Quantitative analysis of collagen deposition in the TZ in HIV-1–infected persons. Tissues were stained with a modified trichrome stain using the Masson method to identify collagen fibers as blue. (a) HIV-negative patient. Collagen makes up 0.23% of the tissue section. (b) Patient 1407. Section shows collagen deposition (stained blue) in the wall of the high endothelial venule. Percent area collagen was calculated to be 2.2%. (c) Patient 1327, the patient with AIDS. In contrast to b, this section shows significant deposition of collagen in the TZ. Percent area collagen was calculated to be 18.6%. A total of 18 images from each tissue sample, imported through the Photoshop program (Adobe, Version 6.0), are displayed (magnification, ×40). (d) The transformed Photoshop image from c. All shades of blue representing collagen in c were averaged and displayed in black; non-collagen area was removed. This image was imported into the MetaMorph imaging program and the percent area in black was calculated.