Analysis of helper activity on pokeweed mitogen- and interleukin 2-driven immunoglobulin synthesis by neoplastic T4+ cells.

The neoplastic T cells of a series of seven patients with chronic T-cell neoplasia were tested for helper activity on pokeweed mitogen (PWM)-induced and interleukin 2 (IL-2)-induced Ig synthesis. The neoplastic T cells of all patients had a T3+4+8-11+I1- phenotype but differed in expression of the 3A1 antigen. The neoplastic T cells of three patients had helper activity on both PWM- and IL-2-driven Ig synthesis, and in addition produced IL-2 in response to PWM stimulation. Two of these patients had hypergammaglobulinemia. In contrast, the neoplastic T cells in the remaining four patients did not produce IL-2 and did not support PWM-driven Ig synthesis. The T4+ cells of these four patients, however, provided excellent helper activity on IL-2-driven Ig synthesis. These findings emphasize the role of IL-2 in T cell-dependent Ig synthesis and clearly show that IL-2 production is required for helper activity in the PWM-driven system. It is concluded that the combined use of PWM- and IL-2-driven Ig synthesis systems allows separate analysis of IL-2 production and T-helper activity in health and disease.

Stability and prognostic influence of FLT3 mutations in paired initial and relapsed AML samples.

In acute myeloid leukemia (AML), activating mutations in the fms-like tyrosine kinase 3 (FLT3) gene predict poor prognosis. We determined FLT3 internal tandem duplications (FLT3/ITD) and D835 point mutations in paired initial and relapse samples from 80 pediatric and adult AML patients. One D835 point mutation was found in an initial pediatric AML sample. Fms-like tyrosine kinase 3/ITDs were present in 21 initial and 22 relapse samples (26.3 and 27.5%, respectively). Interestingly, FLT3/ITD positivity was related to a significantly shorter time to relapse, most pronounced when the ITD-positive status was found at relapse (P<0.001). However, FLT3/ITD status changed between diagnosis and relapse in 14 cases. In four patients, the FLT3/ITD became undetectable at relapse in five patients FLT3/ITDs were only detected at relapse, and in five patients the length or number of FLT3/ITDs changed. Gain of FLT3/ITDs may suggest oligoclonality with selective outgrowth of the FLT3/ITD-positive clone, whereas losses may reflect ITDs in the more mature leukemic cells rather than in the leukemic stem cell, or, alternatively, that other genetic aberrations provided a greater selective advantage. Studying FLT3/ITD kinetics in minimal residual disease setting may provide some answers for the changes we observed. Fms-like tyrosine kinase 3/ITD is a relevant marker for prognosis, and remains an important target for therapeutic inhibition.

Differentiation and cell-type-restricted expression of HOXC4, HOXC5 and HOXC6 in myeloid leukemias and normal myeloid cells.

