Summary Understanding gut microbiota alterations associated with HIV-infection and factors that drive these alterations may help explain gut-linked diseases prevalent with HIV. 16S rRNA sequencing of feces from HIV infected individuals revealed that HIV infection is associated with highly characteristic gut community changes and antiretroviral therapy does not consistently restore the microbiota to an HIV-negative state. Despite the chronic gut inflammation characteristic of HIV infection, the associated microbiota showed limited similarity with other inflammatory states and instead showed increased, rather than decreased, diversity. Metaanalysis revealed that the microbiota of HIV-infected individuals in the US was most similar to a Prevotella-rich community composition typically observed in healthy individuals in agrarian cultures of Malawi and Venezuela and related to that of US individuals with carbohydrate-rich/ protein- and fat-poor diets. By evaluating innate and adaptive immune responses to lysates from bacteria that differ with HIV, we explore the functional drivers of these compositional differences.

Objectives-Measurement of transglutaminase autoantibodies (TGAA) is considered to be the most efficient single serologic test for celiac disease (CD) by the American Gastroenterological Association Institute. We hypothesized that a large international collaborative effort toward improving and standardizing TGAA measurement is both feasible and necessary. The primary aim of this workshop is to compare TGAA assays among various research and clinical laboratories and examine assay concordance and improve (and eventually standardize) the TGAA assay. Guarantor of the article: Edwin Liu, MD. Methods Specific author contributions:Marcella Li: performed the bulk of the labor with organizing/aliquoting the sera, shipping, and performing related assays; Liping Yu: responsible for the quality control of our radioassay and also helped with data analysis, trouble shooting, planning details of the workshop. Our laboratory was used as a "reference lab"; Claudio Tiberti: contributed sera to the workshop, helped plan initial stages of workshop and paper preparation; Margherita Bonamico: participated in data analysis and paper preparation; Iman Taki: in charge of collecting the bulk of our sera at the institution and organizing the workshop; Dongmei Miao: technician performed radioassay and also performed the assay to serve as a reference for other laboratories; Joseph A. Murray: organized the workshop and paper preparation; Marian J. Rewers: contributed sera for our laboratory and helped plan the workshop; Edward J. Hoffenberg: mentor for the senior author, provided help in planning the workshop and recruiting participants; Daniel Agardh: contributed sera for the workshop, data analysis, and paper preparation; Patricia Mueller: contributed the control sera for the workshop, data analysis, and paper preparation; Martin Stern and Ezio Bonifacio: planned the details of the workshop, data analysis, and paper preparation; Edwin Liu: organized the workshop, communication with participants, overseeing our laboratory, data analysis, and paper preparation. NIH Public Access Author ManuscriptAm J Gastroenterol. Author manuscript; available in PMC 2010 July 15. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript radiobinding assays. A total of 150 serum samples were distributed to each laboratory, with each laboratory receiving an equal aliquot that was coded and blinded, composed of 100 healthy control sera and 50 CD sera.Results-Laboratory sensitivity ranged from 69% to 93% and specificity ranged from 96% to 100%. By receiver operator characteristic analysis, the area under the curve (C index) ranged from 0.9488 to 0.9904. When analyzing for linear correlation, r-squared was as high as 0.8882 but as low as 0.4244 for the celiac samples between different laboratories performing ELISA.Conclusions-This transglutaminase autoantibody workshop allows for larger-scale international participation for the purposes of improving and eventually standardizing the TGAA assay with subsequent workshops.

No abstract

Measuring DGP antibodies may be more useful than TGAA in monitoring children on a gluten-free diet. DGP antibodies can precede the appearance of TGAA in some at-risk children.