Genetic diversity of currently circulating rubella viruses: a need to define more precise viral groups.

Recent studies have shown that the currently circulating rubella viruses are mostly members of two genotypes, 1E and 2B. Also, genetically distinct viruses of genotype 1G have been found in East and West Africa. This study used a Mantel test to objectively include both genetic diversity and geographic location in the definition of lineages, and identified statistically justified lineages (n=13) and sub-lineages (n=9) of viruses within genotypes 1G, 1E and 2B. Genotype 2B viruses were widely distributed, while viruses of genotype 1E as well as 1G and 1J were much more geographically restricted. This analysis showed that more precise groupings for rubella viruses are possible, which should improve the ability to track rubella viruses worldwide. A year-by-year analysis revealed gaps in surveillance that need to be resolved in order to support the surveillance needed for enhanced control and elimination goals for rubella.

Development of an improved RT-LAMP assay for detection of currently circulating rubella viruses.

Rubella virus is the causative agent of rubella. The symptoms are usually mild, and characterized by a maculopapular rash and fever. However, rubella infection in pregnant women sometimes can result in the birth of infants with congenital rubella syndrome (CRS). Global efforts have been made to reduce and eliminate CRS. Although a reverse transcription-loop-mediated isothermal amplification (RT-LAMP) assay for detection of rubella virus has been reported, the primers contained several mismatched nucleotides with the genomes of currently circulating rubella virus strains. In the present study, a new RT-LAMP assay was established. The detection limit of this assay was 100-1000PFU/reaction of viruses for all rubella genotypes, except for genotype 2C, which is not commonly found in the current era. Therefore, the new RT-LAMP assay can successfully detect all current rubella virus genotypes, and does not require sophisticated devices like TaqMan real-time PCR systems. This assay should be a useful assay for laboratory diagnosis of rubella and CRS.

Identification of serologic markers for school-aged children with congenital rubella syndrone

BACKGROUND: Congenital rubella syndrome (CRS) case identification is challenging in older children since laboratory markers of congenital rubella virus (RUBV) infection do not persist beyond age 12 months. METHODS: We enrolled children with CRS born between 1998 and 2003 and compared their immune responses to RUBV with those of their mothers and a group of similarly aged children without CRS. Demographic data and sera were collected. Sera were tested for anti-RUBV immunoglobulin G (IgG), IgG avidity, and IgG response to the 3 viral structural proteins (E1, E2, and C), reflected by immunoblot fluorescent signals. RESULTS: We enrolled 32 children with CRS, 31 mothers, and 62 children without CRS. The immunoblot signal strength to C and the ratio of the C signal to the RUBV-specific IgG concentration were higher (P < .029 for both) and the ratio of the E1 signal to the RUBV-specific IgG concentration lower (P = .001) in children with CRS, compared with their mothers. Compared with children without CRS, children with CRS had more RUBV-specific IgG (P < .001), a stronger C signal (P < .001), and a stronger E2 signal (P ≤ .001). Two classification rules for children with versus children without CRS gave 100% specificity with >65% sensitivity. CONCLUSIONS: This study was the first to establish classification rules for identifying CRS in school-aged children, using laboratory biomarkers. These biomarkers should allow improved burden of disease estimates and monitoring of CRS control programs. Published by Oxford University Press on behalf of the Infectious Diseases Society of America 2014. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Rubella and measles seroprevalence among women of childbearing age, Argentina, 2002.

To assess rubella and measles susceptibility among women of childbearing age we conducted a cross-sectional seroprevalence study in four cities and one rural area in Argentina. A convenience sample of women aged 15-49 years seeking care in public health-care institutions was selected (n=2804). Serum specimens were tested for rubella and measles IgG antibody titres. The overall susceptibility to rubella and measles was 8.8 and 12.5% respectively. Seroprevalence differences were found for both rubella (P<0.001) and measles (P=0.002) across sites. Rubella seroprevalence was higher in women aged >or=40 years than in younger women (P=0.04). Measles seroprevalence tended to increase with age (P<0.001). Approximately 15% of women aged 15-29 years were not immune to measles. No risk factors were associated with rubella seronegativity; however, age (P<0.001) and having less than four pregnancies (P<0.001) were factors associated with measles seronegativity. Our findings support the introduction of supplemental immunization activities targeting adolescents and young adults to prevent congenital rubella syndrome and measles outbreaks over time.