HOX genes have shown a lineage-specific expression in hematopoiesis and are suggested as being involved in the expression of certain adhesion molecules. Recently, we have demonstrated that HOXC4 and HOXC6, but not HOXC5, are expressed during lymphoid differentiation. Reports on the expression of these genes in myeloid leukemias and normal myeloid cells are still scarce. Therefore, we have investigated the expression of HOXC4, HOXC5 and HOXC6 in purified subpopulations of bone marrow in addition to 36 specimens of acute myeloid leukemias (AMLs), eight chronic myeloid leukemias (CMLs), several myeloid cell lines and cutaneous localizations of three myelomonocytic leukemias and one granulocytic sarcoma by RT-PCR and partly by RNA in situ hybridization (RISH). HOXC4 and HOXC6 transcripts were both detected by RT-PCR in 22/36 and 24/36 AMLs, respectively. The distribution of HOXC4 and HOXC6 gene expression over the different types of AML was largely similar and covered all types of AML. In contrast, HOXC5 gene expression was found in only 6/32 AMLs. Expression of HOXC5 was restricted to AMLs of the granulocytic (FAB M1-M3), early monocytic (FAB M4) and early erythroid (FAB M6) lineage. In general, except in one FAB M5b case, no expression of HOXC5 was found in AMLs derived from late stages of monocytic (FAB M5) and megakaryocytic (FAB M7) lineages. As for HOXC4 and HOXC6, expression of HOXC5 was absent in CMLs. Using RISH significant HOXC4, HOXC5 and HOXC6 expression was found in a number of additionally studied AML samples of different FAB classification (M2, M4, M5b and M5b), (M2 and M5b) (M2, M4, M5b), respectively. In tissue localizations of leukemias a different expression pattern of HOXC4, HOXC5 and HOXC6 was found. In contrast to mature leukemic stages of myeloid differentiation, these skin localizations of leukemias expressed HOXC5 and HOXC6. HOXC4 expression was found both in leukemic cells derived from peripheral blood and from cutaneous localizations. Besides HOXC4 expression in monocytes no expression of HOXC4, HOXC5 and HOXC6 was found in granulocytes and monocytes, colonies of growth factor-induced CD34+ bone marrow cells. In earliest CD34+/CD38low and high cell fractions of bone marrow only HOXC4 and in megakaryocytic cells both HOXC4 and HOXC6 were found. Thus, the expression patterns of these HOXC genes found in the limited number of cell fractions of normal bone marrow suggest that the expression patterns found in AMLs and CMLs might reflect the normal situation. Furthermore, the presence of HOXC5 and HOXC6 expression specifically in skin infiltrates of late differentiation stages of myeloid leukemias, suggests an additional role for these genes in the positioning of these myeloid cells in skin tissue.

Molecular analysis of hematopoietic colonies derived from chronic myeloid leukemia patients: interphase fluorescence in situ hybridization compared with RT-PCR.

In this study we compared interphase fluorescence in situ hybridization (I-FISH) with reverse transcription polymerase chain reaction (RT-PCR) for the molecular analysis of hematopoietic colonies derived from patients with chronic myeloid leukemia (CML). Molecular analysis of individual colonies is often performed to monitor purging efficacy in CML. We harvested individual colony-forming unit granulocyte-macrophage (CFU-GM) colonies. One half was analyzed with I-FISH, for the presence of bcr-abl fusion gene. The other half was analyzed with RT-PCR for the presence of the bcr-abl mRNA. We wanted to address the following questions: (1) is the bcr-abl gene always expressed in CFU-GM colonies and (2) which technique has to be preferred to analyze individual CFU-GM colonies? In total, 133 colonies, derived from six CML patients, could be analyzed both with I-FISH and RT-PCR. We found a positive correlation in 89% of the cases: 118 colonies showed the same results with both techniques. However, 15 of the 106 I-FISH-positive colonies were negative in the RT-PCR. Serial analysis of the cDNA derived from 22 colonies showed in each round of amplification 21-29% RT-PCR-negative but I-FISH-positive colonies. However, all I-FISH-positive colonies showed at least one positive RT-PCR, either in the first, second or third round of amplification. These results indicate that the bcr-abl gene is probably always transcriptionally active in CFU-GM colonies. Reliable analysis with RT-PCR is possible but likely to generate false negative results. We conclude that: (1) I-FISH offers a reliable alternative to RT-PCR for analyzing individual hematopoietic colonies and (2) results obtained with RT-PCR should only be interpreted with caution.

Hypersensitivity of bcr-abl-positive progenitors to hyperthermia in patients with chronic myeloid leukemia.

