We compared the performance of four assays for the detection of cryptococcal antigen in serum samples (n ‫؍‬ 634) and cerebrospinal fluid (CSF) samples (n ‫؍‬ 51). Compared to latex agglutination, the sensitivity and specificity of the Premier enzyme immunoassay (EIA), Alpha CrAg EIA, and CrAg lateral flow assay (LFA) were 55.6 and 100%, 100 and 99.7%, and 100 and 99.8%, respectively, from serum samples. There was 100% agreement among the four tests for CSF samples, with 18 samples testing positive by each of the assays.

Conventional methods for the detection of Epstein-Barr virus (EBV)-specific antibodies include the immunofluorescence assay (IFA) and enzyme immunoassay (EIA). While sensitive and specific, these methods are labor-intensive and require separate assays for each analyte. This study evaluated the performance of a multiplex bead assay (BioPlex 2200; Bio-Rad Laboratories, Hercules, CA) for the simultaneous detection of immunoglobulin G (IgG) and IgM class antibodies to the EBV viral capsid antigen (VCA) and IgG class antibodies to Epstein-Barr virus nuclear antigen-1 (EBNA-1). Serum specimens (n ‫؍‬ 1,315) submitted for routine EBV-specific antibody testing by EIA (Grifols-Quest, Inc., Miami, FL) were also tested by the multiplex bead assay using the BioPlex 2200 automated analyzer. Specimens showing discordant results were tested by IFA. Following IFA resolution, the BioPlex VCA IgM, VCA IgG, and EBNA-1 IgG assays demonstrated 97.9%, 91.4%, and 96.9% agreement, respectively, with the results obtained by EIA. Furthermore, the BioPlex assays showed an overall agreement of 94.1% with the EIA when the specimens were categorized by disease state (susceptible, acute, or past infection) based on the EBV-specific antibody profiles. These findings indicate that the BioPlex EBV assays demonstrate a performance comparable to that of the conventional EIA, while allowing for a more rapid (2.3 h for 100 samples versus 4.5 h by the EIA) and higher-throughput (ϳ400 samples per 9 h versus 200 samples by the EIA) analysis of the EBV-specific antibody response. Epstein-Barr virus (EBV) is the primary agent of infectious mononucleosis (IM), a common syndrome characterized by fever, pharyngitis, and lymphadenopathy. Most individuals become infected during childhood, and it is estimated that nearly 95% of the adult population worldwide is seropositive for the virus (20). While the majority of infections result in either asymptomatic or mild disease, serious complications, including B-and T-cell lymphomas, nasopharyngeal carcinoma, and central nervous system involvement, may occur, especially in immunocompromised hosts (14).The diagnosis of IM is made, in most cases, on the basis of characteristic clinical manifestations or the detection of heterophile antibodies (24). However, a determination of the EBVspecific antibody response may be required for young children (especially those Ͻ4 years old) (26) and for adults suspected of having heterophile-negative IM. Testing for immunoglobulin M (IgM) and IgG class antibodies to the viral capsid antigen (VCA) and for IgG class antibodies to Epstein-Barr virus nuclear antigen-1 (EBNA-1) allows for a discrimination between recent and remote infection (8,18,21,22). Levels of antibodies (IgM and/or IgG) to VCA are typically elevated during the acute phase of IM (19,22,26), with anti-VCA IgM levels showing a steady decline 4 to 6 weeks after symptom onset (16). In contrast, anti-VCA IgG persists indefinitely, and its detection along with that of anti-EBNA-1 IgG suggests past exposure to the virus (25)...

The diagnosis of Lyme borreliosis (LB) is commonly made by serologic testing with Western blot (WB) analysis serving as an important supplemental assay. Although specific, the interpretation of WBs for diagnosis of LB (i.e., Lyme WBs) is subjective, with considerable variability in results. In addition, the processing, reading, and interpretation of Lyme WBs are laborious and time-consuming procedures. With the need for rapid processing and more objective interpretation of Lyme WBs, we evaluated the performances of two automated interpretive systems, TrinBlot/BLOTrix (Trinity Biotech, Carlsbad, CA) and BeeBlot/ViraScan (Viramed Biotech AG, Munich, Germany), using 518 serum specimens submitted to our laboratory for Lyme WB analysis. (7), confirming that the disease continues to represent a significant public health threat. The clinical manifestations of early localized disease range from nonspecific sequelae, including malaise, myalgia, and lymphadenopathy, to more characteristic findings, such as erythema migrans (EM). In the absence of appropriate therapy, disease progression may lead to significant complications, including rheumatologic, neurologic, or cardiac manifestations (15, 16).The diagnosis of Lyme borreliosis (LB) can be made clinically when patients from regions where the disease is endemic present with EM (5, 8, 18). However, in patients without EM but with objective clinical findings suggestive of disseminated LB, serologic testing is an important diagnostic approach. Appropriate serologic testing should follow the two-tier algorithm recommended by the CDC (6), consisting of initial testing with a sensitive screening assay (e.g., enzyme immunoassay) with positive or equivocal specimens to be tested by Western blot (WB) analysis. Current CDC criteria for WB interpretation recommend that Ն2 bands on the immunoglobulin M (IgM) WB or Ն5 bands on the IgG WB be present for the immunoblot to be considered positive (6, 9). Although WB is considered to be highly specific, current testing protocols in most clinical laboratories rely on visual reading and interpretation of WB strips. These procedures require the laboratory technologist to visually compare band intensities on the patient strip to those of a weakly reactive control. This approach is laborintensive, time-consuming, and subjective, allowing for potential intra-and interlaboratory variation in WB reading and interpretation. Previous studies analyzing the performance of LB serologic tests among testing laboratories have demonstrated significant variation in results, even for more objective methods, such as enzyme immunoassay (2, 3, 10). Therefore, given the inherent subjectivity in reading and interpreting WBs for diagnosis of LB (i.e., Lyme WBs), one would expect to observe significant variation in WB results, with potentially adverse effects on the laboratory diagnosis of Lyme disease and subsequent patient management decisions. Due to the need for more objective and consistent interpretation of Lyme WBs, we undertook a study to evaluate and comp...

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