No abstract

Analysis of RNA expression using techniques like real-time PCR has traditionally used reference or housekeeping genes to control for error between samples. This practice is being questioned as it becomes increasingly clear that some housekeeping genes may vary considerably in certain biological samples. We used real-time reverse transcription PCR (RT-PCR) to assess the levels of 13 housekeeping genes expressed in peripheral blood mononuclear cell culture and whole blood from healthy individuals and those with tuberculosis. Housekeeping genes were selected from conventionally used ones and from genes reported to be invariant in human T cell culture. None of the commonly used housekeeping genes [e.g., glyceraldehyde-phosphate-dehydrogenase (GAPDH)] were found to be suitable as internal references, as they were highly variable (>30-fold maximal variability). Furthermore, genes previously found to be invariant in human T cell culture also showed large variation in RNA expression (>34-fold maximal variability). Genes that were invariant in blood were highly variable in peripheral blood mononuclear cell culture. Our data show that RNA specifying human acidic ribosomal protein was the most suitable housekeeping gene for normalizing mRNA levels in human pulmonary tuberculosis. Validations of housekeeping genes are highly specific for a particular experimental model and are a crucial component in assessing any new model.

No abstract

Objectives Across Europe, almost a third of individuals infected with HIV do not enter health care until late in the course of their infection. Surveillance to identify the extent to which late presentation occurs remains inadequate across Europe and is further complicated by the lack of a common clinical definition of late presentation. The objective of this article is to present a consensus definition of late presentation of HIV infection. Methods Over the past year, two initiatives have moved towards a harmonized definition. In spring 2009, they joined efforts to identify a common definition of what is meant by a ‘late‐presenting’ patient. Results Two definitions were agreed upon, as follows. Late presentation: persons presenting for care with a CD4 count below 350 cells/μL or presenting with an AIDS‐defining event, regardless of the CD4 cell count. Presentation with advanced HIV disease: persons presenting for care with a CD4 count below 200 cells/μL or presenting with an AIDS‐defining event, regardless of the CD4 cell count. Conclusion The European Late Presenter Consensus working group believe it would be beneficial if all national health agencies, institutions, and researchers were able to implement this definition (either on its own or alongside their own preferred definition) when reporting surveillance or research data relating to late presentation of HIV infection.

Objective:The objective of this study is to estimate life expectancies of HIV-positive patients conditional on response to antiretroviral therapy (ART).Methods:Patients aged more than 20 years who started ART during 2000–2010 (excluding IDU) in HIV clinics contributing to the UK CHIC Study were followed for mortality until 2012. We determined the latest CD4+ cell count and viral load before ART and in each of years 1–5 of ART. For each duration of ART, life tables based on estimated mortality rates by sex, age, latest CD4+ cell count and viral suppression (HIV-1 RNA <400 copies/ml), were used to estimate expected age at death for ages 20–85 years.Results:Of 21 388 patients who started ART, 961 (4.5%) died during 110 697 person-years. At start of ART, expected age at death [95% confidence interval (CI)] of 35-year-old men with CD4+ cell count less than 200, 200–349, at least 350 cells/μl was 71 (68–73), 78 (74–82) and 77 (72–81) years, respectively, compared with 78 years for men in the general UK population. Thirty-five-year-old men who increased their CD4+ cell count in the first year of ART from less than 200 to 200–349 or at least 350 cells/μl and achieved viral suppression gained 7 and 10 years, respectively. After 5 years on ART, expected age at death of 35-year-old men varied from 54 (48–61) (CD4+ cell count <200 cells/μl and no viral suppression) to 80 (76–83) years (CD4+ cell count ≥350 cells/μl and viral suppression).Conclusion:Successfully treated HIV-positive individuals have a normal life expectancy. Patients who started ART with a low CD4+ cell count significantly improve their life expectancy if they have a good CD4+ cell count response and undetectable viral load.