Victor Bakels

A two-step polymerase chain reaction (PCR) procedure was used as a new screening strategy for the detection of human papillomavirus (HPV) genotypes in cervical scrapes omitting prior DNA extraction. Sample preparation consisted of a freeze-thaw step followed by boiling the cells before the PCR mixture was added. This pretreatment was as efficient and reproducible for HPV DNA amplification as DNA purification. By using crude cell suspensions, a prescreening of the samples with the general primer-mediated PCR method (GP-PCR) was performed to detect a broad spectrum of sequenced and still unsequenced HPV types at the subpicogram level. HPV-containing scrapes by GP-PCR were subjected to HPV 6, 11, 16, 18, 31, and 33 type-specific PCR (TS-PCR) to identify the sequenced HPV types. This direct GP/TS-PCR method was tested on a large group of cervical scrapes (n = 459) from women visiting a gynecologic outpatient clinic. The results were compared with HPV data obtained by a method using modified filter in situ hybridization and TS-PCR in which the PCR was mainly used to confirm HPV positivity. A substantially higher HPV prevalence rate was found by direct GP/TS-PCR strategy. The results indicate that GP/TS-PCR is a rapid, sensitive, and reliable detection method for HPV in cervical scrapes. The easy performance on crude cell suspensions makes this strategy applicable for large HPV-screening programs.

Differentiation between cutaneous pseudo-T-cell lymphomas and cutaneous T-cell lymphomas (CTCLs) may be extremely difficult. In this study, it was investigated whether demonstration of an aberrant phenotype and detection of clonal T-cell receptor gamma (TCR gamma) gene rearrangements can be used as additional differential diagnostic criteria. Immunohistochemical studies and TCR gamma gene rearrangement analysis using a polymerase chain reaction with primers specific for V gamma 1-8 and V gamma 9 gene segments in combination with denaturing gradient gel electrophoresis (PCR/ DGGE) were performed on frozen material of 11 pseudo-T-cell lymphomas and 17 CTCLs, including 9 cases of mycosis fungoides (MF) and 8 pleomorphic CTCLs. Clonal TCR gamma gene rearrangements were found in 66% of patch/plaque-stage MF and 100% of tumor-stage MF and pleomorphic CTCL, but not in any of 10 pseudo-T-cell lymphomas studied. Aberrant expression of CD2, CD3, and/or CD5 antigens was noted in 3 of 6 (50%) cases of patch/plaque-stage MF, all three cases of tumor-stage MF, and 5 of 8 (62%) pleomorphic CTCLs, but not in any of the 11 pseudo-T-cell lymphomas. Moreover, in pseudo-T-cell lymphomas exhibiting a nodular or diffuse growth pattern, a considerable admixture with reactive CD8+ T cells (15 to 60%), B cells (up to 20%), and macrophages was a characteristic finding. In conclusion, the results of this study suggest that demonstration of clonal TCR gene rearrangements and an aberrant phenotype, as well as demonstration of many admixed CD8+ T cells and B cells can be considered as useful additional criteria in the differentiation between pseudo-T-cell lymphomas and CTCLs.

AIMS: Differentiation between actinic reticuloid and cutaneous T cell lymphoma can be extremely difficult. Demonstration of clonal T cell receptor (TCR) gene rearrangements has been suggested as a potential diagnostic criterion, but the results obtained thus far have been conflicting. This study investigated whether TCR gamma gene rearrangement analysis, using polymerase chain reaction (PCR) in combination with denaturing gradient gel electrophoresis (DGGE) and immunohistochemistry, can serve as a diagnostic criterion. METHODS: PCR/DGGE was performed on skin, peripheral blood mononuclear cells, and/or lymph nodes of seven patients with actinic reticuloid, 11 patients with Sézary syndrome, and 15 patients with a benign form of erythroderma. The results of PCR/DGGE and Southern blot analysis of TCR beta gene rearrangements were compared. In addition, CD4:CD8 ratios in skin and peripheral blood samples were investigated. RESULTS: Clonal T cell populations were detected in 19 of 21 samples obtained from patients with Sézary syndrome but were not detected in any of the 12 samples from patients with actinic reticuloid. Clonal T cells were detected in the peripheral blood of only one of 15 patients with a benign form of erythroderma. PCR/DGGE and Southern blot analysis gave concordant results in 28 of 29 samples. Immunophenotypic analysis demonstrated increased proportions of CD8+ T cells in skin (seven of seven cases) and peripheral blood (four of seven cases) of patients with actinic reticuloid. CONCLUSION: The results of this study demonstrate that gene rearrangement analysis, in combination with immunohistochemistry, may be an important adjunct in differentiating between actinic reticuloid and cutaneous T cell lymphoma. In patients suspected of having actinic reticuloid, application of both techniques is recommended.