Serum matrix metalloproteinase levels correlate with brain injury in human immunodeficiency virus infection

Abstract

Circulating levels of specific matrix metalloproteinases (MMPs; 1 and 7) were evaluated as correlates of brain injury in eight individuals in advanced human immunodeficiency virus (HIV) infection. Neurological status was quantified in vivo with automated segmentation algorithms and with diffusion tensor imaging. Both metalloproteinases correlated with microstructural brain alterations and the degree of atrophy. MMPs may influence neurological outcome through involvement in neuroimmune response, blood-brain barrier permeability, leukocyte migration, and MMP-mediated neurotoxicity.

Figure 1

Parenchyma (white) is segmented from CSF (blue) to generate the brain parenchyma volume measure, as shown in a single axial slice. A partial 3D image of the brain is shown to illustrate that the voume is determined across the entire brain.

Figure 2

Proton density and T2 images in original gray scale (left) with segmentation of each tissue class (right) shown in red. Volume fractions are calculated across all slice levels.

Figure 3

A representative FA map shown at the level of the interventricular foramen (left). FA is calculated for each voxel containing brain tissue. Thresholding and manual editing are used to remove voxels containing primarily CSF and skull. For each subject, a histogram of the resulting FA values is generated (right) and summarized as the histogram mean. The same approach was used to generate whole brain MD values.