Screening anal dysplasia in HIV-infected patients: is there an agreement between anal pap smear and high-resolution anoscopy-guided biopsy?
OBJECTIVE
The purpose of this study was to analyze the agreement between anal Pap smear and high-resolution anoscopy-guided biopsy in diagnosing anal dysplasia in HIV-infected patients.


METHODS
We conducted cross-sectional analysis of HIV-infected patients receiving anal dysplasia screening as part of routine care. Agreement between measures was estimated by weighted kappa statistics, using a three-tiered cytologic and histologic grading system (normal, low-grade dysplasia, and high-grade dysplasia). Estimates of sensitivity, specificity, and predictive values were calculated using a two-tiered cytologic and histologic grading system ("without dysplasia" and "with dysplasia of any grade"). Estimates were also calculated for the detection of high-grade dysplasia.


RESULTS
During a one-year period, 222 patients underwent 330 anal Pap smears followed by high-resolution anoscopy-guided biopsies. There were 311 satisfactory Pap smears with concurrent biopsies. Considering histology the standard, the frequency of anal dysplasia was 46%. Kappa agreement between anal Pap smear and biopsy was 0.20. For detection of anal dysplasia of any grade, anal Pap smear showed sensitivity of 61%, specificity of 60%, positive predictive value of 56%, and negative predictive value of 64%. For high-grade dysplasia, anal Pap smear showed sensitivity of 16% and specificity of 97%.


CONCLUSIONS
Anal Pap smears alone were not sensitive enough to rule out anal dysplasia. We recommend that high-resolution anoscopy-guided biopsy be incorporated as a complementary screening test for anal dysplasia in high-risk patients. Following baseline high-resolution anoscopy, these individuals could be followed with serial anal cytology to dictate the need for future high-resolution anoscopy-guided biopsies.
Nahas
Caio S R
CS
Department of Gastroenterology, Surgical Division, University of São Paulo, School of Medicine, São Paulo, SP, 01308-050, Brazil. caionahas@uol.com.br
da Silva Filho
Edesio V
EV
Segurado
Aluisio A C
AA
Genevcius
Raphael F F
RF
Gerhard
Renê
R
Gutierrez
Eliana B
EB
Marques
Carlos F S
CF
Cecconello
Ivan
I
Nahas
Sergio C
SC
D000328:Adult; D000368:Aged; D001003:Anal Canal / Q000473:pathology* / Q000821:virology; D001004:Anus Diseases / Q000175:diagnosis* / Q000821:virology; D001706:Biopsy; D003430:Cross-Sectional Studies; D003581:Cytodiagnosis / Q000379:methods*; D016099:Endoscopy, Gastrointestinal; D005260:Female; D006679:HIV Seropositivity / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity