Determinations of Soluble Fas and Soluble Fas Ligand in Patients with Systemic Lupus Erythematosus

Background :The Fas/Fas ligand (FasL) system plays an important role in apoptosis by involvement in various immunologic functions, especially the removal of autoreactive and activated T-cells. sFas is a variant of the Fas receptor molecule, which lacks the transmembrane domain by alternative splicing of Fas mRNA and has an inhibitory effect in apoptosis by inhibition of the Fas/FasL pathway. sFasL is a coverted form of FasL by metalloproteinase and is increased in various malignant and autoimmune diseases. In this study, we investigated the expression of sFas and sFasL in systemic lupus erythematosus (SLE) and evaluated their usefulness as markers of disease activity. Method :The concentration of sFas and sFasL in sera from 43 patients with SLE, 17 with rheumatoid arthritis (RA) and 15 normal healthy persons were measured using sFas (S) ELISA Kit and sFas Ligand ELISA Kit (MBL Co., LTD., Nagoya, Japan), respectively. Twenty of 43 SLE sera were paired samples of 10 patients obtained on admission and discharge. Result :The concentration of sFas in SLE (3.12±2.28 ng/mL) was significantly higher than in RA (2.23±0.37 ng/mL) and in the normal control (2.12±0.33 ng/mL). In particular, the concentration of sFas in sera on admission (4.35±3.68 ng/mL) was significantly higher than in the sera on discharge (2.89±0.66 ng/mL), but, the concentration of sFasL among the 3 groups was not statistically different. Conclusion :These results suggest that apoptosis is involved in the pathogenesis of SLE and sFas might be a useful marker as a predictor of disease activity. Further study on the correlation between sFas and other disease activity markers, such as CRP, CH50, CD4 cell count and autoantibody titer is needed. Also, the evalution of sFas as a predictor of disease progression on follow-up studies of these patients is needed.ope

Combined Treatment with Interferon Alpha and Ribavirin for Chronic Hepatitis C in Patients with Previous Non-response or Relapse to Interferon Alone

Background/Aims: Interferon-alpha has been effective in 10-20% of treated patients with chronic hepatitis C (CH-C) on a long term basis. We conducted this study to evaluate the biochemical and virological outcomes of combined treatment with interferon alpha and ribavirin for the patients who had CH-C but showed non-response or relapse to interferon alpha alone. Methods: Twenty five patients with CH-C who had not responded or relapsed to interferon alpha alone treatment were enrolled. Eighteen patients were given by the combined treatment of interferon alpha and ribavirin and 7 patients were not given any specific treatment as control. Interferon alpha-2a was given subcutaneously, at a dose of 4.5 MU thrice weekly. Ribavirin was also given orally, at a dose of 900 mg/day for 24 weeks. We quantified serum HCV-RNA levels at the end of treatment. Results: The normalization rate of serum ALT at the end of treatment was 47.1% (8/17) in treated group and 14.3% (1/7) in control group and negative conversion of HCV-RNA was noted in all patients. In the treated group, 75% (6/8) of responders at the end of treatment sustained serum ALT level normally during 24 weeks follow-up, but none has responded persistently in the control group. Conclusions The combined treatment with interferon alpha and ribavirin is effective and safe for treating chronic hepatitis C in patients who showed non-response or relapse to interferon alone.ope

Performance Evaluation of a New Automated Chemiluminescent Immunoanalyzer-Based Interferon-Gamma Releasing Assay AdvanSure I3 in Comparison With the QuantiFERON-TB Gold In-Tube Assay

BACKGROUND: The interferon-gamma (IFN-γ) releasing assay (IGRA) is widely used for latent tuberculosis infection (LTBI) diagnosis. We evaluated the analytical performance of a new automated chemiluminescent immunoanalyzer-based IGRA (CLIA-IGRA), AdvanSure I3 (LG Life Sciences, Seoul, Korea) and compared it with that of the QuantiFERON-TB Gold In-Tube (QFT-GIT) assay. METHODS: Repeatability and reproducibility were evaluated at four levels. Detection capability, including limit of blank (LoB), limit of detection (LoD), and limit of quantification (LoQ), was evaluated using IFN-γ standard material (National Institute for Biological Standards and Control code: 87/586). Agreement between the results of two assays was evaluated using 341 blood samples from healthcare workers and patients at a tertiary care hospital. To determine the cut-off value of CLIA-IGRA for diagnosing LTBI, the ROC curve was analyzed. RESULTS: Repeatability and reproducibility were 4.86-7.00% and 6.36-7.88% CV, respectively. LoB, LoD, and LoQ were 0.022, 0.077, and 0.249 IU/mL, respectively. IFN-γ values between CLIA-IGRA and QFT-GIT showed a strong correlation within the analytical measurable range of both assays, especially when the value was low. Qualitative comparison of the two assays yielded a 99.1% overall agreement (kappa coefficient=0.98). A cut-off value of 0.35 IU/mL was appropriate for diagnosing LTBI. CONCLUSIONS: CLIA-IGRA is a reliable assay for LTBI diagnosis, with performance similar to that of QFT-GIT.ope

