Expression of Epstein-Barr virus encoded latent genes in nasal T cell lymphomas

AIMS

To determine the expression of Epstein-Barr (EB) virus encoded latent genes in nasal T-cell lymphomas in The Netherlands.

METHODS

Seven europid (Dutch) cases of nasal T cell lymphoma were investigated for the presence of EB virus by RNA in situ hybridisation (EBER). The expression of the EB virus encoded genes BARF0, EBNA1, EBNA2, LMP1, LMP2A, LMP2B, and ZEBRA was studied at the mRNA level using reverse transcriptase polymerase chain reaction. At the protein level the expression was investigated of EBNA2 and LMP1 by immunohistochemistry.

RESULTS

In all seven nasal T cell lymphomas EBER was detected in the nuclei of virtually all tumour cells. BARF0 mRNA was detected in all samples. EBNA1 mRNA was found in six cases, LMP1 mRNA in five, LMP2A mRNA in three, LMP2B mRNA in one, and ZEBRA mRNA in one. EBNA2 mRNA was not found in any case. At the protein level occasional LMP1 positive tumour cells were seen in only one case. The EBNA2 protein was not detected.

CONCLUSIONS

Nasal T cell lymphomas in The Netherlands are strongly associated with EB virus. The virus shows a type II latency pattern (EBNA1+, LMP1+, EBNA2-) that seems to be similar to the EB virus associated nasal T cell lymphomas in oriental countries.

HPV-16-positive anal and penile carcinomas in a young man--anogenital 'field effect' in the immunosuppressed male?

This report presents the unusual occurrence of metachronous perianal and penile carcinomas in a young, immunosuppressed man. Both anogenital cancers were HPV-16-DNA-positive by the polymerase chain reaction. DNA in situ hybridization analysis of the penile carcinoma revealed HPV-16 in most neoplastic cells. HPV-16 appears to have played a central role in both anogenital cancers in this patient, suggesting that, like in immunologically susceptible women, a carcinogenic 'field effect' may exist in the anogenital area of the immunosuppressed male.

Age-dependence of human papillomavirus DNA presence in oral squamous cell carcinomas

The aetiology of oral cancer is thought to be multifactorial. Apart from the two known major risk factors (tobacco and alcohol), a viral aetiology has been proposed, with special reference to human papillomavirus (HPV). 35 cases of oral squamous cell carcinoma (OSCC), seen at the Departments of Oral & Maxillofacial Surgery and Oral Pathology and Otolaryngology of the Free University of Amsterdam, were analysed as well as 12 biopsies of clinically and histologically normal gingival mucosa collected from healthy individuals after tooth extractions, using the polymerase chain reaction (PCR) and two different sets of primers that are able to detect a broad spectrum of HPV types. An overall HPV positivity of 54.3% in OSCC was found, the majority of positive cases (78.9%) harbouring HPV type 16. In contrast, no positivity for HPV was detected in the clinically normal oral mucosal samples analysed. Furthermore, a significant association between HPV presence and age was found: patients older than 60 years showed a lower prevalence of the virus (29.4%) compared with patients below this age (77.8%) (P < 0.05). The results from the present study suggest an association between HPV and OSCC, particularly in patients under the seventh decade.

Extracellular matrix and beta 1 integrin expression in nodal and extranodal T-cell lymphomas

Since non-Hodgkin's lymphoma (NHL) cells interact with surrounding structures similarly to their normal counterparts, micro-environmental changes and the aberrant expression of adhesion molecules are considered to be of importance in lymphomagenesis. In this immunohistochemical study, the composition of several extracellular matrix (ECM) components and the expression of their beta 1 integrin receptors were examined in nodal and extranodal T-cell NHLs. Except for the T-lymphoblastic NHLs, almost all T-NHLs displayed abundant deposition of matrix and considerable expression of the alpha 4 and beta 1 integrin chains. This is in contrast to B-cell NHLs, which show ECM patterns comparable to those in reactive lymphoid tissue or, in cases of high-grade malignancy, active matrix degradation and very low expression or absence of beta 1 integrins, as previously described. This difference is probably based on distinct cytokine production in B- and T-cell malignancies. As in B-NHL, nodal and extranodal T-NHLs of the same morphological subtype exhibit identical ECM patterns, which suggests that malignant lymphoid cells of both B and T origin create at least part of their own specific micro-environment.

