The mucin carbohydrate epitope sialyl-Le", detected with the mono clonal antibody AM-3, is strongly overexpressed in >90% of human colon carcinomas. We show here that in colon carcinoma one of the mucin cores bearing the sialyl-Le* group is MUC-1, whereas sialyl-Le" present in normal colon is not detectable on MUC-1. The amounts of MUC-1 core detectable with the monoclonal antibody BC3 in extracts of tumor tissue are 60—180%of those in normal tissue. Two other carbohydrate epitopes located on MUC-1 in mucins from normal and tumor tissue have also been characterized. In contrast to sialyl-Le*, their expression on MUC-1 is variable and does not correlate with the malignant transformation of colonie mucosa. The transfer of the sialyl-Lex group onto the MUC-1 core contributes to the colon carcinoma-associated overexpression of the sialylLex epitope.

ABSTRACT A novel commercially available enzyme-linked immunosorbent assay (ELISA) for prevaccination screening and diagnosis of Q fever (PanBio Coxiella burnetii immunoglobulin G [IgG] ELISA) was compared to the complement fixation test (CFT), and the indirect fluorescent-antibody test (IFAT) was used to resolve discrepant results between the other two tests. A total of 214 serum samples was tested. The ELISA demonstrated a specificity of 96% (46 of 48 samples) and a sensitivity of 71% (95 of 134 samples). Of the six serum pairs showing CFT seroconversion, three pairs showed a corresponding ELISA seroconversion. No cross-reactivity was observed in the ELISA with serum samples from patients with mycoplasma, brucella, and chlamydia infections. One of the 13 patients with leptospirosis demonstrated a positive result in the ELISA but not in the CFT or the IFAT, and Legionella pneumophila serogroup 4 antibody was found in one of the two sera that were false-positive by ELISA. The results presented in this study suggest that the PanBio Q fever IgG ELISA is a specific alternative method for prevaccination testing and an aid for the diagnosis of Q fever. This test is suitable for use as a screening assay, with CFT and/or IFAT used to confirm negative results.

We compared the performance of 2 commercially available dipstick assays, 2 enzyme-linked immunosorbent assays (ELISAs), and an indirect immunofluorescent antibody (IFA) assay for the diagnosis of scrub typhus, using the indirect immunoperoxidase (IIP) test as the reference standard. The dipstick assays were the Integrated Diagnostics (Baltimore, MD) Dip-S-Ticks Scrub Recombinant (r56) dipstick test (INDX assay) and the PanBio (Brisbane, Australia) Scrub Typhus IgM and IgG Rapid Immunochromatographic test (PanBio assay). One of the ELISAs used pooled cell lysates of Karp, Kato, and Gilliam strain Orientia tsutsugamushi as antigen (pooled-antigen ELISA), and the other used a recombinant r56 protein as the antigen (recombinant ELISA). With a panel of 123 positive and 227 negative sera, sensitivity and specificity of the assays were as follows: INDX assay, IgG, 60% and 95%, IgM, 60% and 97%; PanBio assay, IgG, 94% and 96%, IgM, 83% and 93%; IFA (1:400 cutoff), IgG, 91% and 96%, IgM, 85% and 98%; pooled-antigen ELISA, IgG (1:1600 cutoff), 97% and 89%, IgM (1:400 cutoff), 94% and 91%; recombinant ELISA, IgG (1:1600 cutoff), 97% and 92%, IgM (1:400 cutoff), 93% and 94%. Because of its excellent performance and use of a standardized, commercially available antigen, the recombinant ELISA is suitable for use in a diagnostic laboratory, where it may be able to replace the IFA and IIP assays. In contrast, the PanBio dipstick assay was easy to perform and did not require sophisticated equipment, making it suitable for use in rural areas where more sophisticated diagnostic tests such as the ELISA and IFA may not be available.

