EuroFlow Lymphoid Screening Tube (LST) data base for automated identification of blood lymphocyte subsets.

In recent years the volume and complexity of flow cytometry data has increased substantially. This has led to a greater number of identifiable cell populations in a single measurement. Consequently, new gating strategies and new approaches for cell population definition are required. Here we describe how the EuroFlow Lymphoid Screening Tube (LST) reference data base for peripheral blood (PB) samples was designed, constructed and validated for automated gating of the distinct lymphoid (and myeloid) subsets in PB of patients with chronic lymphoproliferative disorders (CLPD). A total of 46 healthy/reactive PB samples which fulfilled pre-defined technical requirements, were used to construct the LST-PB reference data base. In addition, another set of 92 PB samples (corresponding to 10 healthy subjects, 51 B-cell CLPD and 31 T/NK-cell CLPD patients), were used to validate the automated gating and cell-population labeling tools with the Infinicyt software. An overall high performance of the LST-PB data base was observed with a median percentage of alarmed cellular events of 0.8% in 10 healthy donor samples and of 44.4% in CLPD data files containing 49.8% (range: 1.3-96%) tumor cells. The higher percent of alarmed cellular events in every CLPD sample was due to aberrant phenotypes (75.6% cases) and/or to abnormally increased cell counts (86.6% samples). All 18 (22%) data files that only displayed numerical alterations, corresponded to T/NK-cell CLPD cases which showed a lower incidence of aberrant phenotypes (41%) vs B-cell CLPD cases (100%). Comparison between automated vs expert-bases manual classification of normal (r2 = 0.96) and tumor cell populations (rho = 0.99) showed a high degree of correlation. In summary, our results show that automated gating of cell populations based on the EuroFlow LST-PB data base provides an innovative, reliable and reproducible tool for fast and simplified identification of normal vs pathological B and T/NK lymphocytes in PB of CLPD patients.

Risk factors for prevalent hepatitis C virus-infection among inmates in a state prison system in Mexico.

OBJECTIVES: To estimate the prevalence of HCV-infection and identify associated factors among inmates in the State Prison System of Guanajuato in Mexico (Sep-2011 to Feb-2012). METHODS: Cross-sectional, observational study in 10 prisons in the State of Guanajuato in Mexico (2011-2012). We offered HCV-testing and applied audio computer-assisted self-interviews to all adults imprisoned in the State Prison System. We used a complex survey analysis to estimate the distribution of variables and its corresponding 95% confidence intervals, taking into consideration the expected cluster effect by common characteristics within prisons. Inverse probability weights were applied to correct potential biased estimates arising from non-participation in accrual activities and non-response rates. We fitted multivariate logistic regression models to identify risk-behaviors associated to HCV-infection. RESULTS: We included data of 2,519 participating inmates. Prevalence of HCV-infection was 4.9 (95%CI = 3.6-5.9). Most HCV-infected inmates were male (99%). Before being incarcerated, inmates with HCV-infection were more frequently tattooed, used and injected drugs more frequently, and were more likely to share materials for injecting, when compared with those non-infected. During incarceration, HCV-infected inmates got tattoos and used drugs more often than non-infected, including injecting-drugs and sharing materials. Injecting-drug use (OR = 7.6, 95%CI, 2.5-23.4), sharing materials for injecting-drugs (OR = 19.6, 95%CI, 4.7-81.7) and being tattooed at least once before incarceration (OR = 2.1, 95%CI, 1.1-3.9), but not during incarceration, were independently associated to HCV-infection. CONCLUSIONS: The prevalence of HCV-infection among inmates in the State of Guanajuato in Mexico is considerably higher than in the general population. The most important risk factors for HCV in this inmate population were injecting-drugs and sharing materials for injections before incarceration. High-risk behaviors during imprisonment are very high particularly among those already infected. HCV diagnostic and treatment services, and harm-reduction programs for incarcerated injecting-drug users in Mexico should be integrated to control the HCV epidemic in Mexico.

Burden of HIV, Syphilis, and Hepatitis B and C Among Inmates in a Prison State System in Mexico.

We studied the prevalence of HIV, syphilis, hepatitis B virus (HBV), and hepatitis C virus (HCV) infection and associated risk behaviors in the prison state system of Guanajuato, Mexico between September 2011 and February 2012. Blood samples were drawn from adult inmates in all State prisons who agreed to participate in this cross-sectional study. Data on risk behaviors were collected by using self-administered questionnaires. The prevalence of HIV, syphilis, HBV, and HCV infection was 0.6% [95% confidence interval (CI) = 0.2-1.1], 0.7% (95% CI = 0.4-1.0), 0.4 (95% CI = 0.04-0.74), and 4.8 (95% CI = 3.6-5.9), respectively. Female inmates had a higher prevalence of HIV (1.5% vs. 0.6%, p = .05), whereas male inmates had a higher prevalence of HCV (1% vs. 5%, p = .008). Twenty percent (n = 443, 95% CI = 15-26) of the participants were tattooed during incarceration, and most of them were tattooed with recycled materials. Around 60% (57%, 95% CI = 49-65) used drugs before incarceration, and 9.2% (n = 205) used injected drugs. During incarceration, 30% (95% CI = 23-39) used drugs and 43 continued injecting (20% of users). Consistent condom use was low among men before incarcerations but decreased by half during incarceration. The highest consistent condom use before incarceration was among men who have sex with men (MSM) (17.7%, 95% CI = 14-22), but it decreased (9%, 95% CI = 3-14) during incarceration. The prevalence of HIV, HBV, HCV, and syphilis in these inmates is higher than that of the local adult population. Most inmates had sex in prison, but few used condoms consistently. Access to condoms is apparently harder for MSM. Interventions to increase condom use, reduce use of shared or recycled materials for tattooing and injecting drugs, and treatment for drug abuse are needed.