Clinical and analytical relevance of NNRTIs minority mutations on viral failure in HIV-1 infected patients.

The objective of this study was to assess the analytical and clinical relevance of minority variants using a new pyrosequencing (PSQ) assay and to detect minor variants with frequencies below the current 20% clinical setting limit. A PSQ approach for detecting and quantifying mutations was developed for the analysis of 14 codons of the human immunodeficiency virus (HIV) reverse transcriptase (RT) gene below the limit of conventional sequencing. Ten patients who experienced virological failure (VF) after a first-line regimen of lamivudine, tenofovir, and either efavirenz, nevirapine, or etravirine, as well as 10 controls patients without VF, were included in this retrospective study. Baseline plasma and plasma from the time of VF were assessed using Sanger sequencing and PSQ methods. The analytical sensitivity for the detection of minor sequence variants is 5%. At baseline, no minority variant was detected in 10/10 patient controls using both the Sanger sequencing and PSQ assays, whereas, two patients who failed therapy had baseline non-nucleoside reverse transcriptase inhibitor (NNRTI) mutations that were not detected by the standard genotyping. At the time of VF, standard genotyping detected mutations in four out of the 10 VF patients, whereas, PSQ detected mutations in five out of the 10 VF patients. Clinically, minority mutations at a 10% level of detection can be assessed efficiently by pyrosequencing and used as a suitable predictor of the evolution of viral populations. These traits allow for a better interpretation of data analysis, which can help clinicians in providing a suitable treatment for HIV.

Comparison of the performance of carcinogenic HPV typing of the Roche Linear Array and Qiagen LiquiChip® HPV assays.

BACKGROUND: Cervical cancer is caused by high-risk types of human papillomavirus (HPV). DNA testing of such high-risk types of HPV could improve cervical screening.The aim of the study was to compare the sensitivities and positive predictive values of two commercially available typing assays (Qiagen LQ and Roche LA) and to comparatively assess the distribution of HPV types with these two assays. METHODS: The study population comprised 311 ASCUS + women with abnormal pap tests who were HCII positive and who were admitted to three European referral gynecology clinics between 2007 and 2010 (Madrid, Marseille and Milan). All patients underwent LQ and LA tests. RESULTS: The sensitivity of the two assays for HPV typing was 94% for LQ and 99% for LA (compared with HCII). The overall concordance between LQ and LA was 93%. The three prevalent genotypes, HPV16, HPV18, and HPV31, were identified with a high concordance using the two assays: kappa 0.93, 0.83, and 0.91, respectively. Mixed genotypes were more frequently detected by LA than by LQ: 52% vs. 18%, respectively (p < .0001). CONCLUSIONS: These assays have a good clinical sensitivity for detecting HPV types in CIN2+ patients and allow the virus type to be detected in the same experiment. Our study revealed no significant difference between LQ and LA for CIN2+ or CIN3+ diagnosis, indicating similar distributions of HPV types and a mixed genotype detection that is higher for LA than for LQ.

Dried blood spot sampling for hepatitis B virus serology and molecular testing.

BACKGROUND AIMS: Dried blood spots (DBS) on filter paper have been successfully used to diagnose and monitor several infectious diseases. The aim was to investigate the performance of DBS in hepatitis B virus (HBV) diagnosis using commercial tests in comparison to standard methods. METHODS: Paired DBS and plasma samples were collected from 200 patients: 100 patients with HBsAg negative status and 100 patients with HBsAg positive status. In the latter patient, HBeAg reactivity was tested. Ten samples of anti-HBs were collected from people vaccinated against HBV. We also studied 50 patients with positive HBV DNA viral load in plasma and 10 HBV DNA negative patients. HBV genotypes and gene polymerase mutations were determined in 10 randomly selected HBV-infected patients. The DBS sample consisted of 50 µL of whole blood, i.e. a 12-mm paper card. RESULTS: The sensitivity thresholds of HBsAg and anti-HBs antibody were 0.30 ± 0.08 IU/mL and 18.11 ± 6.05 IU/mL, respectively, for DBS with 98% sensitivity and 100% specificity. Sensitivity was 98% and specificity 100% for the detection of HBV DNA on a blotter, considering an HBV DNA threshold of 914.1 ± 157.8 IU/ml. Ten patients had an HBeAg positive status in plasma, all were detected positive using DBS. HBV genotyping and mutation detection were successfully performed on DBS, with full concordance between the 10 paired DBS and plasma samples. CONCLUSION: This study shows DBS is a reliable alternative to plasma specimens for quantifying and detecting HBsAg, anti-HBs, HBeAg and genotyping. DBS may increase the opportunities for HBV testing and treatment follow-up in hard-to-reach individuals.

