title: HIV disease progression: is the Brazilian variant subtype B' (GWGR motif) less pathogenic than US/European subtype B (GPGR)?
abstract: BACKGROUND
  The aim of this study was to investigate differences in HIV disease progression in patients infected with HIV subtype B with a GPGR motif in the V3 loop region (B-GPGR) versus the Brazilian subtype B variant with a GWGR motif (B'-GWGR).
  
  
  METHODS
  Patients were enrolled in an ongoing cohort study at the University of São Paulo Dermatology Clinic in Sao Paulo, Brazil. V3 serology was performed by enzyme immunoassay with peptides representing two HIV subtype B strains, MN and SF2, and two Brazilian variant B'-GWGR strains. The incidence of AIDS-defining events was calculated, and Cox proportional hazards regression was used to estimate adjusted risk ratios.
  
  
  RESULTS
  Of the samples from 114 patients studied, 23 (20%) were classified as B'-GWGR motif, and 91 (80%) as B-GPGR motif. Patients with T CD4+ cell counts less than 200 cells/mm3 or 200-400 cells/mm3 experienced an increased incidence of AIDS-defining events compared with patients who entered the cohort with T CD4+ cell counts greater than 400 cells/mm3. In a proportional hazard model including age, gender, T CD4+ cell count at entry into the cohort, and V3 serology, GWGR reactivity was associated with a decreased hazard rate for presenting an AIDS-defining condition during follow-up. Three patients in the group with GPGR serology died after experiencing an AIDS-defining event. None of the patients with GWGR serology died during follow-up.
  
  
  CONCLUSIONS
  Survival analysis showed that patients infected with the Brazilian subtype B variant with a GWGR motif in the V3 loop had lower risk, adjusted for initial CD4+ cell count, of AIDS-defining events than patients infected with subtype B-GPGR strains.
authors.affiliation: Laboratório de Alergia e Imunologia Clínica e Experimental, Faculdade de Medicina da Universidade de São Paulo, Brazil. J31@hotmail.com
authors.forename: Jorge
authors.initials: J
authors.lastname: Casseb
authors.forename: Shirley
authors.initials: S
authors.lastname: Komninakis
authors.forename: Leslie
authors.initials: L
authors.lastname: Abdalla
authors.forename: Luis Fernando M
authors.initials: LF
authors.lastname: Brigido
authors.forename: Rosangela
authors.initials: R
authors.lastname: Rodrigues
authors.forename: Fabio
authors.initials: F
authors.lastname: Araújo
authors.forename: Ana Paula Rocha
authors.initials: AP
authors.lastname: Veiga
authors.forename: Alexandre
authors.initials: A
authors.lastname: de Almeida
authors.forename: Brendan
authors.initials: B
authors.lastname: Flannery
authors.forename: R Michael
authors.initials: RM
authors.lastname: Hendry
authors.forename: Alberto José da Silva
authors.initials: AJ
authors.lastname: Duarte
mesh_terms: D000328:Adult; D020816:Amino Acid Motifs; D019943:Amino Acid Substitution; D001938:Brazil; D015331:Cohort Studies; D018450:Disease Progression; D005260:Female; D015483:HIV Antibodies / Q000097:blood; D015699:HIV Envelope Protein gp120 / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D015658:HIV Infections / Q000503:physiopathology / Q000821:virology*; D015497:HIV-1 / Q000145:classification* / Q000235:genetics / Q000472:pathogenicity*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics* / Q000276:immunology
chemical_list: D015483:HIV Antibodies; D015699:HIV Envelope Protein gp120; C059762:HIV envelope protein gp120 (305-321); D010446:Peptide Fragments