Prevalence and serovar distribution of asymptomatic cervical Chlamydia trachomatis infections as determined by highly sensitive PCR

The prevalence rates and serovar distributions of Chlamydia trachomatis cervical infections were investigated in two different groups of women. Group I consisted of 393 asymptomatic young women (aged 17 to 30 years) who were invited to participate in a C. trachomatis screening program. Group II consisted of 734 randomly selected patients (aged 17 to 68 years) attending an inner-city gynecological outpatient clinic. C. trachomatis was detected in cervical scrapes by PCR specific for endogenous plasmid. These plasmid PCR-positive samples were subsequently subjected to genotyping by C. trachomatis-specific omp1 PCR-based restriction fragment length polymorphism analysis (J. Lan, J. M. M. Walboomers, R. Roosendaal, G. J. van Doornum, D. M. MacLaren, C. J. L. M. Meijer, and A. J. C. van den Brule, J. Clin. Microbiol. 31:1060-1065, 1993). The overall prevalence rates of C. trachomatis found in patients younger than 30 years were 9.2 and 11.8% in groups I and II, respectively. A clear age dependency was seen in group II, with the highest prevalence rate (20%) found in patients younger than 20 years, while the rate declined significantly after 30 years of age (5.9%). In women younger than 30 years, the genotyping results showed that serovars E, I, and D (in decreasing order) were frequent in group I, while serovars F, E, and G (in decreasing order) were predominantly found in group II. The study shows that C. trachomatis infections are highly prevalent in asymptomatic young women. The different serovar distributions found most likely reflect the different compositions of the study groups, but additional analysis of the case histories of individual patients suggests that certain serovars might be associated with symptomatic (i.e., serovar G) or asymptomatic (i.e., serovars D and I) infections.

Human papillomavirus detection in high-grade squamous intraepithelial lesions. Comparison of hybrid capture assay with a polymerase chain reaction system

The validity of human papillomavirus (HPV) detection using the hybrid capture assay (HCA) was compared with the polymerase chain reaction (PCR) in 38 patients with high-grade squamous intraepithelial lesions (HSILs). HCA and PCR showed 84% agreement for HPV detection. HCA missed a significant higher proportion of HSIL compared with PCR (21% vs. 5%; P = .04). Thus, the sensitivity of HCA should be increased before this test can be recommended for HSIL.

Integrated human papillomavirus type 16 and loss of heterozygosity at 11q22 and 18q21 in an oral carcinoma and its derivative cell line

A human papillomavirus (HPV) type 16 containing oral squamous cell carcinoma cell line 93VU147T at early passage was demonstrated to match its primary tumor with regard to HPV status and loss of heterozygosity at loci potentially involved in HPV-mediated carcinogenesis. DNA in situ hybridization of the cell line and the primary tumor revealed the presence of HPV 16 DNA clonally associated with the neoplastic cells. One- and two-dimensional Southern blot hybridization suggested HPV 16 to be integrated in the host genome at over hundred copies/cell. An identical restriction enzyme profile was observed for the tumor and the cell line. Viral DNA integration was confirmed by fluorescence in situ hybridization on metaphase spreads of the cell line, which revealed six stained loci comprising one at 15q14-15 and five at cytogenetically unidentifiable chromosomes. In addition, the tumor and the cell line displayed mRNA expression of the E6/E7 region encoding the viral oncoproteins, as determined by reverse transcription-PCR. Northern blot analysis of the cell line revealed three major and three minor transcripts harboring E6/E7 sequences. Both the primary tumor and cell line showed loss of heterozygosity at the 11q22 (D11S35) and 18q21 (DCC) loci. These data support a role for HPV 16 in the development of a subset of oral cancers, presumably in concert with loss of function of tumor suppressor genes at 11q and 18q.