ABSTRACT The variable 56-kDa major outer membrane protein of Orientia tsutsugamushi is the immunodominant antigen in human scrub typhus infections. We developed a rapid immunochromatographic flow assay (RFA) for the detection of immunoglobulin M (IgM) and IgG antibodies to O. tsutsugamushi . The RFA employs a truncated recombinant 56-kDa protein from the Karp strain as the antigen. The performance of the RFA was evaluated with a panel of 321 sera (serial bleedings of 85 individuals suspected of scrub typhus) which were collected in the Pescadore Islands, Taiwan, from 1976 to 1977. Among these 85 individuals, IgM tests were negative for 7 cases by both RFA and indirect fluorescence assay (IFA) using Karp whole-cell antigen. In 29 cases specific responses were detected by the RFA earlier than by IFA, 44 cases had the same detection time, and 5 cases were detected earlier by IFA than by RFA. For IgG responses, 4 individuals were negative with both methods, 37 cases exhibited earlier detection by RFA than IFA, 42 cases were detected at the same time, and 2 cases were detected earlier by IFA than by RFA. The sensitivities of RFA detection of antibody in sera from confirmed cases were 74 and 86% for IgM and IgG, respectively. When IgM and IgG results were combined, the sensitivity was 89%. A panel of 78 individual sera collected from patients with no evidence of scrub typhus was used to evaluate the specificity of the RFA. The specificities of the RFA were 99% for IgM and 97% for IgG. The sensitivities of IFA were 53 and 73% for IgM and IgG, respectively, and were 78% when the results of IgM and IgG were combined. The RFA test was significantly better than the IFA test for the early detection of antibody to scrub typhus in primary infections, while both tests were equally sensitive with reinfected individuals.

ABSTRACT An immunochromatographic test that incorporates recombinant antigens (Dengue Duo Rapid Strip Test; PanBio, Brisbane, Australia) has recently become commercially available. This assay is performed in 15 min and detects both immunoglobulin M (IgM) and IgG in a capture format. The four recombinant proteins used represent the N-terminal 80% of the viral envelope glycoproteins of dengue viruses 1, 2, 3, and 4, respectively. The sensitivity and specificity of the recombinant-antigen-based assay were 90 and 86%, respectively. The similar diagnostic performance of these antigens to that of enzyme-linked immunosorbent assays using whole dengue virus suggests that they mimic whole dengue viruses in primary structure and epitope conformation. These results suggest that recombinant proteins can be used in diagnostic assays for dengue to overcome safety issues associated with the use of whole virus.

ABSTRACT The 56-kDa major outer membrane protein antigen of Orientia tsutsugamuchi is the immunodominant antigen in human scrub typhus (ST) infections. An enzyme-linked immunosorbent assay (ELISA) using a recombinant 56-kDa protein (r56) to detect specific immunoglobulin M (IgM) produced in ST infections was developed, and its performance was evaluated using sera from patients with active ST (n = 59), spotted fever (SF) (n = 31), and murine typhus (MT) (n = 6) and from those without rickettsial infection (n = 52). The r56 ELISA was compared to an ELISA using native whole cell lysate ofO. tsutsugamushi Karp or O. tsutsugamushiGilliam as antigens. The performance of the assays using r56 was similar to that of those using native antigens. Using indirect immunoperoxidase (IIP) as the reference test, sensitivities were 86, 88, and 88% while specificities were 84, 90, and 87% in the three assays. Furthermore, cross-reactivity in confirmed cases of SF and MT was low (5.4, 2.7, and 2.7% respectively). The additional use of IgG in the r56 ELISA gave improved performance (sensitivity, 80%; specificity, 96%; cross-reactivity in SF and MT, 2.7%). The detection of high levels of IgG in some IgM-negative patients illustrates the importance of including a test for IgG in the detection of secondary or reactivated infections, since many of these patients were from regions in Thailand where these infections are endemic.

ABSTRACT A commercially available enzyme-linked immunosorbent assay (ELISA) (PanBio Dengue Screening ELISA) that utilized both immunoglobulin M (IgM) and IgG capture in the same microtiter well for the diagnosis of dengue infection was evaluated. Sensitivity in primary and secondary dengue was 95%, while specificity was 94%.