In this study, we evaluated the effect of hyperthermia on hematopoietic progenitors from six chronic myeloid leukemia (CML) bone marrow (BM) samples at diagnosis and four peripheral blood stem cell (PBSC) samples from CML patients after stem cell mobilisation. CD34-positive cells, isolated from these samples, were incubated for 2 h at 37, 42 or 43 degrees C and were plated in the colony-forming unit granulocyte-macrophage (CFU-GM) and the long-term culture initiating cell (LTCIC) assay. To evaluate purging, individual colonies from these assays were analyzed for the presence of the bcr-abl gene with interphase fluorescence in situ hybridization (FISH) and/or RT-PCR. BM samples showed a significant higher sensitivity both at the CFU-GM and LTCIC level, after treatment at 42 degrees C, as compared to the control BM samples obtained from healthy volunteers. The four BM samples of CML patients with a low leukocyte number at diagnosis harbored a mixture of bcr-abl-negative and positive colonies and an increase in the percentage of bcr-abl-negative colonies was observed in all cases. CML patients with a high leukocyte count at diagnosis, however, showed only bcr-abl-positive progenitors even after hyperthermia. PBSCs showed a significant higher sensitivity at the LTCIC level but not at the CFU-GM level, after treatment at 42 degrees C, as compared to the control PBSC samples obtained from nonhematologic cancer patients. Molecular analysis of individual colonies demonstrated an increase of bcr-abl-negative progenitors after thermic treatment in two out of three samples. When comparing both stem cell sources, PBSCs showed a decreased thermic sensitivity as compared to the BM samples at the CFU-GM level, whereas at the LTCIC level an increased thermic sensitivity was observed, both for the controls and the CML samples. In conclusion, both for BM and PBSCs samples, CML progenitors are more sensitive to hyperthermia than control cells, especially at the LTCIC level. In agreement with these results, an increase of bcr-abl-negative progenitors in six out of seven samples could be demonstrated either at the CFU-GM level, LTCIC level or both. Hyperthermia should be explored further as a possible purging modality in CML.

Polyclonal expansion of T-cell receptor-gamma delta+ T lymphocytes associated with neutropenia and thrombocytopenia.

A patient with large granular lymphocyte (LGL) expansion (T-gamma lymphocytosis), neutropenia and thrombocytopenia was studied longitudinally. Analysis of peripheral blood mononuclear cells (PBMC) demonstrated an unusual large proportion of CD3+ T-lymphocytes expressing a gamma delta T-cell receptor (TcR-gamma delta). Immunofluorescence (IF) stainings with subset-specific monoclonal antibodies showed a fluctuating expansion of TcR-gamma delta+ T-cells expressing V gamma 9 and V delta 2 variable (V) gene segments. Biochemical characterization of PBMC showed the presence of a disulphide-linked TcR-gamma delta. TcR gene rearrangement studies on sorted TcR-gamma delta+ T-cells showed rearrangements of V gamma 9-J gamma 1.2 and V delta 2-J delta 1 V and joining (J) gene segments, thereby confirming the IF staining results. These data alone did not allow us to determine whether the TcR-gamma delta+ LGL expansion represented a polyclonal or monoclonal proliferation, because the combinatorial repertoire of TcR-gamma delta receptors is limited due to the availability of only a few V and J segments within the TcR-gamma and TcR-delta genes and because of the preferential usage of V gamma 9-J gamma 1.2 and V delta 2-J delta 1 rearrangements by TcR-gamma delta+ T-cells in blood of healthy individuals. We therefore used polymerase chain reaction (PCR)-mediated amplification of the TcR-gamma delta rearrangements, using specific V gamma 9, J gamma 1.2, V delta 2, and J delta 1 oligonucleotides to determine the junctional diversity of the TcR-gamma delta+ T-cell population. Sequence analysis of the PCR products obtained revealed a mixture of different junctional region sequences compatible with a polyclonal expansion. This is in contrast to the few reported TcR-gamma delta+ LGL and the majority of TcR-alpha beta+ LGL expansions, which appeared to consist of monoclonal proliferations.

Proteoglycans on bone marrow endothelial cells bind and present SDF-1 towards hematopoietic progenitor cells.

Recognition events between hematopoietic progenitor cells (HPC) and bone marrow endothelial cells (BMEC) initiate homing of HPC to the bone marrow. The chemokine SDF-1 is present on BMEC and plays a crucial role in bone marrow engraftment. We studied the role of proteoglycans (PGs) on BMEC in binding and presentation of SDF-1. SDF-1 mRNA was present in three human BMEC cell lines. Competition experiments showed that 125I-SDF-1 alpha binding to the BMEC cell line 4LHBMEC was inhibited by heparins, heparan sulfate (HS) intestinal mucosa, chondroitin and dermatan sulfate (CS/DS), but not by HS bovine kidney. Pretreatment of 4LHBMEC with glycosaminoglycan (GAG)-degrading enzymes or sodium chlorate demonstrated that SDF-1 bound to both HSPGs and CS/DSPGs in a sulfation-dependent manner, as determined with an SDF-1 antibody recognizing the CXCR4-binding site. 4LHBMEC bound four-fold more SDF-1 than HUVEC. Isolated endothelial PGs did not bind SDF-1 in a filter or microplate-binding assay, suggesting the necessity of membrane association. In flow adhesion experiments, endothelial arrest of CXCR4+ KG-1 and not of CXCR4- KG-1a cells increased significantly when SDF-1 was presented on 4LHBMEC. In conclusion, SDF-1 is produced by BMEC and binds to the BMEC cell surface via HS and CS/DS-GAGs, thereby presenting its CXCR4 binding site to HPC contributing to their arrest.

