[Comparison of the CMV antigenemia test and CMV-DNA PCR results in solid organ transplant recipients]. / Solid organ nakli alicilarinda CMV antijenemi testi ve CMV-DNA PCR sonuçlarinin karsilastirilmasi.

Cytomegalovirus (CMV) infection is among the most common important viral infections in solid organ transplant (SOT) recipients. Diagnostic tests for detecting CMV replication are widely used for this group of patients, however there is no clear agreement on the cut-off levels for interpretation of clinical decisions especially when the low level of viral load is detected. In this study, CMV pp65 antigenemia test results were compared with plasma CMV-DNA levels detected by quantitative real-time polymerase chain reaction (qPCR) in samples of kidney and liver transplant recipients in the Central Laboratory of Dokuz Eylul University Hospital between 2011 and 2013, and the correlation between these two tests and viral load equivalent to antigenemia positivity were determined. In the study, pp65 antigenemia and CMV-DNA qPCR results were evaluated retrospectively. The samples from the same patients were included if the time between antigenemia and CMV-DNA qPCR tests were less than 48 hours. SPSS v15.0 was used for correlation, regression and ROC curve analysis. The results of the 217 samples collected from 100 patients (59 male, 41 female; age range: 16-71, mean age: 46 ± 13 years), 36 liver and 64 kidney recipients were evaluated in the study. Of the patients 80% were CMV IgM negative, IgG positive; 1% was CMV IgG and IgM positive; 2% were CMV IgM and IgG negative, while for 17 patients serological results could not be reached. CMV pp65 antigenemia and CMV-DNA were both negative in 102 (47%) samples, while both were positive in 37 (17%) samples. The single sample from a case with CMV IgM and IgG positivity yielded negative results for both antigenemia and CMV-DNA tests. In 78 samples antigenemia were negative and CMV-DNA qPCR were positive, while there were no samples with antigenemia positive and qPCR negative. Mean values of antigenemia and qPCR tests were 23 positive cells/200.000 leukocytes (range: 1 to 230 positive cells) and 12.595 copies/ml (range: 180 to 106.311 copies/ml), respectively. There was a significant correlation between antigenemia and qPCR results among the samples that were positive by both assays (r= 0.785). ROC curve analysis showed that CMV viral load of 205 copies/ml in plasma corresponds to ≥ 1 pp65 antigen positive cells per 200.000 leukocytes (sensitivity: 91.7%, specificity: 90.3%). Higher analytical sensitivity of qPCR test can be explained by the results of CMV-DNA PCR positive and antigenemia negative samples. Non-existence of samples with antigen positive and PCR negative results supported this finding. ROC analysis showed that any sample with CMV-DNA qPCR result less than 205 copies/ml, could be accepted as pp65 antigenemia negative. This viral load value is valid only for the studied patient group and assays, therefore could be changed according to study population and tests.

[Evaluation of a syphilis testing algorithm using a treponemal test for screening]. / Taramada Treponemal Test Kullanan Bir Sifiliz Tani Algoritmasinin Degerlendirilmesi.

Traditional testing algorithm for syphilis is initial screening with nontreponemal tests, then retesting positive samples for confirmation using a specific treponemal test. Commercial treponemal tests those are more sensitive than nontreponemal tests and suitable for automation are now commercially available to screen syphilis. Although the treponemal tests are offered as the first choice for syphilis screening by some of the guidelines, to date there is no consensus on recommendations in guidelines for followup testing. As some of the guidelines recommend to perform a nontreponemal test for persons with a positive treponemal screening test, the others recommend to confirm the result by another treponemal test. In this study, a testing algorithm using treponemal chemiluminescence microparticle enzyme immunoassay (CMIA; Architect Syphilis TP; Abbott Japan Co, Japan) for primary screening were retrospectively evaluated by reviewing laboratory data. A total of 12.195 serum samples obtained from 10.878 patients (7104 of them were female) who were screened by means of syphilis, between January 2007-February 2010 period have been included to the study. According to this algorithm, no further test was performed for CMIA negative samples. Samples positive by CMIA were retested by RPR (Rapid Plasma Reagin; Omega Diagnostics, UK) test. The test results of both CMIA and RPR positive samples were reported, while positive CMIA results were confirmed by TPHA (Treponema pallidum hemagglutination; Omega Diagnostics, UK) if any discrepancy in the results were identified. Screen test revealed positive results in 1.1% (120/10.878) of the patients and 2% (206/12.195) of the samples. In this study, quantitative values (sample/cut-off absorbance ratio; s/co) of positive CMIA samples were also compared with TPHA and RPR test results. It was observed that while 19.1% of CMIA positive samples with s/co ratios less than 12 were confirmed by TPHA, the confirmation rate was 100% with s/co ratios above 12. Additionally, RPR positive samples with a titer of ≥ 1/32 yielded CMIA s/co ratios above 21. As low s/co levels detected with CMIA may lead to false-positive results for syphilis, it was concluded that CMIA positive results should be confirmed by another treponemal test before RPR testing. A new syphilis testing algorithm in accordance with the results of this review and recommendations in new guidelines were established in the light of this study.