CD30 expression in normal and neoplastic lymphoid tissue: biological aspects and clinical implications

CD30 expression is found on Hodgkin and Reed-Sternberg cells, anaplastic large cell lymphoma cells and on activated B or T lymphocytes. Recently CD30 was shown to be a transmembrane receptor that is significantly homologous to the tumor necrosis factor receptor (TNFR) family. Ligands for most members of this family, including CD30, have now been identified. This review summarizes the role of the different TNFR family members in lymphocyte proliferation and differentiation in an attempt to understand more clearly the role of CD30 expression in the pathogenesis and clinical behavior of non-Hodgkin's lymphomas. We state that CD30 expression is of prognostic relevance in primary cutaneous and nodal T cell lymphomas in contrast to the absence of clinical relevance of CD30 expression in B cell lymphomas.

Genotyping of Chlamydia trachomatis serovars derived from heterosexual partners and a detailed genomic analysis of serovar F

OBJECTIVE

To investigate C trachomatis serovars in contact-traced heterosexual partners.

METHODS

Urogenital Chlamydia trachomatis isolates (n = 112) derived from 35 heterosexual patients (index patients) and their 37 chlamydia positive partners (contact patients) were differentiated into serovars by genotyping with restriction fragment length polymorphism (RFLP) analysis of the PCR amplified omp1 gene. In order to investigate whether different strains within the frequently prevalent serovar F were transmitted, two pairs of serovar F (n = 4) were further analysed by genomic DNA fingerprinting with arbitrary primer PCRs (AP-PCRs).

RESULTS

Identical C trachomatis serovars were found in 31 of the 35 pairs, serovars E, F, D, and G being most prevalent. In the remaining four pairs different serovars (either D, E, F or G) were found between the index and the contact patients. By AP-PCR analysis the strains of serovar F were found to be identical between the index and the contact patients, but were different between the two pairs in all AP-PCRs used.

CONCLUSION

A majority of heterosexual partners, once traced positive for C trachomatis infections, are infected with identical serovars. Identical strains of serovar F found in partners as found by DNA fingerprinting confirms the sexual transmission of C trachomatis.

Detection of heterogeneous Epstein-Barr virus gene expression patterns within individual post-transplantation lymphoproliferative disorders

Using RT-PCR analysis of Epstein-Barr virus (EBV) latent gene transcription in EBV-harboring cell lines (JY and RAJI) and in post-transplantation lymphoproliferative disorders (PT-LPDs), we detected transcription of all tested latent genes (EBNA1, EBNA2, LMP1, LMP2A, and BARF0) in all cases, suggesting the presence of similar EBV expression patterns in both PT-LPDs and cell lines. In addition, the detection of immediate early (ZEBRA) and early gene (BHRF1) transcripts in cell lines and PT-LPDs indicates that activation of the virus lytic cycle occurs. To investigate EBV expression patterns at the single-cell level, a combination of immunohistochemistry and RNA in situ hybridization (including double-staining procedures) was used. In the JY and RAJI cell lines, the latency type 3 expression pattern was detected in 80 to 90% of the cells as shown by the co-expression of EBNA2 and LMP1. In contrast, in the three PT-LPDs that could be analyzed by double staining, cells expressing both EBNA2 and LMP1 were rarely detected. A mixture of at least three different cell populations were identified: (1) cells exclusively expressing EBER1/2 and EBNA1 (latency type 1); (2) cells expressing EBER1/2, EBNA1, and LMP1 (latency type 2); and (3) cells expressing EBER1/2, EBNA1, and EBNA2 in the absence of LMP1. Activation of the lytic cycle was observed in a small minority of cells, as demonstrated by detection of ZEBRA and EA-D in all cases and GP350/220 in two cases. Thus, in contrast to EBV-transformed cell lines, the observed EBV gene expression pattern in PT-LPDs reflects a mixture of multiple EBV-harboring subpopulations expressing different subsets of EBV-encoded proteins. These data indicate that the operational definitions of EBV latencies in vitro cannot easily be applied to PT-LPDs but that a continuum of different latency expression patterns can be detected at the single cell level in these lymphomas with, in a small minority of cells, progression to the virus lytic cycle.

