Beta amyloid precursor protein and patterns of HIV p24 immunohistochemistry in different brain areas of AIDS patients.
OBJECTIVE
To evaluate the correlation between immunohistochemical positive patterns (globular and filamentous structures) of beta-amyloid precursor protein (beta-APP), used as a marker of axonal damage, and the different distribution of HIV p24 antigens, in three different brain areas of AIDS patients.


METHODS
Eighteen AIDS patients with HIV-related brain lesions were included in the study. Forty-nine sections from basal ganglia, frontal cortex and hippocampus were selected. After microwave oven pre-treatment, the sections were incubated with anti-HIV p24 and anti-beta-APP monoclonal antibodies; the reactions were developed with peroxidase/3,3'diaminobenzidine. The positivity was graded by semi-quantitative scores. Double immunohistochemical staining was used to evaluate the co-localization of the antigens.


RESULTS
HIV p24 immunohistochemistry was positive in 44 of 49 sections (89%), with a prevalence of interstitial positive cells and positive microglial nodules in 27 and 13 sections respectively. beta-APP-positive structures were demonstrated in 23 of 44 sections (52%) with HIV-related lesions, and were absent from the five sections without viral expression. Globular and filamentous lesions were observed in 21 of 23 sections and 10 of 23 lesions respectively. Moreover, a high grade of globular type lesion was related to an elevated presence of diffuse interstitial HIV p24-positive cells in basal ganglia; double immunohistochemical reactions demonstrated the co-localization of beta-APP globules and HIV p24 antigens.


CONCLUSIONS
The data obtained confirm the coexpression of beta-APP and viral antigens in particular areas of the brain with HIV-related lesions; there is a strict correlation between beta-APP globules (indicating chronic cerebral damage) and the interstitial pattern of HIV p24 immunohistochemistry.
Nebuloni
M
M
Pathology Unit, 'Ospedale Civile', Vimercate, the Pathologhy Unit, 'L. Sacco' Institute of Medical Science, University of Milan, Italy.
Pellegrinelli
A
A
Ferri
A
A
Bonetto
S
S
Boldorini
R
R
Vago
L
L
Grassi
M P
MP
Costanzi
G
G
D000163:Acquired Immunodeficiency Syndrome / Q000453:epidemiology / Q000378:metabolism* / Q000473:pathology / Q000821:virology; D016564:Amyloid beta-Protein Precursor / Q000378:metabolism*; D001479:Basal Ganglia / Q000378:metabolism* / Q000473:pathology / Q000821:virology; D015415:Biomarkers; D005625:Frontal Lobe / Q000378:metabolism* / Q000473:pathology / Q000821:virology; D016655:HIV Core Protein p24 / Q000378:metabolism*; D015497:HIV-1; D006624:Hippocampus / Q000378:metabolism* / Q000473:pathology / Q000821:virology; D006801:Humans; D007558:Italy / Q000453:epidemiology; D012189:Retrospective Studies
D016564:Amyloid beta-Protein Precursor; D015415:Biomarkers; D016655:HIV Core Protein p24