Detection of high nerve growth factor serum levels in AIDS-related and -unrelated Kaposi's sarcoma patients.
OBJECTIVE
Nerve growth factor (NGF) is an autocrine survival factor for memory B lymphocytes. As functional B-cell deregulation is present during HIV infection, NGF serum levels were measured in HIV-infected patients and compared with the patients' clinical features.


METHODS
Sera from 48 consecutive HIV-infected patients and matched healthy controls were retrospectively and blindly analysed. Sera from seven patients with classical Kaposi's sarcoma (KS) were subsequently included in the study. The effects of NGF on spindle-shaped cells from KS lesions (KS cells) were also investigated.


METHODS
NGF titration was performed by enzyme-linked immunosorbent assay (ELISA) and human herpesvirus 8 (HHV-8) antibody testing by immunofluorescent assay (IFA). NGF receptors were assessed by Western blot analysis. Cell growth assays were performed by cell counting.


RESULTS
Very high median NGF serum levels were detected in all seven patients with AIDS-related KS (2500 pg/ml) compared with HIV-infected patients without KS (40 pg/ml), as well as in all seven classical KS patients (550 pg/ml) compared with healthy controls (20 pg/ml). In HIV-infected patients, NGF serum levels were significantly related to KS (P=0.0038) by stepwise multiple regression analysis, and HHV-8 seropositivity was significantly associated with KS (P=0.045) and to NGF levels (P=0.001) by logistic regression analysis. KS cells did not produce NGF but expressed both NGF receptors and presented increased proliferation rate after exogenous NGF addition.


CONCLUSIONS
These results strongly suggest that increased NGF levels, possibly related to HHV-8 infection, may be involved in KS progression.
Pica
F
F
Department of Experimental Medicine and Biochemical Sciences, University Tor Vergata, Rome, Italy.
Volpi
A
A
Barillari
G
G
Fraschetti
M
M
Franzese
O
O
Vullo
V
V
Garaci
E
E
D000914:Antibodies, Viral / Q000097:blood; D015658:HIV Infections / Q000097:blood* / Q000150:complications; D006566:Herpesviridae Infections / Q000150:complications; D019288:Herpesvirus 8, Human / Q000276:immunology; D006801:Humans; D007124:Immunoenzyme Techniques; D009414:Nerve Growth Factors / Q000097:blood*; D012189:Retrospective Studies; D012514:Sarcoma, Kaposi / Q000097:blood* / Q000150:complications / Q000821:virology; D014407:Tumor Cells, Cultured
D000914:Antibodies, Viral; D009414:Nerve Growth Factors