Chlamydia trachomatis and ectopic pregnancy: retrospective analysis of salpingectomy specimens, endometrial biopsies, and cervical smears

AIMS

To examine the role of Chlamydia trachomatis in ectopic pregnancy by detection of DNA in archival salpingectomy specimens, and in their preceding cervical specimens and endometrial biopsies, by using the polymerase chain reaction (PCR).

METHODS

Archival paraffin embedded salpingectomy tissues (n = 48) from 37 women with ectopic pregnancy were examined for the presence of C trachomatis plasmid and omp1 DNA by PCR. In addition, preceding cervical specimens (n = 58) stored either as cervical cell suspensions or as archival cervical smears, and preceding endometrial biopsies (n = 18), taken 0-5.8 years before the ectopic pregnancy, were examined by PCR for the presence of C trachomatis.

RESULTS

C trachomatis DNA was detected in only one of the 48 salpingectomy specimens from 37 women. However, in six of the 37 women, C trachomatis DNA was detected in the genital specimens (cervix and/or endometrial) taken before salpingectomy. C trachomatis infections were mostly found in endometrial or cervical specimens taken more than three years before ectopic pregnancy. No chlamydial DNA was found in endometrial or cervical specimens taken at the same time of the ectopic pregnancy.

CONCLUSIONS

Although no C trachomatis DNA was found in salpingectomy specimens, several women with ectopic pregnancy had C trachomatis infections in endometrial and cervical specimens in the past. This suggests that at least in these cases the ectopic pregnancy is a late post-inflammatory complication of an ascending C trachomatis infection resulting in a scarred fallopian tube.

BHRF1, the Epstein-Barr virus (EBV) homologue of the BCL-2 protooncogene, is transcribed in EBV-associated B-cell lymphomas and in reactive lymphocytes

BHRF1, one of many Epstein-Barr virus (EBV)-encoded proteins, shows strong functional homology to the human bcl-2 proto-oncogene product, a protein involved in the pathogenesis of a subset of B-cell lymphomas, ie, follicle center cell lymphomas (FCCL). We have investigated the presence of possible latent and lytic transcripts of BHRF1 using a reverse transcriptase-polymerase chain reaction (RT-PCR)-based assay in a group of EBV-associated B-cell lymphomas in patients with (N = 5) or without overt immunodeficiency (N = 4), in T-cell lymphomas (N = 9), and in cases of Hodgkin's disease (N = 6). BHRF1 transcription was found consistently in EBV-associated (ie, diffuse EBER 1/2-positive) B-cell lymphomas in patients with or without immune deficiency, whereas in EBV-associated T-cell lymphomas or in EBV-associated Hodgkin's disease, BHRF1 transcription was only detected in two T-cell lymphomas and one case of Hodgkin's disease, which also harbored EBER 1/2-positive reactive cells. Moreover, weak BHRF1 signals were found in two T-cell lymphomas where EBER 1/2 expression was detected mainly in sporadic reactive lymphocytes and in one reactive tonsil with sporadic EBER 1/2-positive lymphocytes. BHRF1 transcripts were found to be generated by the C or W promoter (associated with viral latency) and/or by the H promoter (associated with the virus lytic cycle). In all cases with H promoter-derived BHRF1 transcripts, transcripts encoding ZEBRA were also detected, suggesting a reactivation of the virus lytic cycle. Analysis of other EBV genes revealed transcription of BARFO in all tested EBV-harboring tissues. Transcription of EBNA1 and LMP1 was usually detected, whereas EBNA2 transcription was found exclusively in B-cell lymphomas in immunocompromised patients. These data demonstrate that BHRF1 transcripts are exclusively found in EBV-associated B-cell lymphomas. When BHRF1 transcripts are detected in T-cell lymphomas or in Hodgkin's disease, it is probably due to the presence of reactive EBER 1/2-positive lymphocytes. The consistent transcription of BHRF1 in EBV-associated B-cell lymphomas suggests a possible pathogenic role for this gene product in EBV-positive B-cell lymphomas analogous to bcl-2.