Comparative detection of measles and rubella IgM and IgG derived from filter paper blood and serum samples.

We compared the use of serum and filter paper blood spots as specimen sources for the detection of measles- and rubella-specific IgM and IgG. We collected capillary blood into microtainer tubes and onto filter paper spots from 60 children and 60 healthy adults. The blood was collected from 12-15-month-old children approximately 3 weeks after primary vaccination with measles, mumps, rubella vaccine, and the sample-pairs were tested for measles-specific IgM and IgG antibodies by using a capture antibody EIA and an indirect EIA, respectively. We tested sample-pairs from a subset of participants for rubella- specific IgM and IgG antibodies by using commercially available capture IgM (Captia) and indirect IgG (Wampole) assays. The concordance of results from serum and filter paper blood spots was high for all assays: 98% for measles IgM, 93% for measles IgG, 94% for rubella IgM, and 93% for rubella IgG, and increased to between 96-100% for all four assays when indeterminate samples were excluded. The correlation coefficients for EIA signals were 0.99 and 0.77 for measles IgM and IgG, respectively, and 0.92 and 0.94 for rubella IgM and IgG, respectively. The cut-off values used for filter paper samples were the same as those used for serum samples for all tests except for the rubella IgM assay. The use of filter paper blood spots is a promising future option for the detection of measles- and rubella-specific antibodies.

A large rubella outbreak with spread from the workplace to the community.

CONTEXT: Childhood vaccination has reduced rubella disease to low levels in the United States, but outbreaks continue to occur. The largest outbreak in the past 5 years occurred in Nebraska in 1999. OBJECTIVES: To examine risk factors for disease, susceptibility of the risk population, role of vaccine failure, and the need for new vaccination strategies in response to the Nebraska rubella outbreak. DESIGN, SETTING, AND PATIENTS: Investigation of 83 confirmed rubella cases occurring in Douglas County, Nebraska, between March 23 and August 24, 1999; serosurvey of 413 pregnant women in the outbreak locale between October 1998 and March 1999 (prior to outbreak) and April and November 1999 (during and after outbreak). MAIN OUTCOME MEASURES: Case characteristics, compared with that of the general county population; area childhood rubella vaccination rates; and susceptibility among pregnant women before vs during and after the outbreak. RESULTS: All 83 rubella cases were unvaccinated or had unknown vaccination status and fell into 3 groups: (1) 52 (63%) were young adults (median age, 26 years), 83% of whom were born in Latin American countries where rubella vaccination was not routine. They were either employed in meatpacking plants or were their household contacts. Attack rates in the plants were high (14.4 per 1000 vs 0. 19 per 1000 for general county population); (2) 16 (19%), including 14 children (9 of whom were aged <12 months) and 2 parents, were US-born and non-Hispanic, who acquired the disease through contacts at 2 day care facilities (attack rate, 88.1 per 1000); and (3) 15 (18%) were young adults (median age, 22 years) whose major disease risk was residence in population-dense census tracts where meatpacking-related cases resided (R(2) = 0.343; P<.001); 87% of these persons were born in Latin America. Among pregnant women, susceptibility rates were 13% before the outbreak and 11% during and after the outbreak. Six (25%) of 24 susceptible women tested were seropositive for rubella IgM. Rubella vaccination rates were 90.2% for preschool children and 99.8% for school-aged children. CONCLUSIONS: A large rubella outbreak occurred among unvaccinated persons in a community with high immunity levels. Crowded working and living conditions facilitated transmission, but vaccine failure did not. Workplace vaccination could be considered to prevent similar outbreaks. JAMA. 2000;284:2733-2739.

Papillomavirus detection: demographic and behavioral characteristics influencing the identification of cervical disease.