ABSTRACT A commercially available enzyme-linked immunosorbent assay (ELISA) for the diagnosis of Q fever (PanBio Coxiella burnetii immunoglobulin M [IgM] ELISA, QFM-200) was compared to the indirect fluorescent antibody test (IFAT) for C. burnetii IgM and the complement fixation test (CFT). The ELISA demonstrated 92% agreement with the reference method (IFAT), and gave a sensitivity of 99% (69 of 70 samples) and a specificity of 88% (106 of 121). Specificity can be increased with confirmation by IFAT. CFT was found to have a specificity of 90% (107 of 119), although it was lacking in sensitivity (73%; 51 of 70). No cross-reactivity was observed in the ELISA with serum samples from patients with mycoplasma ( n = 6), chlamydia ( n = 5), or legionella ( n = 4) infections, although 2 of 5 patients with leptospirosis and 1 of 4 samples containing rheumatoid factor (RF) demonstrated positive results in the ELISA. Results indicate that the performance of the PanBio C. burnetii (Q fever) IgM ELISA ( F = 187) is superior to that of CFT ( F = 163), and consequently the ELISA should be a useful aid in the diagnosis of acute Q fever.

A commercially available whole‐cell pertussis IgG ELISA was used to test the response of 137 2‐month‐old infants to immunization with a trivalent acellular pertussis vaccine. The pre‐immunization geometric mean (GM) IgG index was 6.96 (95% confidence interval (CI) 5.88–8.04) and the postimmunization GM index was 13.16 (95% CI 12.20–14.11), P < 0.001. Eighty percent of subjects (110/137) had a significant 1.5‐fold increase of pertussis IgG index (97/137, 71%) or a postimmunization IgG index > 10 (93/137, 68%). In single antigen ELISA, 83% showed at least a fourfold increase in pertussis toxin‐specific IgG (PT‐IgG) and 91% showed an increase in IgG specific for filamentous haemagglutinin (FHA‐IgG). Four percent had high pre‐ immunization antibody levels (index > 20), likely to reflect recent maternal exposure to pertussis. This correlated with a smaller increase in pertussis IgG index. A decline in pertussis IgG index postimmunization occurred in 17/24 infants (71%) whose pre‐immunization IgG index was > 10. This postimmunization pertussis IgG index was not significantly different to that of infants with a low pre‐immunization index. A similar trend was noted with PT‐IgG and FHA‐IgG results. The whole‐cell ELISA can detect a response to acellular pertussis vaccination in most infants if both antibody index and degree of seroconversion are calculated and at least one criterion is satisfied.

ABSTRACT An immunochromatographic test for the rapid determination of immunoglobulin M (IgM) and IgG antibodies to Burkholderia pseudomallei was evaluated by using sera from bacteriologically confirmed melioidosis patients and high-risk and clinically suspected patients, along with disease control groups. The sensitivities were 100 and 93% for the IgG and IgM tests, respectively, while the specificity was 95% for both assays. The test was rapid and simple to perform, with results obtained in 10 min.

BACKGROUND:A number of commercial ELISA for dengue diagnosis have recently become available, though direct comparison between these assays have not been published.OBJECTIVES:The Venture Technologies Dengue IgM and IgG Dot Blot assays and the PanBio Dengue Duo IgM and IgG Capture ELISA were compared.STUDY DESIGN:Paired sera from patients with dengue (n=20) and Japanese encephalitis (JE, n=10), and single sera from patients with typhoid (n=10), leptospirosis (n=10) and scrub typhus (n=10) were assayed according to the manufacturer's instructions.RESULTS:The Dot Blot IgM ELISA showed higher sensitivity than the PanBio IgM ELISA (100 vs. 95%), while the PanBio IgM ELISA showed higher specificity in JE (100 vs. 20%) and non-flavivirus infections (100 vs. 97%). Defining elevation of either IgM or IgG as a positive result, the Dot Blot and ELISA tests both showed 100% sensitivity in dengue infection, while the PanBio test showed superior specificity in JE (70 vs. 0%) and non-flavivirus infections (100 vs. 67%).CONCLUSIONS:Both assays are useful aids to the serological diagnosis of dengue infection. The clinical setting, user preference and local conditions will be important in determining which test is more appropriate.