Human papillomavirus in false negative archival cervical smears: implications for screening for cervical cancer

AIM

To assess the value of detecting human papillomavirus (HPV) DNA in false negative archival cervical smears in population based screening programmes for cervical cancer.

METHODS

Cytomorphologically classified false negative archival Pap smears (n = 27) taken from 18 women up to six years before cervical cancer was diagnosed were blindly mixed with 89 smears from hospital patients with a variety of gynaecological complaints and tested for HPV by the polymerase chain reaction (PCR). Corresponding cervical cancer biopsy specimens were also available for HPV analysis. Neither the examining cytopathologist nor the molecular biologist was aware of the study design.

RESULTS

HPV DNA was detected in the smears of 16 patients with cervical cancer missed previously by cytology. HPV 16 and 18 were found predominantly in those smears taken up to six years before the diagnosis of cervical cancer. The smears of the two remaining patients were reclassified as inadequate for cytology or contained no suitable DNA for PCR. In 15 patients the same HPV type could be found in the smears and the cervical cancer biopsy specimens.

CONCLUSIONS

The results indicate that high risk HPV types can be detected in archival smears classified as false negative on cytology and that cytological screening errors may be reduced if combined with PCR testing for HPV.

Processing of long-stored archival cervical smears for human papillomavirus detection by the polymerase chain reaction

The efficiency of a freeze-thaw method, a proteinase K/Tween 20 lysis method and a guanidinium isothiocyanate/silica beads method for DNA extraction from fixed and Papanicolaou-stained cells from the cervical cancer cell line Siha was measured by beta-globin polymerase chain reaction (PCR). The GTC/silica beads method, which appeared superior, revealed a human papillomavirus (HPV) general primer-mediated PCR sensitivity of 50-500 copies of HPV 16 per sample using dilutions of fixed and stained Siha cells. Application to archival cervical smears (n = 116) revealed that the yield and size of amplifiable DNA decreases with storage time. The longer the storage time, the more repetitions of the whole procedure, including the lysis step, were required to extract sufficient amplifiable DNA. In this way, an overall beta-globin PCR positivity for 98% of the smears was reached. Further analysis revealed that a maximum size of 200 bp could be amplified from smears stored for up to 9 years. The method was validated by demonstrating by PCR the same HPV types in archival smears and corresponding cervical biopsies of cervical cancer patients. In conclusion, the GTC/silica beads method appears suitable to process archival cervical smears for HPV detection by PCR. provided that stepwise adjustments are made until beta-globin PCR positivity is obtained and primers are chosen which amplify a maximum of about 200 bp.

Nasal T-cell lymphoma: a clinicopathological and immunophenotypic analysis of 13 cases

Thirteen cases of nasal lymphomas with T-cell or natural killer (NK)-cell phenotype were studied, with attention to clinical presentation and follow-up, the presence of Epstein-Barr virus (EBV) using in situ hybridization (EBER), the immunophenotype, and the presence of cytotoxic granules. All but two patients presented with stage I disease. In three cases local progression resulted in involvement of the central nervous system. When dissemination occurred, this was predominantly to extranodal localizations, in two cases to the skin. Response to therapy was highly variable, but patients treated with radiotherapy with or without additional chemotherapy had a better prognosis than patients treated with initial chemotherapy alone. All lymphomas were associated with EBV, and most cases showed cytotoxic features, ten of which were CD56 positive. In eight cases a T-cell origin was proven, but in five cases a possible NK-cell origin could not be excluded. No clinical differences were seen between true T-cell lymphomas and possible NK-cell neoplasms. Nasal T-cell lymphomas should be considered as a distinct clinicopathological entity, strongly associated with EBV, and with cytotoxic features in most cases. No prognostic parameters were detected to predict dissemination and response to therapy.

