Reliability of the Xpert HPV assay to detect high-risk human papillomavirus DNA in a colposcopy referral population.

OBJECTIVES: The Xpert HPV Assay (Xpert; Cepheid, Sunnyvale, CA) was developed for the multianalytic GeneXpert platform. METHODS: In a colposcopy referral population of 708 women living in the United States, two cervical specimens, A and B, were collected, and both were tested by the Xpert assay for high-risk human papillomavirus (hrHPV) DNA, permitting an evaluation of its test reliability. Specimen B was also tested by Hybrid Capture 2 (hc2; Qiagen, Germantown, MD) and the cobas HPV Test (cobas; Roche Molecular Systems, Pleasanton, CA). RESULTS: The κ and percent agreement for any hrHPV for the two Xpert results were 0.88 and 94.5%, respectively. There was no statistical difference in testing positive on both specimens by Xpert (P = .62). The sensitivity for detection of cervical intraepithelial neoplasia grade 2 or more severe (CIN2+) was 89.0% using specimen A and 90.4% using specimen B for Xpert, 90.4% for cobas, and 81.6% for hc2. CONCLUSIONS: The Xpert assay was sensitive and reliable for the detection of hrHPV and the identification of women with CIN2+.

Clinical evaluation of the cartridge-based GeneXpert human papillomavirus assay in women referred for colposcopy.

High-risk human papillomavirus (hrHPV) testing is now being introduced as a potential primary screening test for improved detection of cervical precancer and cancer. Current U.S. Food and Drug Administration-approved tests are batch tests that take several hours to complete. A rapid, non-batch test might permit point-of-care (POC) testing, which can facilitate same-day screen and management strategies. For a non-batch, random-access platform (GeneXpert; Cepheid, Sunnyvale, CA), a prototype hrHPV assay (Xpert) has been developed where testing for 14 hrHPV types can be completed in 1 h. In the first clinical evaluation, Xpert was compared to two validated hrHPV tests, the cobas HPV test (cobas, Roche Molecular Systems) and Hybrid Capture 2 (hc2, Qiagen), and to histologic outcomes using specimens from colposcopy referral populations at 7 clinical sites in the United States (n = 697). The sensitivity of Xpert for cervical intraepithelial neoplasia grade 2 or more severe diagnoses (CIN2+) (n = 141) was equal to that of cobas (90.8% versus 90.8%, P = 1) and greater than that of hc2 (90.8% versus 81.6%, P = 0.004). Xpert was more specific than cobas (42.6% versus 39.6%, P = 0.02) and less specific than hc2 (42.6% versus 47.7%, P < 0.001). Similar results were observed for cervical intraepithelial neoplasia grade 3 or higher (CIN3+) (n = 91). HPV16 detection by Xpert identified 41.8% of the CIN2+ specimens with a positive predictive value (PPV) of 54.6%. By comparison, HPV16 detection by cobas identified 42.6% of the CIN2+ specimens with a PPV of 55.0%. hrHPV detection by the Xpert demonstrated excellent clinical performance for identifying women with CIN2+ and CIN3+ that was comparable to that of currently available clinically validated tests.

Pregnancy loss after first trimester viability in women with sickle cell trait: a preliminary report.

BACKGROUND: Traditionally, sickle cell trait has not been associated with a higher risk of fetal death, but we noted several, which led us to assess all such pregnancies. METHODS: In this retrospective study, 131 patients with sickle cell trait were analyzed over a two-year period. The Institutional Review Board approved the collection of deidentified data. RESULTS: Subjects were African-American with an average age of 23.9 years, and average gestational age at delivery of 30.1 weeks. There were 10 (8.13%) intrauterine fetal deaths (IUFDs), and one neonatal death. Ascending amniotic fluid infection was noted in 50% and 92% meconium histocytes. All placentas had sickling in the intervillous space and the decidual vessels. CONCLUSIONS: Sickling in the decidual vessels and poor placental perfusion may play a role in pregnancy loss in excess of what has previously been reported. A cohort control study appears to be in order. NARRATIVE: Pregnant women with sickle cell trait are thought not to have increased maternal or fetal mortality/morbidity. Over a two year period, we studied 131 women with this hemoglobinopathy and found that 10.6% had intrauterine growth retardation (IUGR), 8.4% preterm premature rupture of the membranes, 8.1% intrauterine fetal demise (n = 10) at most occurring at 16 to 24 weeks, and one neonatal death. Amniotic fluid infection was noted in 50%, and meconium histocytes indicating intrauterine hypoxia were noted, as was unsuspected sickling in the placental vasculature. Based on this case series, sickle cell trait may not be as benign for the fetus as was previously thought.

Pregnancy loss after first-trimester viability in women with sickle cell trait: time for a reappraisal?

OBJECTIVE: The purpose of this study was to evaluate the obstetric outcomes and pathologic findings in women with sickle cell trait. STUDY DESIGN: In this retrospective case control study, pregnant women with sickle cell trait were studied over a 4-year period (2001-2005). The women who were delivered at > 16 weeks of gestation were compared with a cohort group of subjects with normal hemoglobin levels, and the placentas were sent for pathologic evaluation. RESULTS: A total of 180 pregnancies were studied with a like number of control patients. Subjects who had sickle cell trait demonstrated shorter average duration of pregnancy (233 +/- 45 days vs 255 +/- 34 days; P < .001) and lower birth weight (2114 +/- 1093 g vs 2672 +/- 942 g; P < .001). The rate of fetal death was significantly higher among study group patients (3.5% vs 9.7%; P = .015) when compared with the control group. Additionally, in study women, acute ascending amniotic infection and meconium histiocytosis were noted much more frequently. Sickling in the intervillous space and decidual vessels that were not associated with artifactual change was also found among patients sickle cell trait. CONCLUSION: Patients with sickle cell trait appear to be at increased risk for fetal loss compared with women with normal hemoglobin levels, and placental abnormalities may play a causal role.