HPV genotype distribution according to severity of cervical neoplasia using the Digene HPV genotyping LQ test.

A new genotyping-based DNA assay (Digene LQ(®)) was developed recently. The primary aim was to assess the distribution of HPV types using this new assay in atypical squamous cells of undeterminate significance (ASCUS). The secondary aim was to correlate the HPV types with the severity of the disease. The study population comprised 376 ASCUS women. The women were all Hybrid Capture II (HCII) positive and were admitted in three European referral gynecology clinics between 2007 and 2010. A colposcopy with histological examination was performed in all these patients. HPV 16 was typed in 40 % of patients, HPV 18 in 7 %, and HPV 31 in 17 %, and 18 % of patients had mixed genotypes. Patients aged over 30 more often had the HPV 16 genotype than patients aged under 30 (29 % vs. 11 %, chi-square test p < 0.001). The risk of cervical intra-epithelial neoplasia of grade 2 or more (CIN2 +) when HPV 18 positive is lower than the probability associated with HPV 16 or HPV 31: 28 % vs. 58 % and 52 %, respectively (chi-square test, p = 0.005 and p = 0.05, respectively). The Digene LQ(®), a new sequence-specific hybrid capture sample preparation, is fast and efficient and allows high-throughput genotyping of 18 HR HPV types by PCR compared to traditional non-sequence-specific sample preparation methods.

Analytical comparison of the cobas HPV Test with Hybrid Capture 2 for the detection of high-risk HPV genotypes.

Human papillomavirus (HPV) is a causal agent of cervical cancer, and persistent HPV16 or HPV18 infection carries a particularly high risk. The cobas HPV Test (cobas) provides individual HPV16/HPV18 genotyping with a simultaneous result for 12 other high-risk HPV (hrHPV) genotypes. Its analytical performance for hrHPV genotype detection was retrospectively evaluated against the digene Hybrid Capture 2 HPV DNA test (HC2), in three European centers, in 1360 cervical samples. Both HPV tests performed similarly, with no significant difference in the number of positive and negative samples identified by each test and good agreement between the tests was observed. Discordant samples were analyzed with the Linear Array HPV genotyping test. More low-risk HPV (lrHPV) genotypes were detected in HC2-positive/cobas-negative samples compared with HC2-negative/cobas-positive samples. Conversely, more hrHPV genotypes were detected in HC2-negative/cobas-positive samples compared with HC2-positive/cobas-negative samples. Eight HC2-negative/cobas-positive samples were positive for HPV16 compared with five HC2-positive/cobas-negative samples; HPV18 was detected in one HC2-negative/cobas-positive sample and one HC2-positive/cobas-negative sample. The cobas HPV Test demonstrates comparable analytical performance to the HC2 test, but with a lower rate of cross-reactivity with lrHPV genotypes, and has the advantage of simultaneously providing HPV16/HPV18 identification.

Incident HPV 51 Infection After Prophylactic Quadrivalent Human Papillomavirus (Types 6, 11, 16, and 18) L1 Virus-Like Particle Vaccine Gardasil/Silgard.

We report the case of a 19-year-old woman who received a complete vaccine program by Gardasil. After one year, Greiner HPV test revealed HPV51 positivity. This case report highlights the limits of the vaccine, and the need to have a clinical follow up of patients despite the vaccination program.

CD4+NKG2D+ T cells in Crohn's disease mediate inflammatory and cytotoxic responses through MICA interactions.