Neuroendocrine neoplasms of the larynx. Importance of the correct diagnosis and differences between atypical carcinoid tumors and small-cell neuroendocrine carcinoma

Findings in the present study have confirmed that the diagnosis of neuroendocrine tumors of the larynx (NETL) requires that a panel of neuroendocrine markers and electron microscopy be performed. This means that the clinician must be aware of the clinical presentations of such patients and should send fresh biopsy specimens to the clinical laboratory for optimal tissue studies. As shown in this study, the possibility of misdiagnosis of an atypical carcinoid tumor (ACT) is rather high. In establishing a diagnosis, a part of the material should be fixed for conventional histology, a part for immunohistochemistry and a part for electron microscopy. The correct diagnosis of NETL is obviously of great importance for subsequent treatment and prognosis. Patients with the diagnosis of ACT of the larynx require surgical treatment. Our findings also show that small-cell neuroendocrine carcinomas of the larynx should be considered to be a disseminated disease at initial presentation. A metastatic workup is necessary, but radical surgical procedures should be avoided. The combination of radiotherapy and chemotherapy is always indicated.

Distribution of OV-TL 3 and MOv18 in normal and malignant ovarian tissue

AIMS

To analyse the distribution of OV-TL 3 and MOv18 in normal ovarian tissue to determine which antibody is most suitable for (radio)immunotherapy of ovarian carcinoma.

METHODS

The distribution of OV-TL 3 and MOv18 was determined using immunohistochemistry and flow cytometry.

RESULTS

Epithelial and other cells in many tissues, and leucocytes in peripheral blood, bone marrow and spleen stained positively with OV-TL 3. The staining pattern of MOv18 in normal tissues was more restricted and was confined to epithelial cells in the lung, kidney, pancreas, salivary gland, ovary, Fallopian tubes, and cervix. Reactivity was also observed with pneumocytes in the lung, tubuli in the kidney, acinar cells in the salivary gland and pancreas, in the placenta, and with Kupffer cells in the liver. The staining pattern of chimeric MOv18 was identical with the murine form. OV-TL 3 and MOv18 reacted with 100% and 98% (45/46) of the 46 tested epithelial ovarian cancers, respectively. In ovarian carcinoma tissue homogeneous staining of epithelial cells was observed with OV-TL 3 and more heterogeneous staining with MOv18. In 12 and nine patients, respectively, a difference in staining intensity for OV-TL 3 and MOv18 was observed between various tumour samples from the same patient.

CONCLUSION

MOv18 has greater therapeutic potential because of its restricted reactivity with normal tissues and especially, in contrast to OV-TL 3, its lack of reactivity with haematopoietic cells.

Epstein-Barr virus (EBV) in extranodal T-cell non-Hodgkin's lymphomas (T-NHL). Identification of nasal T-NHL as a distinct clinicopathological entity associated with EBV

T-cell Non-Hodgkin's lymphomas (T-NHL) can be defined as clonal malignant proliferations related phenotypically and functionally to normal T-cell populations of the lymphoid tissue. There is increasing evidence that T-NHL with similar morphology but originating from different sites differ in their clinical behaviour, immunophenotypic features, oncogene expression and relation with oncogenic viruses such as HTLV-I and EBV. Indeed, it has been shown that the prevalence of EBV in T-NHL is related to the site of origin. Thus, EBV was found in nearly all nasal T-NHL but only in a proportion of primary nodal, lung, gastrointestinal and Waldeyer's ring T-NHL while it was undetectable in most primary cutaneous T-NHL. Besides their constant association with EBV, nasal T-NHL display peculiar clinical, histological, immunophenotypic and genotypic features. They present clinically as lethal midline granuloma and histologically as pleomorphic malignant tumours variably associated with angiocentricity, angioinvasion and necrosis. Moreover, they frequently exhibit extensive loss of T-cell antigens, including CD3 and TCR alpha beta and gamma delta proteins, usually express the Natural Killer (NK)-related CD56 antigen and frequently show absence of clonal rearrangements of TCR beta, gamma and delta loci. Therefore, among T-NHL, nasal T-NHL can be regarded as a distinct clinicopathologic entity associated with EBV, which could be derived either from immature T-cells or from NK cells.