A commercial capture ELISA for specific IgM and IgG antibodies produced during dengue infection (PanBio Dengue Duo) showed excellent sensitivity (99%, n = 78) using sera collected at hospital discharge compared with established ELISA and hemagglutination inhibition (HAI) assays. Furthermore, the ELISA was able to diagnose 79% of the dengue cases using sera collected at hospital admission. The ELISA also showed high specificity (92%) in paired sera from patients without flavivirus infection (n = 26), although 45% of the patients with Japanese encephalitis (n = 20) showed elevation of IgG but not IgM. The IgG capture ELISA showed good correlation with the HAI assay (r = 0.83, P < 0.0001), and IgG levels could be used to distinguish between primary and secondary infection, with 100% of primary infections and 96% of secondary infections being correctly classified. This ELISA should prove useful in the clinical diagnosis of dengue infections.

ABSTRACT A new commercial enzyme-linked immunosorbent assay (ELISA) for the diagnosis of Japanese encephalitis virus infections showed a sensitivity of 88% with sera and 81% with cerebrospinal fluid and a specificity of 97% with sera from patients with primary and secondary dengue virus infections. Specificity was 100% when samples from nonflavivirus infections were tested.

ABSTRACT The performances of the MRL dengue fever virus immunoglobulin M (IgM) capture enzyme-linked immunosorbent assay (ELISA) and the PanBio Dengue Duo IgM capture and IgG capture ELISA were compared. Eighty sera from patients with dengue virus infections, 24 sera from patients with Japanese encephalitis (JE), and 78 sera from patients with nonflavivirus infections, such as malaria, typhoid, leptospirosis, and scrub typhus, were used. The MRL test showed superior sensitivity for dengue virus infections (94 versus 89%), while the PanBio test showed superior specificity for JE (79 versus 25%) and other infections (100 versus 91%). The PanBio ELISA showed better overall performance, as assessed by the sum of sensitivity and specificity ( F value). When dengue virus and nonflavivirus infections were compared, F values of 189 and 185 were obtained for the PanBio and MRL tests, respectively, while when dengue virus infections and JE were compared, F values of 168 and 119 were obtained. The results obtained with individual sera in the PanBio and MRL IgM ELISAs showed good correlation, but this analysis revealed that the cutoff value of the MRL test was set well below that of the PanBio test. Comparing the sensitivity and specificity of the tests at different cutoff values (receiver-operator analysis) revealed that the MRL and PanBio IgM ELISAs performed similarly in distinguishing dengue virus from nonflavivirus infections, although the PanBio IgM ELISA showed significantly better distinction between dengue virus infections and JE. The implications of these findings for the laboratory diagnosis of dengue are discussed.

Antibodies reactive with peptide epitopes on the core protein of MUC1 epithelial mucin have been demonstrated in some patients with adenocarcinomas. Because these epitopes can be exposed on MUC1 in the serum of healthy women, we measured concentrations of MUC1-reactive antibodies in the serum of healthy pregnant and non-pregnant women, and in patients with benign and malignant ovarian tumours. Antibodies were measured in an enzyme-linked immunosorbent assay utilising a synthetic peptide corresponding to a 105-amino-acid segment of the MUC1 tandem repeat region (5.25 repeats). MUC1-reactive antibodies were always of an IgM isotype and concentrations were highest in young healthy women and declined progressively with age (P=0.0006) concomitantly with increasing serum MUC1 levels (P=0.003). Regardless of age, antibody levels were lower in cancer patients than in healthy women (P<0.0001), but MUC1 levels were much higher in cancer patients (P<0.0001). Although high antibody levels were associated with greater survival in ovarian cancer (P=0.015), multivariate regression analysis showed that this was not a significant independent prognostic indicator after consideration of the International Federation of Gynaecology and Obstetrics (FIGO) stage, histological type, serum MUC1 levels and age. Serial measurement of MUC1 and MUC1 antibodies during treatment in 18 patients with ovarian cancer and throughout pregnancy in 10 women showed a negative correlation between alterations in MUC1 and MUC1 antibodies. These results show that MUC1-peptide-reactive antibodies are present in the serum of healthy women and women with cancer and that they probably form immune complexes with MUC1, but provide no evidence for an augmentation of the humoral immune response to MUC1 in ovarian cancer