OBJECTIVE: This study was undertaken to assess the association between detection of high-risk types of human papillomavirus and various demographic and behavioral characteristics and to further relate this association to cervical histopathologic findings. STUDY DESIGN: A total of 1007 patients with a Papanicolaou test result reported as high-grade squamous intraepithelial lesion or with 2 results reported as atypical squamous cells of undetermined significance or low-grade squamous intraepithelial lesion were referred from city and county clinics to a colposcopic clinic. All women had a cervical smear obtained, underwent colposcopically directed biopsy and endocervical curettage, and had a specimen taken for human papillomavirus deoxyribonucleic acid detection by polymerase chain reaction. Demographic information was obtained from each patient. RESULTS: Human papillomavirus deoxyribonucleic acid was identified in 655 (66%) of the specimens. High-risk human papillomavirus types (16, 18, 31, 33, and 35) were detected in 463 (70.7%) of these specimens. The prevalence of evidence of human papillomavirus (koilocytosis) and grade 1 cervical intraepithelial neoplasia in the biopsy specimen decreased significantly with age, whereas the prevalence of grade 2 or 3 cervical intraepithelial neoplasia in the biopsy specimen increased with age. There was a significant age-dependent decreasing trend in detection of high-risk human papillomavirus deoxyribonucleic acid among women who had human papillomavirus-associated changes, grade 1 cervical intraepithelial neoplasia, and grade 2 or 3 cervical intraepithelial neoplasia in the biopsy specimen. The prevalences of high-risk human papillomavirus among patients with grade 1 cervical intraepithelial neoplasia and grade 2 or 3 cervical intraepithelial neoplasia were similar, and both were significantly higher than among women with no evidence of cervical intraepithelial neoplasia or koilocytosis in the biopsy specimen. Risk factors associated with grade 2 or 3 cervical intraepithelial neoplasia were different from those associated with human papillomavirus-associated changes and with grade 1 cervical intraepithelial neoplasia. CONCLUSION: The detection of high-risk human papillomavirus was age-dependent for all histologic categories. Patients with grade 2 or 3 cervical intraepithelial neoplasia had a prevalence of high-risk human papillomavirus that was similar to that among women with grade 1 cervical intraepithelial neoplasia but significantly higher than that among women whose biopsy specimens appeared normal or demonstrated only the presence of human papillomavirus-induced changes (koilocytosis). This suggests that separation of human papillomavirus-associated changes only from grade 1 cervical intraepithelial neoplasia may be of significance in tissue diagnosis.

Human papillomavirus (HPV) DNA copy number is dependent on grade of cervical disease and HPV type.

The association between human papillomavirus (HPV) DNA copy number and cervical disease was investigated. Viral DNA copy number for the most common high-risk HPV types in cervical cancer (types 16, 18, 31, and 45) was determined in cervical cytobrush specimens from 149 women with high-grade cervical intraepithelial neoplasias (CIN II-CIN III), 176 with low-grade CIN (CIN I), and 270 with normal cytology. Quantitative, PCR-based fluorescent assays for each of the HPV genotypes and for the beta-globin gene were used. The amount of cellular DNA increased significantly with increasing disease; thus, HPV was expressed as copies per microgram of cellular DNA. The assay had a dynamic range of >10(7), allowing documentation for the first time of the wide range of HPV copy numbers seen in clinical specimens. Median HPV DNA copy number varied by more than 10(4) among the viral types. HPV16 was present in the highest copy number; over 55% of HPV16-positive samples contained more than 10(8) copies/microgram. Median copy number for HPV16 showed dramatic increases with increasing epithelial abnormality, an effect not seen with the other HPV types. HPV16 increased from a median of 2.2 x 10(7) in patients with normal cytology, to 4.1 x 10(7) in CIN I patients, to 1.3 x 10(9) copies/microgram in CIN II-III patients. Even when stratified by cervical disease and viral type, the range of viral DNA copies per microgram of cellular DNA was quite large, precluding setting a clinically significant cutoff value for "high" copy numbers predictive of disease. This study suggests that the clinical usefulness of HPV quantitation requires reassessment and is assay dependent.

A case-control study of human papillomavirus and cervical squamous intraepithelial lesions (SIL) in Harris County, Texas: differences among racial/ethnic groups.