Clinical Significance of Anti-HSP 70 Antibody in the Patients with Systemic Lupus Erythematosus

Background :Heat shock proteins (HSPs), or stress proteins, are immunodominant antigens of many microorganisms. In this study, we have detected the anti-HSP 70 antibody and tried to explain the role of the antibody with respect to the pathogenesis of SLE. Furthermore, we have attempted to find out the possibility to link the presence of the autoantibody with the monitoring and diagnosis of systemic lupus erythematosus (SLE). Method :A total of 80 samples from 55 SLE patients were screened for the presence of anti-HSP 70 antibodies. Simultaneously 59 healthy people were tested as a control group. The anti-HSP 70 antibodies were measured by enzyme-linked immunosorbent assay (ELISA) and confirmed by western blot in anti-HSP 70 antibody ELISA positive samples. The activity of disease state was confirmed by the patients’medical record and systemic lupus activity measure (SLAM). Result :The mean optical density (O.D.450) of ELISA in healthy controls and SLE patients were 0.15±0.18 (mean±S.D.) and 0.13±0.14. The correlation of SLAM Score and ELISA O.D. was r2 = 0.19, P = 0.014. And, the mean O.D. value of ELISA was 0.18±0.02 and 0.11±0.01 before and after treatment (P < 0.05). We compared samples with SLAM Score. The O.D. of anti-HSP 70 ELISA in these patients were 0.20±0.02 and 0.08±0.002 before and after treatment respectively (n=10, mean±S.D., P < 0.01). Conclusion :Anti-HSP 70 antibody was not a clinically useful diagnostic marker in SLE patients. However, the titer of anti-HSP 70 antibody can be used for the monitoring of the therapeutic effectiveness in these patients.ope

Detection of Anti-Extractable Nuclear Antigens in Patients with Systemic Rheumatic Disease via Fluorescence Enzyme Immunoassay and Its Clinical Utility

PURPOSE: Testing for autoantibodies to extractable nuclear antigens (ENAs) plays an important role in the diagnosis and management of systemic rheumatic disease. Currently, no gold standard tests are available for detecting anti-ENAs. To address this gap, we aimed to identify an assay that exhibits satisfactory diagnostic performance in the detection of five common anti-ENAs by comparing two commonly used assays, an automated fluorescent enzyme immunoassay (FEIA) and a microplate ELISA assay. MATERIALS AND METHODS: Sera from 100 patients with systemic rheumatic disease were collected and assayed with FEIA and microplate ELISA to detect anti-ENAs. Statistical analyses were performed to check the agreement rate between the two platforms using kappa coefficients. Analytical sensitivity and specificity for each assay were calculated. RESULTS: The concordance rates between ELISA and FEIA ranged from 89% for anti-RNP to 97% for anti-Scl-70, and the kappa coefficients of the two assays were in the range of 0.44 to 0.82. Between the two assays, a significant difference in sensitivity and specificity was seen only for anti-Sm and anti-RNP, respectively. CONCLUSION: In this study, FEIA and ELISA showed comparable efficiency for detecting anti-ENAs.ope

Reactivities of Commercial Antisera for HLA Typing

Background : The most common problem in HLA typing is unsatisfactory quality of the antisera, or a lack of understanding of their reactivities. Therefore, commercial antisera must be verified under the conditions applied in a particular tissue typing laboratory. Methods : We evaluated the antisera reactivities of a commercial HLA-typing tray, Lymphotype HLA-ABC 72 oriental, the lot 7220999, 7230100 (Biotest, Germany), in about 300 samples from organ transplant recipients and healthy potential donors. Results : The relatively weak antisera were those that defined A26, A33, Cw5, Cw14, B46, B58, B64 and B71 etc. Some of these antisera were not indicated as ‘weak reaction’in the test result catalogue. The reactivities of each antisera indicated as ‘extra reaction’or ‘sometimes missing’ were various. Conclusions : As for antisera reactivities, the data obtained by a laboratory itself are necessary in addition to those in the test result catalogue. These data will be helpful for the correct interpretation for laboratories using same commercial kits. (Korean J Clin Pathol 2000; 20: 510-5)ope