HPV prevalence in cytomorphologically normal cervical scrapes of pregnant women as determined by PCR: the age-related pattern

Diverging data exist on human papillomavirus (HPV) prevalence in cytomorphologically normal scrapes during pregnancy. The prevalence of HPV was therefore investigated by polymerase chain reaction method (PCR) in cytomorphologically normal scrapes of 709 pregnant women and 3,948 non-pregnant women visiting the same hospital during the same time period. The prevalence of all types of HPV among pregnant women was 9.6% (68/709) and the high risk HPV types of 16 and 18 were found in 3.1% (22/709). In the non-pregnant women the prevalence of all types of HPV was 10.9% (432/3,948) with 2.9% (116/3,948) HPV types 16 and 18. The highest prevalence of HPV was present in women at younger ages in both groups. With increasing age the prevalence declines from about 19% (15-25 yrs) to 5% (40-49 yrs). The age-adjusted odds ratio of prevalence of all types of HPV in pregnant versus non-pregnant women was 0.73 (95% CI 0.56-0.96, P = 0.025) and statistically significant. When HPV types 16 and 18 were considered, significant differences were not found. HPV of all types and types 16/18 prevalence was higher in the second half of pregnancy than in the first part but did not reach statistical significance. High HPV copy numbers in the scrapes were found during the first half of the pregnancy and not during the second half using a semi-quantitative HPV 16/18 PCR detection method. Since the difference in HPV prevalence between non-pregnant and pregnant women is very small, it is concluded that HPV prevalence in cytomorphologically normal smears is hardly influenced by pregnancy.

The drug resistance-related protein LRP is the human major vault protein

Multidrug-resistant cancer cells frequently overexpress the 110-kD LRP protein (originally named Lung Resistance-related Protein). LRP overexpression has been found to predict a poor response to chemotherapy in acute myeloid leukaemia and ovarian carcinoma. We describe the cloning and chromosome localization of the gene coding for this novel protein. The deduced LRP amino acid sequence shows 87.7% identity with the 104-kD rat major vault protein. Vaults are multi-subunit structures that may be involved in nucleo-cytoplasmic transport. The LRP gene is located on chromosome 16, close to the genes coding for multidrug resistance-associated protein and protein kinase C-beta, and may mediate drug resistance, perhaps via a transport process.

Expression of bcl-2 protein and transcription of the Epstein-Barr virus bcl-2 homologue BHRF-1 in Hodgkin's disease: implications for different pathogenic mechanisms

Epstein-Barr virus (EBV) is frequently found in Hodgkin and Reed-Sternberg cells in Hodgkin's disease. Epstein-Barr virus has transforming properties in vitro and might be involved in the pathogenesis of certain types of Hodgkin's disease. One of the possible mechanisms is the upregulation of the human proto-oncogene bcl-2 by the latent membrane protein 1 of EBV in vitro. Another possibility might be the expression of the viral 'bcl-2 homologue' BHRF-1. In the present study of 64 cases of Hodgkin's disease we investigated the expression of bcl-2 at the protein level in relation to the presence of EBV. Moreover, in 10 EBV positive cases we investigated, the expression of the bcl-2 homologue, BHRF-1, by reverse-transcriptase PCR. bcl-2 was detected in 14 of 22 (64%) EBV positive and in 37 of 42 (88%) EBV negative cases. In 17 of 22 (77%) EBV positive cases Reed-Sternberg cells were negative (n = 8) or expressed the bcl-2 protein in a very low percentage ( < 5%) of cells (n = 9), whereas in 20 of 42 (43%) of the EBV negative cases the majority ( > 50%) of the neoplastic cells were bcl-2 positive. Using the reverse-transcriptase PCR with primers amplifying transcripts of BHRF-1 we were able to detect BHRF-1 transcripts in only one of the 10 tested cases of EBV positive Hodgkin's disease. Our data indicate that in EBV positive Hodgkin's disease growth advantage of Reed-Sternberg cells is not obtained by upregulation of bcl-2 or by the EBV homologue BHRF-1.