We conducted a case-control study of the association between SIL and HPV among whites (W), African Americans (AA), and Hispanics (H) in Harris County, Texas. Cases were identified at M.D. Anderson Cancer Center Colposcopy Clinic. Controls were identified among women obtaining routine Pap screening at two Harris County Health Department Clinics. HPV was detected by a PCR-based fluorescent assay. Dichotomous and polytomous logistic regression models were used to estimate adjusted odd ratios (AOR) and 95% confidence intervals (CI) for SIL among racial/ethnic groups and grade of disease. Prevalence of HPV infection was 64% in low grade SIL (LSIL), 84% in high grade SIL (HSIL), and 19% in controls. Risk of SIL was higher in H than in W and AA, AOR 29.5 (12.4-70.5), 15.3 (6.0-33.8), and 5.8 (2.6-12.6), respectively. Similarly, racial/ethnic differences were observed for both LSIL (AOR = 16.6, 7.7, and 4.3, respectively) and HSIL (AOR = 78.6, 34.6, and 14.2, respectively). Findings support the association between SIL and HPV and differences in the strength of the association with LSILs and HSILs. Data also suggest a higher risk for H and a lower risk for AA.

Expression of ras, c-myc, and p53 proteins in cervical intraepithelial neoplasia.

BACKGROUND: The development of cervical carcinoma is influenced by multiple factors, including the presence of certain high risk types of human papillomavirus. The purpose of the current study was to investigate possible cooperating genetic changes by examining the expression of p53, p62 myc, and p21 ras in cervical biopsy specimens. METHODS: Three hundred and ninety-five cervical biopsy specimens representing normal through high grade cervical intraepithelial neoplasia (CIN) were screened by immunohistochemistry for expression of p53, p62myc, and p21ras. RESULTS: Neither the proportion of tissues staining positive for a given protein nor the staining patterns within the epithelial layers differed significantly among normal or CIN biopsy samples. However, grade specific nuclear staining of p21ras was found in the cells of 10 lesions that were classified as CIN I by histology. CONCLUSIONS: These results established the normal distribution and expression patterns of p53, p62myc, and p21ras within 395 cervical biopsy samples representing normal through CIN III histology. The expression of these proteins (e.g., staining intensity and layer of epithelium staining positive) is similar in normal tissues and those demonstrating all grades of CIN.

Is human papillomavirus testing an effective triage method for detection of high-grade (grade 2 or 3) cervical intraepithelial neoplasia?

OBJECTIVE: Our purpose was to assess the usefulness of the polymerase chain reaction assay for detection of human papillomavirus infection for prognostic value in the triage strategies for high-grade (grade 2 or 3) cervical intraepithelial neoplasia in women referred for colposcopy after abnormal Papanicolaou smears. STUDY DESIGN: A total of 1007 women referred to a colposcopic clinic providing care for an indigent population were studied. Four hundred fifty-four women were referred after two Papanicolaou smears reported as atypical squamous cells of undetermined significance or low grade-squamous cervical intraepithelial lesion, and 553 were referred after a single smear reported as high-grade squamous intraepithelial lesion. All women had a cervical smear, colposcopy-directed biopsy, and endocervical curettage performed. A sample for human papillomavirus deoxyribonucleic acid detection by polymerase chain reaction was obtained. RESULTS: High-risk human papillomavirus types were detected in 463 (46%) of 1007 women studied. There was a significant increase of the frequency of high-risk human papillomavirus by the increasing severity of biopsy findings ranging from 32.7% in women without cervical intraepithelial neoplasia on biopsy to 60% in women having grade 2 or 3 on the biopsy specimen. Women having a negative Papanicolaou smear found to have high-risk human papillomavirus deoxyribonucleic acid at the time of colposcopy had a significantly higher rate of grade 2 or 3 cervical intraepithelial neoplasia on the biopsy specimen than did women without high-risk human papillomavirus. There was no such difference observed in women with a cytologic finding of low- or high-grade squamous intraepithelial lesions at the time of colposcopy. The polymerase chain reaction assay appears to be more sensitive than the commercial human papillomavirus profile test. The positive predictive value for grade 2 or 3 cervical intraepithelial neoplasia of both tests was similar (21.7% and 22.8%, respectively). CONCLUSION: The human papillomavirus is associated with high-grade cervical intraepithelial neoplasia, but the screening for human papillomavirus deoxyribonucleic acid does not have prognostic value in women reported as having atypical squamous cells of undetermined significance or low-grade squamous intraepithelial lesions on two precolposcopy Papanicolaou smears.

Human papillomavirus and disease status following therapy for cervical cancer.

