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Characterization of Baseline Intestinal Mucosal Indices of Injury and Inflammation in Men for Use in Rectal Microbicide Trials (HIV Prevention Trials Network-056)

McGowan, Ian MD, PhD, FRCP*; Elliott, Julie MS*; Cortina, Galen MD, PhD; Tanner, Karen BA, BS*; Siboliban, Chomchay BA*; Adler, Amy RN, MSN, FNP*; Cho, Daniel MD*; Boscardin, W John PhD; Soto-Torres, Lydia MD, MPH§; Anton, Peter A MD*

JAIDS Journal of Acquired Immune Deficiency Syndromes: December 1st, 2007 - Volume 46 - Issue 4 - p 417-425
doi: 10.1097/QAI.0b013e318156ef16
Clinical Science

Objectives: The purpose of this study was to evaluate the biologic stability of mucosal parameters that might be used as endpoints in phase 1 rectal safety studies.

Methods: Sixteen male participants were enrolled into 4 groups defined by HIV status, viral load, and sexual activity. Each participant underwent 3 flexible sigmoidoscopies at 2-week intervals with collection of blood, intestinal biopsies, and rectal secretions. Intestinal histology, phenotypic characterization of mucosal mononuclear cells, cytokine messenger RNA (mRNA) profiles (RANTES, interferon-γ [IFNγ], and interleukin-10), and immunoglobulin secretion were assessed. Intraclass correlation (ICC) was calculated to assess endpoint stability.

Results: Qualitative histology demonstrated minimal inflammation in >95% of biopsies and remained stable throughout the study period. ICC for the tissue cytokine mRNA measurements and several T-cell phenotypic markers was >0.7, indicating stability over time. Mucosal CD4 lymphopenia was seen in the HIV-positive participants and was more pronounced in those with higher viral loads. Modest differences were observed for cytokine expression (IFNγ) and T-cell phenotype (CD3, CD4, CD8, CD19, CD4/CCR5, and CD4/CD38) between the tissue samples collected at 10 and 30 cm.

Conclusions: These data help to provide a rationale for the selection of endpoints for future phase 1 rectal safety studies.

From the *Center for Prevention Research in the Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA; †Department of Pathology, David Geffen School of Medicine, University of California, Los Angeles, CA; ‡Departments of Biostatistics and Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA; and the §National Institute of Allergy and Infectious Diseases, Bethesda, MD.

Received for publication January 30, 2007; accepted July 30, 2007.

Funded by a grant from the HIV Prevention Trials Network of the Division of AIDS, National Institute of Allergy and Infectious Diseases, National Institutes of Health (AI46749/645-12).

Study data presented as an oral presentation at Microbicides 2006; 2006; Cape Town, South Africa.

Correspondence to: Ian McGowan, MD, PhD, FRCP, Magee Womens Research Institute, University of Pittsburgh, 204 Croft Ave., Room B505, Pittsburgh, PA 15213 (e-mail: mcgowanim@mail.magee.edu).

© 2007 Lippincott Williams & Wilkins, Inc.