Clinical Usefulness of Helicobacter pylori IgG Ab Assay: Comparison of Six Commercial Kits

Background :The diagnostic significance of the serological detection of antibodies to Helicobacter pylori (H. pylori) has been reported by many investigators. But the comparison data between the various serological tilts were not established in Korea. Method :Forty nine patients with upper gastrointestinal symptoms were studied from June 1997 to September 1997 in Yonsei University College of Medicine, Severance hospital Endoscopic gastric biopsy specimens were obtained for microscopic examination of the bacteria and rapid unease test (CLO test) The sera of these patients were obtained for the serological test at the same time. The six commercial tilts (Cobas Core Ⅱ,G,A,P test IgG, PYLORAGEN, Quick Vue, BIOCARD Helicobacter pylori IgG, EZ-H. P.) for the detection H. pylori antibodies were evaluated for diagnosis and screening of H. pylori infection. Result :Sensitivities for the slut tilts were from 71% to 96%, specificities were from 24% to 71%, positive predictive values were from 68% to 81%, negative predictive values were from 60% to 80%, respectively There were statistically significant differences in four groups, between G.A.P test anti Cobas Core, G.A.P test and PYLORAGEN, Quick Vue anti Cobas Core, Quick Vue and PYLORAGEN. Conclusion :Sensitivities and specificities obtained in different studies revealed as great differences in the results with the same kits as between the results obtained with different tilts in the same study. So, the serologic method alone for the diagnosis of H. pylori infection is not recommended. But in the screening of H. pylori infection, it can be used, because sensitivities and negative predictive values are relatively high.ope

Clinical Usefulness of TrepanostikaTM, Enzyme-Linked Immunosorbent Assay for Detection of Treponema pallidum-Specific Antibody

Background :The TrepanostikaTM is an enzyme-linked immunosorbent assay (ELISA) for the qualitative determination of specific antibody (Ab) to Treponema pallidum. It is important to detect Treponenia pallidum-specific Ab to confirm syphilis in patients with positive nontreponemal result or at late latent stage/late stage. Currently various ELISA methods for Treponema pallidum-specific Ab haute been developed in addition to widely used treponemal tests such as fluorescent treponemal antibody absorption (FTA-ABS) test or Treponema pallidum hemagglutination (TPHA) test. We evaluated TrepanostikaTM, anti-treponemal ELISA test. Method :The sensitivity anti specificity of this ELISA method for detecting Treponema pallidum-specific Ab (TrepanostikaTM) were evaluated and compared with other treponemal tests such as FTA-ABS and TPHA. Result :The sensitivity and specificity of TrepanostikaTM were 55.7% and 95.8%, respectively. The concordance rate with FTA-ABS was 98.9% (283/286) and 100% (272/272) with TPHA. Conclusion :TrepanostikaTM which has similar sensitivity and specificity with FTA-ABS or TPHA could replace the well-known treponemal test such as FTA-ABS or TPHA.ope

The Usefulness of PCR and Early Antigen Immunostaining as a Rapid Identification Method of Cytomegalovirus Infection

Background :Cytomegalovirus infection is an important cause of morbidity and mortality alter organ transplantation. Thus, rapid, sensitive and specific laboratory test, such as CMV anti-genemia assay and polymerase chain reaction (PCR) is necessary to determine a patient`s risk of CMV disease and to monitor the effectiveness of antiviral therapy. We compared the results of CMV-PCR and CMV early antigen immunostaining (CMV-EA) with CMV-specific IgM antibody to evalutate clinical usefulness for the early diagnosis of CMV infection anti monitoring of antiviral therapy Method :We analyzed 170 samples submitted for CMV tests between September 1995 and April 1996 in Yonsei University College of Medicine Severance Hospital. CMV-PCR and CMV-EA were performed with buffy coat cells and detection of CMV-specific IgM antibody was performed by enzyme-linked fluorescent assay (ELFA) Result :One hundred and seventy samples of 159 patients were tested anti analyzed The concordance rate of CMV-PCR, CMV-EA anti CMV-specific IgM In the same blood sample was 753%. The total Incidence of CMV disease was 25%. The sensitivity anti specificity based on the patients clinical status of PCR were 100% and 91.6% respectively in CMV-EA immunostaining method, they were 750% and 100% respectively, And, for CMV-specific IgM antibody ELFA, the sensitivity was only 500% anti the specificity was 96.4%. Conclusion :CMV-PCR and CMV-EA immunostaining are reliable methods as rapid early detection of CMV infection. The sensitivity and specificity are very high comparing to CMV-specific IgM antibody. It could also be concluded that they haute advantages not only for early diagnosis but also monitoring or follow-up of a therapeutic course as quantitative assays.ope