We enrolled 85 patients with invasive cervical cancer and collected cervicovaginal lavage samples at each clinical visit for diagnosis, staging, treatment, and follow-up. Lavage samples were tested by L1 consensus polymerase chain reaction for human papillomavirus (HPV). Results were compared with HPV demonstrated in tumor tissue and the clinical status at time of sample collection. Sensitivity and specificity of the lavage for detection of tumor HPV, determined on the basis of results of tests on lavage samples collected prior to therapy, were found to be 56% and 76.9%, respectively. The proportion of lavage samples detecting tumor HPV decreased significantly with treatment, from 0.54 at diagnosis to 0.03 at complete response (P < .001). Local treatment failure was associated with increased detection of tumor HPV; however, no samples were positive prior to clinically detected treatment failure. These results suggest that cervicovaginal lavage is not an effective sampling method for epidemiological analysis of HPV in cervical tumors.

Human papillomavirus testing as triage for atypical squamous cells of undetermined significance and low-grade squamous intraepithelial lesions: sensitivity, specificity, and cost-effectiveness.

OBJECTIVE: Our purpose was to evaluate the cost-effectiveness of the use of a Food and Drug Administration-approved human papillomavirus test in triaging patients with Papanicolaou smears showing atypical squamous cells of undetermined significance or a low-grade squamous intraepithelial lesion for colposcopy compared with an algorithm that used cytologic follow-up. STUDY DESIGN: Four hundred sixty-two women referred to our Colposcopy Clinic with a Papanicolaou smear report of atypical squamous cells of undetermined significance or a low-grade squamous intraepithelial lesion underwent repeat Papanicolaou smear, cervical colposcopy, directed cervical biopsy, and endocervical curettage. In addition, human papillomavirus testing by the Food and Drug Administration-approved HPV Profile (Digene Diagnostics, Silver Spring, Md.) test was done. A comparison of sensitivity, specificity, and cost-effectiveness of an algorithm determining the need for colposcopy on the basis of repeat cytologic testing versus an algorithm that incorporated repeat cytologic testing and human papillomavirus screening was done. The cost-effectiveness of both of these triage algorithms was also compared. RESULTS: As expected, high-risk human papillomavirus deoxyribonucleic acid was detected with greater frequency in relation to increasing severity of cervical intraepithelial neoplasia. In 268 women, the follow-up smear obtained in our clinic was reported as negative. High-risk human papillomavirus types were found in 23.5% of these women. In the human papillomavirus-negative women, 5.9% had grade 2 or 3 cervical intraepithelial neoplasia confirmed on cervical biopsy. In comparison, 20.6% of those with a positive result of the human papillomavirus test had grade 2 or 3 cervical intraepithelial neoplasia on biopsy (p < 0.001). Despite this difference, the sensitivity of a positive result of a high-risk human papillomavirus test in predicting the presence of grade 2 or 3 cervical intraepithelial neoplasia was only 52%. Among the women for whom a follow-up clinic Papanicolaou smear was reported as showing atypical squamous cells of undetermined significance or a low-grade squamous intraepithelial lesion, there was no difference in the frequency of biopsy-proved grade 2 or 3 cervical intraepithelial neoplasia between those women with a positive human papillomavirus test result and those with a negative test result. Colposcopy would have been recommended for 194 women because of a repeat clinic smear revealing atypical squamous cells of undetermined significance, a low-grade squamous intraepithelial lesion, or a high-grade squamous intraepithelial lesion, and in 21.6% of these grade 2 or 3 cervical intraepithelial neoplasia was shown on biopsy (sensitivity 63%, specificity 62%). Colposcopy would have been recommended for 180 women because high-risk human papillomavirus or a high-grade squamous intraepithelial lesion was detected at the clinic visit, and in 25% of this group grade 2 or 3 cervical intraepithelial neoplasia was shown on biopsy (sensitivity 67%, specificity 66%). Sensitivity and specificity were virtually identical for the two algorithms, but the cost of human papillomavirus testing was nearly double that of triage based on repeat cytologic testing alone ($692 vs $1246 per case). CONCLUSION: The Food and Drug Administration-approved HPV Profile test is not a cost-effective triage for patients referred with Papanicolaou smears reported as showing atypical squamous cells of undetermined significance or low-grade squamous lesions.