BACKGROUND & AIMS: Crohn's disease (CD) is an inflammatory bowel disease characterized by uncontrolled immune responses to bacterial flora, with excessive activation of T lymphocytes. MICA is a stress-induced major histocompatibility complex-related molecule expressed on normal intestinal epithelial cells (IECs) and recognized by the NKG2D-activating receptor on CD8(+) T cells, gammadelta T cells, and natural killer cells. We examined the role of MICA-NKG2D interactions in the activation of T lymphocytes in CD. METHODS: MICA expression was analyzed by flow cytometry on IECs isolated from patients with active inflammatory bowel disease and controls. NKG2D expression and function were analyzed on lamina propria and peripheral blood lymphocytes. RESULTS: MICA expression was significantly increased on IECs in CD, with higher expression in macroscopically involved areas. A subset of CD4(+) T cells expressing NKG2D was increased in the lamina propria from patients with CD compared with controls and patients with ulcerative colitis. CD4(+)NKG2D(+) T cells with a Th1 cytokine profile and expressing perforin were increased in the periphery and in the mucosa in CD. CD4(+)NKG2D(+) T-cell clones were functionally active through MICA-NKG2D interactions, producing interferon-gamma and killing targets expressing MICA. IECs from patients with CD had the ability to expand this subset in vitro. CD4(+)NKG2D(+) lamina propria lymphocytes from patients with CD highly expressed interleukin-15R alpha, and interleukin-15 increased NKG2D and DAP10 expression in CD4(+)NKG2D(+) T-cell clones. CONCLUSIONS: These findings highlight the role of MICA-NKG2D in the activation of a unique subset of CD4(+) T cells with inflammatory and cytotoxic properties in CD.

Distinctive NK-cell receptor repertoires sustain high-level constitutive NK-cell activation in HIV-exposed uninfected individuals.

We have previously associated high natural killer (NK)-cell activity and protection against HIV-1 infection in Vietnamese exposed uninfected intravascular drug users (EUs). Considering that activating and inhibitory signals sensed by NK-cell receptors regulate NK-cell activation, we performed phenotypic and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) transcript analyses of the NK-cell receptor (NKR) repertoire in 25 EUs, 19 HIV(+) intravenous drug users, and 26 uninfected blood donors. Although NK-cell activation was not linked to a unique NKR repertoire in EUs, various patterns consistent with NK-cell activation were detected in EUs: high KIR3DS1/KIR3DL1 ratio associated with down-regulated KIR3DL1 transcript levels, KIR2DL3(+) low-affinity receptor expansion associated to group HLA-C1 ligand in 2DS2(-)/2DL2(-) EUs, enhanced NKG2C/NKG2A ratio, and increased CD69 expression. Remarkably, EUs exhibited high constitutive degranulation activity in the absence of exogenous stimulation, as shown by the CD107a assay. Furthermore, CD161 expression was increased within the CD107a(+) NK-cell compartment. Our results suggest that in response to viral exposition, particular genetic or regulated features of the NKR repertoire of EUs contribute to their high constitutive NK-cell potential. This might allow NK cells to generate a more rapid and effective immune response to HIV-1, thereby contributing to prevention toward infection.

Tacrolimus/mycophenolate mofetil improved natural killer lymphocyte reconstitution one year after kidney transplant by reference to cyclosporine/azathioprine.

BACKGROUND: Recently introduced immunosuppressive drugs are more potent to control graft rejection, but current concerns are raised regarding their potential to increase long-term neoplastic and infectious complications. Considering the role of B, T, or natural killer (NK) lymphocyte in controlling alloreactive, anti-infectious, and antitumoral immune responses, we compared the impact of two immunosuppressive regimens on lymphocyte subsets one year following kidney transplant. METHODS: Multivariate regression analysis of variables affecting lymphocyte subset counts was retrospectively performed on 91 kidney-transplanted patients, analyzed before graft, at day 15 and 1-year postgraft. These patients were included in a randomized prospective open trial comparing tacrolimus/mycophenolate mofetil (FK/MMF) versus cyclosporine/azathioprine (CSA/Aza), both used in association with rabbit antithymocyte globulines (rATG) induction and prednisone. RESULTS: Fifteen days postgraft, severe T and NK lymphocyte depletion were observed in all patients, while B cell counts were selectively higher in the FK/MMF group as compared to before graft. One-year posttransplant, NK cell counts and NK cell cytotoxicity was significantly higher in patients receiving FK/MMF therapy, as compared to CSA/Aza. Cytomegalovirus (CMV) infection during the first year posttransplant was also associated to higher NK, CD8, and CD4CD8 T cell counts at month 12. CONCLUSIONS: In addition to its higher potential in preventing graft rejection, we show that after one year of transplant, FK/MMF better preserves NK innate immune effector cells and their cytotoxic potential. These data prompt to further evaluate the role of NK cells in relation to antiviral and tumoral surveillance of transplanted patients, which are common complications of long-term immunosuppression.

High urokinase expression contributes to the angiogenic properties of endothelial cells derived from circulating progenitors.

