division inhibitory antibody

Division of Trypanosoma lewisi in the rat is terminated by ablastin, a factor(s) in the serum of rats acquired during infection which is believed to be specific antibody. In this study a semi-automated microassay technique for the measurement of ablastin is described. The system involved the use of [³H]TdR as a marker for trypanosome division and a multiple-well cell harvester tr harvest trypanosomes from wells of microtitre plates. The method is versatile, quantitative and easy to perform, permitting the simultaneous measurement of numerous samples for this division-inhibitory activity.