A sensitive, type-specific, fluorogenic probe assay for detection of human papillomavirus DNA.

A simple method for the detection of a number of human papillomavirus (HPV) genotypes associated with cervical cancer has been developed. The assay exploits the 5'-->3' exonucleolytic activity of Taq DNA polymerase to increase the signal from fluorescent dyes by releasing them from genotype-specific probes during PCR. The probes are oligonucleotides with a 5' reporter dye (6-carboxyfluorescein), a quencher dye (6-carboxy-tetramethyl-rhodamine), and a phosphate-blocked 3' end. In the intact probe, the proximity of the reporter and the quencher results in suppression of reporter fluorescence by Förster-type energy transfer (V. T. Förster. Ann. Phys. 2:55-75, 1948). If the probe is bound downstream of either primer during PCR, the 5'-->3' exonucleolytic activity of Taq polymerase degrades it, allowing the reporter to diffuse away from the quencher, which results in an increase in reporter fluorescence. The increased fluorescence is directly related to the amount of target DNA and can be detected with an automated fluorometer. Probes for the L1 region of the cervical-cancer-associated HPV types 16, 18, 31, 33, and 35 were synthesized and the assays were optimized. The most sensitive assay can detect as few as two copies of HPV DNA in human cervical specimens.

Human papillomavirus type 16 DNA in esophageal carcinomas from Alaska Natives.

The possible etiological role of human papillomavirus (HPV) in esophageal carcinogenesis was evaluated in Alaska Natives in whom the incidence of esophageal cancer is 1.3 and 3.8 times higher than in US Caucasian men and women, respectively. Fixed paraffin-embedded esophageal tissues from 32 cases of squamous-cell carcinoma (SCC) and 3 cases of adenocarcinoma (AC) diagnosed between 1957 and 1988 were analyzed by polymerase chain reaction (PCR) and in situ hybridization for HPV DNA sequences. Detection of the human beta-globin gene by PCR was used as a control for sufficiency of DNA and its potential for amplification in the tissue samples. Twenty-five of the tumor tissues were considered adequate for PCR analyses; HPV DNA was detected in 10 of 22 SCCs and was not found in 3 ACs. Seven of the 10 HPV-positive tissues contained sequences from the E6 gene of HPV type 16. Koilocytosis, an epithelial change consistent with HPV infection, was found in 80% of the esophageal squamous-cell tumors with HPV DNA and in 75% of those without HPV DNA. The detection of amplifiable cellular DNA was related to recentness of diagnosis; however, the detection of HPV DNA within amplifiable specimens was not related to recentness of diagnosis. A 413-bp sequence from the L1 open reading frame of HPV 16 from esophageal tissue of 2 patients was identical to sequences previously identified in cervical cells from other Alaska Natives. Our results provide molecular evidence of HPV infection, especially type 16, in archival esophageal cancer tissues from 45% of those patients whose specimens contain adequate DNA for PCR analysis.

Relevance of human papillomavirus screening in management of cervical intraepithelial neoplasia.

OBJECTIVE: To evaluate the utility of human papillomavirus detection in identifying women with abnormal Papanicolaou smears who can be safely followed up with cytologic study only, we conducted a study to determine the sensitivity, specificity, and negative and positive predictive values of a Food and Drug Administration-approved human papillomavirus test kit for detection of cervical intraepithelial neoplasia in colposcopically directed biopsy specimens. STUDY DESIGN: We enrolled women with abnormal Papanicolaou smears referred to a colposcopy clinic serving indigent patients. All 1128 women had a referral Papanicolaou smear, a clinic Papanicolaou smear, and a sample for human papillomavirus deoxyribonucleic acid test; 1075 underwent colposcopically directed biopsies and endocervical curettage. We used the HPV Profile kit for human papillomavirus testing. RESULTS: Of 486 women with low-grade squamous intraepithelial lesions on Papanicolaou smear, 35.4% had high-risk human papillomavirus deoxyribonucleic acid detected, and of 592 with high-grade lesions, 44.4% had high-risk human papillomavirus detected. Among 527 women with biopsy specimens showing cervical intraepithelial neoplasia and in 267 with cervical intraepithelial neoplasia grades 2 or 3, 38.7% and 56.2% had high-risk human papillomavirus deoxyribonucleic acid detected. However, the sensitivity of human papillomavirus deoxyribonucleic acid detection to identify biopsy-confirmed cervical intraepithelial neoplasia grades 2 or 3 was 55.7%, and the positive predictive value of the test was only 34.9%. CONCLUSION: Human papillomavirus appears to be causally associated with cervical cancer but human papillomavirus screening does not appear to be of value to identify women with abnormal Papanicolaou smears who can be safely followed up with cytologic study alone.

