Clinical Aspects of the AIDS Dementia Complex in Relation to Histopathological and Immunohistochemical Variables

Abstract

To correlate cerebral histopathological and immunohistochemical changes in the neuroclinical features of the AIDS dementia complex (ADC), autopsy results of 28 ADC patients were related, in a retrospective analysis, to scores on a standardised neurological examination performed at neurologic onset. From a histopathological point of view, the cases were classified as follows: 9 cases of HIV leucoencephalopathy (HIVL; diffuse myelin damage and rare microglial nodules), 7 cases of HIV encephalitis (HIVE; several microglial nodules and no myelin damage) and 12 cases of mixed HIVL and HIVE (HIVL-E). The groups differed significantly with respect to symptoms and CD4 count at neurologic onset, survival and neurological impairment. Immunohistochemically, the interstitial component (p24-positive cells scattered singly within the white matter) was significantly more prevalent in HIVL, and the micronodular component (p24-positive cells confined within microglial nodules) in HIVE. Neurological damage was worse in cases with a high prevalence of interstitial component or a low prevalence of micronodular component. HIVE, HIVL and HIVL-E are distinct clinical forms of ADC. Neurological impairment is related to white matter damage.

P24 immunohistochemistry on lymphoid tissue: the histopathologist’s role in HIV diagnosis

“…Several publications by histopathologists in the last 25 years have explored p24 expression by immunohistochemistry in paraffin sections of tissue specimens procured at surgery for diagnosis, encompassing lymph nodes, 15,17–25 tonsil/Waldeyer’s ring, 8,9,26–29 thymus, 30 salivary gland, 31–35 brain/spinal cord, 36–42 retina, 43,44 skeletal muscle, 45 stomach, 46 bowel, 47–49 liver, 50 placenta 51–53 and others 54 . However, to the best of our knowledge only two of these studies have explored the use of p24 immunohistochemistry to diagnose HIV infection.…”

“…Isolated positive cells may also be demonstrated in bone marrow trephine biopsy specimens (unpublished observations). p 2 4 immunohistochemistry in the clinical setting Several publications by histopathologists in the last 25 years have explored p24 expression by immunohistochemistry in paraffin sections of tissue specimens procured at surgery for diagnosis, encompassing lymph nodes, 15,[17][18][19][20][21][22][23][24][25] tonsil ⁄ Waldeyer's ring, 8,9,[26][27][28][29] thymus, 30 salivary gland, [31][32][33][34][35] brain ⁄ spinal cord, [36][37][38][39][40][41][42] retina, 43,44 skeletal muscle, 45 stomach, 46 bowel, [47][48][49] liver, 50 placenta 51-53 and others. 54 However, to the best of our knowledge only two of these studies have explored the use of p24 immunohistochemistry to diagnose HIV infection.…”