Amiodarone is used to treat life-threatening cardiac arrhythmias. Amiodarone-induced pulmonary toxicity (APT) can be difficult to diagnose. APT may result in increased mucus production and mucin expression. Thus, serum mucin-1 was evaluated as a marker for amiodarone-induced pulmonary toxicity. Concentrations of mucin-1 in peripheral blood were determined using cancer-associated serum antigen (CASA) assay in patients taking amiodarone. Eight of ten patients who developed major amiodarone toxicity had high serum CASA levels. Patients with toxicity had a significantly higher mean rank CASA concentration compared with those without major toxicity. CASA shows potential as a marker for amiodarone-induced toxicity, particularly pulmonary toxicity.

Epstein-Barr Yirus (EBY) is the causative agent of infectious mononucleosis (1M). The virus is primarily transmitted via saliva, with seroprevalence of approximately 90% in adults (Rocchi el al., 1977; Yao etal., 1985). Primary EBY infection in infants and young children is usually asymptomatic or at least very mild. In adults, 1M is a selflimiting disease characterised by fever, pharyngitis, generalised lymphadenopathy and splenomegaly (Evans, 1976). Traditionally, the serodiagnosis of EBY infection is based on the detection of heterophile antibodies. However, at least 10% of people with acute 1M fail to produce heterophile antibody with this figure being much higher in children (Evans et al., 1975; Sumaya and Ench, 1985). A more specific method of serodiagnosis of 1M is the detection of EBY -specific antibodies that appear during primary infection. Most serodiagnostic tests are based on the detection of antibodies to the Yiral Capsid Antigen (YCA) (Weidbrauk et al., 1993; Field et al., 1995). YCA antibodies of the IgG and IgM class become detectable early in the acute phase of infection. Anti-YCA IgM levels peak about 3 weeks after the onset of clinical disease, then rapidly decline to become undetectable. In contrast, YCA IgG antibodies persist for life (Youmans et al., 1985; Nikoskelainen et al., 1975). Although the indirect immunofluorscence assay (IF A) is the standard method for detection of antiYCA antibodies, it is not without limitations. IFA is difficult to standardize, time-consuming and not convenient for large scale screening (Wiedbrauk et al., 1993). The development of enzyme-linked immunosorbent assays (ELlSAs) for specific EBY antibodies has provided a sensitive and specific method that is objective and convenient for large scale screening (Hopkins et al., 1982; Luka et al., 1984) and assays for YCA are now available commercially.

ABSTRACT Saliva was collected prospectively from patients presenting with suspected dengue infection 4 to 8 days after the onset of symptoms and assayed by a commercial dengue immunoglobulin M (IgM) and IgG capture enzyme-linked immunosorbent assay (ELISA) (PanBio Dengue Duo ELISA). Laboratory diagnosis was based on virus isolation and on hemagglutination inhibition (HAI) assay and an in-house IgM and IgG capture ELISA. With a positive result defined as either salivary IgM or IgG levels above the cutoff value, an overall sensitivity of 92% was obtained for both primary- and secondary-dengue patients (22 of 24), while no patients with non-flavivirus infections ( n = 11) and no healthy laboratory donors ( n = 17) showed elevation of salivary antidengue antibody (100% specificity). Salivary IgG levels correlated well with serum HAI titer ( r = 0.78), and salivary IgG levels could be used to distinguish between primary- and secondary-dengue virus infections.