Natural variants of the human papillomavirus type 16 E6 protein differ in their abilities to alter keratinocyte differentiation and to induce p53 degradation.

Three naturally occurring variant human papillomavirus type 16 (HPV-16) E6 proteins, which contained amino acid substitutions predominantly near the N terminus, exhibited significant differences in their abilities to abrogate keratinocyte differentiation in response to serum and calcium and to induce the degradation of p53 in vitro. One variant surpassed the reference E6 protein in its ability to abrogate keratinocyte differentiation responses, whereas another showed a reduction in this activity. Interestingly, the biological activities of the HPV-16 E6 proteins and their abilities to induce p53 degradation in vitro were directly correlated. These results demonstrate that naturally occurring variants of HPV-16 differ in biological and biochemical properties which might result in differences in pathogenicity.

Sequence variation in the capsid protein genes of human papillomavirus type 16 and type 31.

The sequences of the capsid genes of a human papillomavirus type 16 (HPV 16) DNA and an HPV 31 DNA were determined. The HPV 16 DNA contained genes coding for the most variable HPV 16 capsid proteins yet identified (17 variable amino acids). Three of six coding changes in the HPV 31 DNA occurred at positions equivalent to ones where variable amino acids in HPV 16 have been observed. Variable amino acids in both viruses occurred predominantly in regions which showed amino acid variation when closely related types of HPV were compared; thus, most of the factors which determined the intratypic variation in the capsid proteins of the viruses described here were likely the same as those which determined differences between the capsid proteins of different HPV types.

Divergent human papillomavirus type 16 variants are serologically cross-reactive.

It is not known whether DNA sequence variants of human papillomavirus type 16 (HPV-16) are distinct serotypes. To examine this question, the reactivities of women's sera from Zaire (n = 97) and Denmark (n = 123) were compared in IgG-specific ELISAs based on virus-like particles (VLPs) composed of the L1 major capsid protein derived from an HPV-16 variant common in central Africa (Z-1194) or one common in northern Europe (114K). These L1s differ in seven amino acids. There was a strong correlation between reactivity in the two assays for both sets of sera (correlation coefficients, 0.73 and 0.85 for Zairian and Danish sera, respectively). In only 1 serum was there evidence for a specific reaction to one but not the other VLP variant. The results support the conclusion that the virions of strains Z-1194 and 114K are serologically cross-reactive.

Cervical cancer survival in a high risk urban population.

BACKGROUND: Cervical cancer remains an important public health problem, particularly for the urban minority population. To the authors' knowledge, determinants of cervical cancer survival have not been studied in this high risk population. METHODS: This study included all 158 women diagnosed and treated for invasive cervical cancer from January 1, 1986, through December 31, 1992, at the Grady Memorial Hospital and Clinics (Atlanta, GA). Medical records were abstracted to determine age at diagnosis, race, International Federation of Gynecology and Obstetrics (FIGO) clinical stage, treatment, and survival. Pathologic material was reviewed to confirm the diagnosis. RESULTS: Most patients (80%) were African American, and the stage distribution was similar for African American and white patients. Sixty-six (42%) had FIGO Stage I disease; 50%, Stage II or III; and 8%, Stage IV. Four-year actuarial survival differed significantly according to clinical stage (Ia = 94%, Ib = 79%, II = 39%, III = 26%, IV = 0%). Overall survival was lower for patients with glandular carcinomas than for those with squamous cell carcinomas (26% vs. 55%, P = 0.09). This difference was almost entirely due to increased mortality in patients with Stage Ib adenocarcinomas (53% vs. 88% for squamous cell carcinoma, Stage Ib, P = 0.03). CONCLUSIONS: The major prognostic markers for cervical cancer survival in this high risk patient population were clinical stage and histology, factors identical to those identified for other populations.