Diagnostic value of T-cell receptor beta gene rearrangement analysis on peripheral blood lymphocytes of patients with erythroderma.

Differentiation between Sézary's syndrome (SS) and benign forms of erythroderma may be extremely difficult. In this study T-cell receptor beta (TCR beta) gene rearrangement analysis was performed on peripheral blood lymphocytes (PBL) from 32 patients with erythroderma, including 10 patients with SS, three patients with another type of cutaneous T-cell lymphoma, and 19 patients with a benign form of erythroderma. The aim of this study was to define the sensitivity and specificity of this technique in the diagnosis of SS. Clonal TCR beta gene rearrangements were found in eight of 10 patients with SS, one T-CLL patient, one of two patients with erythrodermic mycosis fungoides, and only one of 19 patients from the benign group. In the two "false-negative" cases of SS clonal TCR beta gene rearrangements were detected in PBL obtained during follow-up. The results indicate that TCR beta gene rearrangement analysis on PBL is a sensitive and highly specific technique, that may contribute significantly to the differential diagnosis of patients with erythroderma. However, because both "false-positive" and "false-negative" results may occur, the results of gene-rearrangement analysis should always be considered in conjunction with clinical, histologic, and immunophenotypical data.

Expression of the homeobox gene HOXC4 in keratinocytes of normal skin and epithelial skin tumors is correlated with differentiation.

Homeobox (HOX) genes share a highly conserved 183-bp sequence. The encoded proteins are capable of binding to specific DNA sequences and functioning as transcription factors. HOX genes play a critical role in the temporal and spatial differentiation of cells during embryogenesis. In several adult tissues, HOX genes are expressed in a constant, tissue-specific pattern, whereas in malignant tumors of these tissues an altered expression pattern was found. We investigated the expression of HOXC4 in adult normal skin by reverse-transcription polymerase chain reaction and non-radioactive RNA in situ hybridization. Moreover, HOXC4 expression was studied in various epidermal neoplasms (solar keratosis, six specimens; Bowen's disease, four; squamous cell carcinoma, nine; basal cell carcinoma, three) by RNA in situ hybridization. HOXC4 was found to be expressed in the suprabasal layers of the epidermis in normal skin specimens and the adjacent non-lesional epidermis of all other specimens. Atypical keratinocytes of solar keratoses and Bowen's disease as well as basaloid cells of basal cell carcinomas were negative. In squamous cell carcinoma, well differentiated areas with keratinization showed HOXC4 expression, whereas poorly differentiated areas were negative. Immunostaining with an antibody against cytokeratin 10, a marker of epidermal differentiation, was performed. A good correlation between the distribution pattern of HOXC4 and cytokeratin 10 in the lesions examined was found. These results suggest that HOXC4 is expressed mainly in differentiated keratinocytes. Lack of differentiation (as in neoplastic cells) is accompanied by downregulation of HOXC4 expression.

Demonstration of clonal immunoglobulin gene rearrangements in cutaneous B-cell lymphomas and pseudo-B-cell lymphomas: differential diagnostic and pathogenetic aspects.