The presence of persistent high-risk HPV genotypes in dysplastic cervical lesions is associated with progressive disease: natural history up to 36 months

To evaluate the clinical significance of HPV genotyping for the prediction of progressive cervical intraepithelial neoplasia (CIN) in women with cytomorphologically abnormal smears, a prospective, blind, non-intervention study was performed. A total of 342 patients screened with cytomorphologically abnormal cervical smears were monitored every 3-4 months by cervical cytology, colposcopy and HPV testing using PCR. Women with progressive CIN disease were defined as patients developing lesions with a colposcopic impression of CIN III over more than 2 quadrants or resulting in a cytological smear equivalent to Pap 5. These patients were subsequently treated according to standard procedures. If any doubt arose about the true status of the patients (n = 75) these patients were censored and biopsied. The mean follow-up time was 16.5 months (range 3-36 months). Nineteen women showed progressive CIN disease and all appeared to be continuously HPV-positive from the start of the study. At biopsy, all these patients were histologically classified as CIN III. Seventeen of these women were positive for high-risk HPV types. Two cases were classified as still unidentified HPV. No progression was seen in the absence of HPV DNA or in the presence of low-risk HPV types. In life-table analysis the cumulative rate of progressive, histologically verified CIN disease was 17% after 36 months. Further analyses showed that other risk factors such as age, sexarche, number of sexual partners or smoking hardly influenced the effect of HPV on progression. The results show that the continuous presence of high-risk HPV types in women with cytomorphologically abnormal smears is a strong marker for progressive CIN disease.

Immunohistochemical demonstration of different latent membrane protein-1 epitopes of Epstein-Barr virus in lymphoproliferative diseases

AIM

To compare the immunoreactivity of monoclonal antibodies S12 and CS1-4, which recognise different epitopes of the Epstein-Barr virus (EBV) latent membrane protein-1 (LMP-1), in EBV associated benign and malignant lymphoproliferative disorders and control tissues processed using different methods.

RESULTS

Both monoclonal antibodies gave comparable results on frozen tissue sections and formalin fixed, paraffin wax embedded samples from cases with Hodgkin's disease and infectious mononucleosis. In all cases S12 stained more cells than CS1-4. For EBV associated B and T non-Hodgkin's lymphomas, frozen tissue sections yielded better LMP-1 staining results than formalin fixed material. Again, in all these cases S12 stained more cells and gave stronger results than CS1-4. For EBV negative tissues, both monoclonal antibodies showed cross-reactivity with melanocytic-like cells in the basal cell layer of the skin, synaptophysin-like staining in layers three and four of the cortex of the brain, and myelin-like staining in peripheral nerves and peripheral ganglion cells. Staining with S12 was always much stronger. Moreover, in contrast to CS1-4, S12 stained pancreatic islands in formalin fixed material but not in frozen tissue sections and sporadically stained solitary epithelial cells in the large bowel especially in formalin fixed tissue sections. CS1-4 also cross-reacted with myoepithelial cells around hair follicles and other adnexa of the skin.

CONCLUSION

The results indicate that for optimal detection of LMP-1, S12 yields better results than CS1-4 and that tissue processing is very important especially when B and T non-Hodgkin's lymphomas are examined.