Endothelial progenitor cells (EPC) display a unique ability to repair vascular injury and promote neovascularization although the underlying molecular mechanisms remain poorly understood. Urokinase-type plasminogen activator (uPA) and its receptor (uPAR) play a critical role in cell migration and angiogenesis by facilitating proteolysis of extracellular matrix. The aim of the present study was to characterize the uPA/uPAR-dependent proteolytic potential of EPC outgrown from human umbilical cord blood and to analyze its contribution to their angiogenic properties in vitro. Cells derived from EPC (EPDC), presenting typical features of late outgrowth endothelial cells, were compared to mature endothelial cells, represented by human umbilical vein endothelial cells (HUVEC). Using quantitative flow cytometry, enzyme-linked immunosorbent assays and zymography, we demonstrated that EPDC displayed higher levels of uPA and uPAR. In conditioned culture media, uPA-dependent proteolytic activity was also found to be significantly increased in EPDC. This activity was paralleled by a higher secretion of pro-metalloproteinase-2 (pro-MMP-2). Inhibition of EPDC-associated uPA by monoclonal antibodies that block either uPA activity or receptor binding, significantly reduced proliferation, migration and capillary like tube formation. Moreover, tumor necrosis factor-alpha and vascular endothelial growth factor, known to be locally secreted in ischemic areas, further increased the proteolytic potential of EPDC by up-regulating uPA and uPAR expression respectively. The EPDC response to these factors was found to be more pronounced than that of HUVEC. In conclusion, these findings indicated that EPDC are characterized by high intrinsic uPA/uPAR-dependent proteolytic potential that could contribute to their invasive and angiogenic behaviour.

Expression of MHC class I receptors confers functional intraclonal heterogeneity to a reactive expansion of gammadelta T cells.

NK cell receptors for MHC class I molecules (MHC-NKR) can be expressed by T cell subsets. The restricted repertoire and phenotypic characteristics of MHC-NKR(+) T cells indicate that expression of MHC-NKR is acquired upon antigenic challenge and might promote expansion of T cells. Previous studies performed on in vitro generated alphabeta T cell clones concluded that MHC-NKR expression was not a clonal attribute. Here, we examined a massive monoclonal expansion of a non-leukemic gammadelta T cell population found in the peripheral blood of a lung-transplanted patient who suffered from a cytomegalovirus infection. Despite their monoclonality, these T cells displayed a heterogeneous and stable in vivo Ig- and lectin-like MHC-NKR phenotype. Twenty percent of the cells displayed a CD94(+)NKG2A(+) phenotype, and 10% were labeled with an anti-CD158b1/b2/j monoclonal antibody. A CD158b/j(+) gammadelta T cell clone derived in vitro from patient's peripheral blood lymphocytes was shown to express the activating form CD158j (KIR2DS2), which once cross-linked stimulated the clone cytolytic function and costimulated the TCR-induced production of cytokines, independently of the killer-activating receptor-associated protein (KARAP). In conclusion, heterogeneity of MHC-NKR expression confers a functional intraclonal diversity that may participate to induction of specific gammadelta T cell effector functions or proliferation upon pathogen challenge.

Comparative analysis of NK cell subset distribution in normal and lymphoproliferative disease of granular lymphocyte conditions.

We have characterized the heterogeneity of human blood NK cell subsets defined by expression of KIR, lectin like receptors and NK cell differentiation markers within a cohort of 51 healthy Caucasian individuals. High inter-individual variability in cell surface expression of most NK cell markers is observed. Range values defining NK cell subsets in healthy donors were further used as references to characterize 14 patients with NK-type lymphoproliferative disease of granular lymphocytes (NK-LDGL). Alterations of the KIR repertoire were noted in all NK-LDGL patients. NK cell expansions were classified as oligoclonal KIR(+) or as non-detectable KIR ((nd)KIR) using anti-KIR2DL1/2DS1, anti-KIR2DL2/2DL3/2DS2, anti-KIR3DL1 and anti-KIR2DS4 monoclonal antibodies. A major reduction in the size of the CD56(bright) NK cell subset was a constant feature of NK-LDGL. Altered distribution of CD94(+), CD161(+), and CD162R(+) NK cell subsets was also observed in NK-LDGL patients. Considering the potential role of NK cells in eliminating tumors or virus-infected cells, the reference values defined in this study should be valuable to characterize both quantitative and qualitative alterations of the NK cell repertoire in pathological conditions and to monitor NK cell reconstitution following hematopoietic transplantation.