Twenty-five patients with a benign or malignant cutaneous B-cell lymphoproliferative disease, including seven cutaneous pseudo-B-cell lymphomas, eight primary cutaneous B-cell lymphomas (CBCL), and 10 secondary cutaneous B-cell lymphomas, were investigated for the presence of clonal immunoglobulin (Ig) gene rearrangements using Southern blot hybridization analysis. The selection of pseudo-B-cell lymphomas was based on the presence of polyclonal light-chain expression with immunohistochemical analysis. All cases of CBCL demonstrated monotypic light-chain expression or absence of detectable Ig on CD20+ B cells. Clonal rearrangements of one or more Ig genes were demonstrated in four of seven cases of cutaneous pseudo-B-cell lymphomas, six of eight cases of primary CBCL, and in all cases of secondary CBCL. The observation that cutaneous pseudo-B-cell lymphomas as defined by immunohistochemical criteria often contain occult monoclonal B-cell populations implies that differentiating between pseudo-B-cell lymphomas and CBCL is not always possible by means of gene-rearrangement analysis. These findings may support the concept that cutaneous pseudo-B-cell lymphomas and primary CBCL are part of a continuous and progressive spectrum of B-cell lymphoproliferative skin disorders.

Differences in cytokine mRNA profiles between premalignant and malignant lesions of the uterine cervix.

The aim of this study was to assess the expression of cytokine transcripts, reflecting the type of ongoing immune responses at the site of human papillomavirus (HPV) infection, in relation to the development of cervical neoplasia. To this end reverse transcription-polymerase chain reaction (RT-PCR) was performed for interferon (IFN) gamma, interleukin (IL)-2, IL-4, IL-5, IL-10, IL-12 (p35 and p40), and transforming growth factor (TGF beta 1) in snap-frozen cervical biopsies, which were tested for the presence of high risk HPV DNA and histologically classified from normal to invasive carcinoma (n = 40). IFN gamma, IL-10 and IL-12 (p35 and p40) transcripts were found to be expressed at significantly lower frequencies in invasive carcinoma as compared with premalignant biopsies (P = 0.006, P = 0.007 and P = 0.002, respectively). IFN gamma IL-10 mRNA were associated with the presence of the IL-12 p35 and p40 transcripts (P = 0.008 and P < 0.00001, respectively). These results are consistent with a locally reduced cellular (type 1) immunity correlating with HPV-induced invasive cervical carcinoma.

Remission of monoclonal chronic T-cell expansion associated with severe anemia.

A 49-year-old male with an 8 year history of lowered Hb level, granulocytopenia and fatigue presented in 1986 with progressive fatigue, a dramatically reduced Hb level (45 g/l) and an increased lymphocyte count (6.6 x 10(9)/l). Clinical picture and laboratory studies led to the diagnosis of chronic T lymphocytosis with expansion of CD8+ T cells expressing CD16 IgG Fc receptors (Fc gamma RIII). DNA analyzed with T-cell receptor (TcR) gamma and beta probes revealed extra rearranged bands representing a clonal expansion of T lymphocytes. These T lymphocytes expressed T-cell receptor alpha beta as evaluated by staining with monoclonal antibodies. Because of the severe progressive anemia the patient was transfused with packed red cells. He was then treated with cyclophosphamide. After one month of treatment the transfusions could be discontinued and two months later cyclophosphamide treatment was stopped because of normalized Hb level and lymphocyte counts. The patient remained in a hematologically stable condition, though a minor T-cell population representing the clonal expansion, an inverted CD4/CD8 ratio and low immunoglobulin levels persisted. This is the first report of regression of proven monoclonal CD8+ T gamma-cell expansion and the associated anemia following cyclophosphamide therapy. These observations implicate the expanded monoclonal CD8+ lymphocytes in the pathogenesis of the anemia and granulocytopenia.

Phenotypic and genotypic analysis of large-cell lymphomas, formerly classified as true histiocytic lymphoma: identification of an unusual group of tumors.

A group of 12 large-cell lymphomas, seen in the period January 1983 to January 1985 and then tentatively classified as histiocytic sarcomas/true histiocytic lymphomas (i.e. non B-, non T-cell lymphomas, with expression of some histiocytic markers) were restudied phenotypically with a much more extensive range of monoclonal and polyclonal antibodies. They were also genotypically analyzed with respect to rearrangements of genes coding for the immunoglobulin (Ig) heavy and light chains and the gamma and beta chains of the T-cell receptor (TCR). The combined results suggest that these "histiocytic sarcomas" represent a heterogeneous group of large cell lymphomas often with unexpected rearrangements (or lack of rearrangements) of either Ig and TCR genes and phenotypically with coexpression of "histiocytic" and B- or T-cell markers. Such coexpression may be regarded as a warning signal to expect unusual genotype. True histiocytic tumours apparently do exist, but are rare (one case in this study), and their diagnosis is very difficult.

Mobilization of hematopoietic progenitors in patients with chronic myeloid leukemia.

Although the mobilization and harvesting of Philadelphia chromosome-negative progenitors has been proven feasible by a number of groups, it is not clear which techniques should be used with regard to the monitoring of purging and evaluation of stem cell yield. Therefore, we isolated CD34-positive cells from leukapheresis samples of seven CML patients after induction therapy. These cells were analyzed using the colony-forming unit granulocyte-macrophage (CFU-GM) and long-term culture-initiating cell (LTCIC) assays. In addition, we analyzed frequency and clonogenicity of single stem cells using the LTCIC assay at limiting dilution. Individual colonies derived from these assays were subsequently analyzed for the presence of the bcr-abl gene with interphase fluorescence in situ hybridization (FISH) and for the presence of bcr-abl mRNA with RT-PCR. We compared these results with the cytogenetic analysis of the leukapheresis material. Molecular analysis of individual colonies correlated well with the results of cytogenetic analysis. However, in nine out of 18 samples, cytogenetic analysis exclusively demonstrated the presence of either Philadelphia chromosome-positive or -negative cells whereas with the molecular analysis of individual colonies tumor contamination or the presence of residual normal cells could be substantiated. We concluded that molecular analysis of individual colonies should be employed to further optimize induction protocols. With regard to stem cell mobilization we demonstrated that about 67 CFU-GM colonies and clusters were generated by one single LTCIC both for the CML samples and the samples obtained from patients with non-hematologic malignancy. This number is important since until now most centres use a number of four colonies and clusters generated by one LTCIC. Dividing the CFU-GM output in the LTCIC assay by four to determine LTCIC frequency could thus lead to an almost 20-fold overestimation of the LTCIC frequency. It is concluded that stem cell frequency analysis is an important tool with regard to the interpretation of mobilization protocols.

Storage of unprocessed G-CSF-mobilized whole blood in a modified Leibovitz's L15 medium preserves clonogenic capacity for at least 7 days.

Autologous stem cell transplantation using unprocessed, G-CSF-mobilized whole blood (WB) is a simple, cost-reducing procedure and supports high-dose chemotherapy regimens not exceeding 72 h. Thereafter, clonogenic capacity rapidly decreases if routine anticoagulants are used for storage. In order to increase clinical applicability, we investigated the requirements for optimal preservation of unprocessed WB for 7 days. During storage at 22 degrees C in CPDA-1, a decrease in pH was noted, which was at least partially responsible for the low recovery of clonogenic cells. Subsequently, WB cells were stored in various cell culture media (RPMI 1640, alpha-MEM, X-VIVO15, CellGro SCGM and Leibovitz's L15 medium) containing either serum, serum-free substitutes or no additives. Leibovitz's L15 showed significantly better CFU-GM recoveries than the other media. Using a calcium-free modification of L15 medium (added 3:10 to WB), 94 +/- 24% of CD34(+) cells, 41 +/- 14% of BFU-E, 56 +/- 17% CFU-GM and 90 +/- 14% of LTC-IC were preserved during storage for 7 days at 22 degrees C. Storage at 4 degrees C was also feasible, but showed less optimal recoveries of 52 +/- 29% (CD34), 32 +/- 10% (BFU-E), 13 +/- 7% (CFU-GM) and 58 +/- 9% (LTC-IC). The expression of CD38, Thy-1, c-kit, AC133, L-selectin and CXCR4 on CD34-positive cells remained unchanged. In conclusion, a modified Leibovitz's L15 medium better meets the metabolic requirements of a high-density cell culture and allows safe storage of G-CSF mobilized WB for at least 7 days. The results encourage further exploration of WB transplants stored for 7 days for clinical use.

Differentiation between actinic reticuloid and cutaneous T cell lymphoma by T cell receptor gamma gene rearrangement analysis and immunophenotyping.

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.

Frequency and prognostic significance of clonal T-cell receptor beta-gene rearrangements in the peripheral blood of patients with mycosis fungoides.

BACKGROUND: Previous studies have shown that peripheral blood involvement is a poor prognostic sign in patients with cutaneous T-cell lymphoma. However, evaluation of the results of these studies is difficult. In this study peripheral blood mononuclear cells from 45 patients with various stages of mycosis fungoides (MF) were investigated for the presence of clonal T-cell populations by T-cell receptor beta (TCR beta)-gene rearrangement analysis. RESULTS: Clonal TCR beta-gene rearrangements were found in five (11%) of 45 patients with MF, including one (3%) of 31 patients without MF and four (27%) of 15 patients with histologically confirmed lymph node involvement. With respect to skin stage, clonal T-cell populations were detected in one (4%) of 23 patients with plaque stage disease, two (10%) of 19 patients with tumor stage disease, and two (50%) of four patients with erythrodermic MF. In the group of patients with lymph node involvement the median survival of patients with detectable clonal T-cell rearrangements in the peripheral blood was much shorter (3 months) than that of patients without clonal rearrangements (16 months). CONCLUSIONS: The results of this study indicate that clonal TCR beta-gene rearrangements, as detected by Southern blot analysis, are uncommon in the peripheral blood of patients with MF, in particular in patients without histologically documented lymph node involvement. The presence of clonal T-cell populations in the peripheral blood of MF patients with lymph node involvement is usually associated with rapidly fatal disease.

Lack of granzyme expression in T lymphocytes indicates poor cytotoxic T lymphocyte activation in human papillomavirus-associated cervical carcinomas.

Changes in major histocompatibility complex (MHC) class I expression in neoplastic cells are frequently observed in human papillomavirus type 16 (HPV16)-associated cervical carcinomas. In order to investigate whether this affects cytotoxic T-cell (CTL) activation, 20 HPV16-positive cervical carcinomas with variable MHC expression were analyzed immunohistochemically for the expression of granzyme B and interleukin-2 receptor (IL-2R). The results revealed that most carcinomas show strong CD3+ T-lymphocyte infiltrates. In nine of these cases CD8+ cells outnumbered the CD4+ cells, whereas in the remaining cases equal amounts of CD4+ and CD8+ cells were found. Double staining revealed that CD3+ granzyme B+ cells were not detected in 19 out of 20 cervical lesions, whereas in one carcinoma an occasional cluster of granzyme B+ T cells was observed. Positive controls, including genital warts and renal allograft rejections, showed granzyme B+ T cells. In agreement with this observation was the extremely low frequency of IL-2R+ T cells in the carcinomas tested, while warts contained IL-2R+ lymphocytes. The data indicate that cytotoxic (CD8+) T cells in cervical carcinomas are not activated, as demonstrated by the lack of granzyme B and IL-2R expression in the T cells.

Quantification of biotinylated RNA probes for in situ hybridization using chemiluminescence.

For reliable detection of mRNA by non-radioactive in situ hybridization, calibration and standardization of the individual steps involved are essential. We describe a method that allows determination of the size and integrity as well as quantification of biotinylated RNA probes in a single experiment. Serial dilutions of biotinylated RNA probes generated by promoter-mediated in vitro transcription were size-separated by gel electrophoresis in the presence of known amounts of 5'-biotinylated oligomers which served as internal standard. Following immobilization onto nylon membranes and visualization by chemiluminescence, optical densities of probes and internal standards were measured by densitometry and analysed by linear regression. RNA probes complementary to the human homeobox genes HOX-C6, -C8 and -C9 were quantified. Four different 5'-biotinylated oligomers (20, 35, 50 and 75 bases) were tested as internal standards. Concerning the separation of probe and oligomer in the gel, transfer properties and efficiency of binding to the membrane, the oligomer of 35 bases was found to be the best internal standard with highest reproducibility. Comparison of probe concentration by spectrophotometry and the described method showed a good correlation, indicating that our method is a reliable assay for quantitative and qualitative control of biotin-labelled probes.