Human immunodeficiency virus-related lymphoma: relation between clinical features and histologic subtypes

PURPOSE

Non-Hodgkin's lymphoma occurs frequently in patients with human immunodeficiency virus (HIV) infection and acquired immunodeficiency syndrome (AIDS). We determined the association between the clinical and histologic features of HIV-related lymphoma.

SUBJECTS AND METHODS

We reviewed the medical records of 291 patients with noncerebral HIV-related lymphoma who had been treated in multicenter trials coordinated by the Groupe d'Etude des Lymphomes de l'Adulte between 1988 and 1997. This study was performed mainly before the availability of combination antiretroviral therapy.

RESULTS

The main histologic subtypes were centroblastic lymphoma in 131 patients (45%), immunoblastic lymphoma in 39 patients (13%), and Burkitt's lymphoma (including the classical form and the variant with plasmacytic differentiation) in 115 patients (40%). Burkitt's lymphoma was the most aggressive form, whereas immunoblastic lymphoma occurred in severely immunodeficient patients. Two-year survival after enrollment was 15% in immunoblastic lymphoma, 32% in Burkitt's lymphoma, and 31% in centroblastic lymphoma (P = 0.006), but multivariate analysis did not confirm the independent prognostic value of histologic subtype. Instead, five independent pretreatment factors increased the risk of mortality: age 40 years or older [relative risk (RR) = 1.5; 95% confidence interval (CI), 1.1 to 2.1; P = 0.005], elevated serum lactate dehydrogenase level (RR = 1.5; 95% CI, 1.1 to 2.1; P = 0.02), having a diagnosis of AIDS before lymphoma (RR = 1.8; 95% CI, 1.2 to 2.6; P = 0.006), CD4(+) cell count less than 100 x 10(6)/L (RR = 1.8; 95% CI, 1.3 to 2.6; P = 0.0004), and impaired performance status (RR = 2.4; 95% CI, 1.7 to 3.4; P <0.0001).

CONCLUSION

Several pretreatment characteristics of HIV-related lymphoma were linked to the histologic form, but HIV disease parameters other than those of lymphoma were the main determinants of outcome, so the histologic features of the lymphoma were not associated with prognosis.

The management of adult aggressive non-Hodgkin's lymphomas

Aggressive non-Hodgkin's lymphona include diffuse large B-cell lymphoma, anaplastic large cell lymphona, and different peripheral T-cell lymphomas. An international prognostic index has been developed including age, serum LDH, performance status, and extranodal involvement. For localized aggressive lymphoma, the preferred treatment is 3-4 CHOP and radiation therapy, with a cure rate of 70-80%. For disseminated aggressive lymphoma, current regimens have a cure rate of less than 40%. Innovative strategies, including dose escalation, autologus stem cell support, new drugs, and immunotherapy are being explored to improve these results.

Detection of the cell death-inducing protein BAK in Reed-Sternberg cells of Hodgkin's disease

The expression of the cell death-inducing protein, Bak, was investigated in 41 cases of Hodgkin's disease and was correlated with Epstein-Barr virus (EBV) status. Overall, Bak immunostaining was observed in 35/41 cases (85%). Among the 22 EBV-positive cases, 20 cases (91%) expressed Bak while 15/19 EBV-negative cases (79%) contained Bak-positive Reed-Sternberg cells. The expression of Bak, as assessed by the staining intensity and the numbers of positive tumor cells, varied greatly from case to case but was high in 6 cases (15%). Our findings show that, similar to Bax, a second apoptosis-inducing gene Bak is frequently expressed in Hodgkin's disease. Whilst Bak is suspected to protect cells immortalized by EBV from apoptosis, its expression in Hodgkin's disease appears to be unrelated to the EBV status of Reed-Sternberg cells. Moreover, the potential pro-apoptotic functions related to Bak and Bax in Hodgkin's disease might be surpassed by a stronger expression of anti-apoptotic molecules thus explaining tumor progression.

High Epstein-Barr virus serum load and elevated titers of anti-ZEBRA antibodies in patients with EBV-harboring tumor cells of Hodgkin's disease

Hodgkin's disease is commonly associated with EBV latent infection. The incidence of EBV reactivation (active infection or EBV infection with replicative cycle) was evaluated in a series of 30 patients with untreated Hodgkin's disease (except for one case with chronic lymphocytic leukemia) by quantitation of EBV DNA and titration of anti-ZEBRA antibodies in serum samples. DNA was detected in serum (>2.5 x 10(2) genomes/ml) in 15 of 30 patients and was more frequent in Hodgkin's disease with EBV-positive Reed-Sternberg cells (10/12) than in EBV-negative cases (5/18), (P< 0.01). Of interest was the demonstration that viremia correlated well with increased titers of anti-ZEBRA IgG and/or standard serological profiles of EBV reactivation (12/15), (P < 0.05). However the lack of EBV replicative cycle in Reed-Sternberg cells (negative for ZEBRA antigen and early antigen BHLF1) suggests that the viral replication occurs in a nonneoplastic cell compartment rather than in tumor cells. The measurement of EBV DNA loads and the titration of anti-ZEBRA antibodies shed new lights on the link between activation of EBV replication and Hodgkin's disease: these serological markers together with the determination of the EBV status of the tumor suggest that replication of the viral genome occurs with a decreased efficiency of the immune system, thus allowing progression of the tumor.

Expression of apoptosis regulatory proteins of the Bcl-2 family and p53 in primary resected non-small-cell lung cancer

Proteins of the Bcl-2 family as well as p53 are important regulators of apoptosis. Alterations in the expression of these proteins can contribute to the formation of cancer, as well as influence tumour response to chemo- and radiotherapy. We used antibodies specific for the human Bcl-2, Mcl-1, Bax, Bak and p53 proteins to examine the expression of these apoptosis-regulating genes in 49 archival specimens of patients with radically resected non-small-cell lung cancer (NSCLC). Tumour cells containing immunostaining for the antiapoptotic proteins Bcl-2 and Mcl-1 were present in 31% and 58% of the cases evaluated, respectively, whereas immunopositivity for the proapoptotic proteins Bax and Bak was found in 47% and 58% of the samples. p53 immunopositivity was detected in 61% of the samples. The expression of Bcl-2 and p53 and the expression of Mcl-1 and Bax showed a positive association (P = 0.02 and P = 0.06 respectively), whereas the expression of Bax was inversely related to p53 (P = 0.008). The expression of Bcl-2 had a negative influence on relapse-free survival in this population of primary resected NSCLC patients (P = 0.02). The expression of p53 and Bcl-2 was significantly associated with metastasis-free survival (P < 0.01). Only patients with p53-positive tumours developed metastases during the follow-up period. Our results establish the frequent expression of the Bcl-2 family proteins Bcl-2, Mcl-1, Bax and Bak in NSCLC. It can be expected that Bcl-2 family members have no straightforward impact on clinical outcome in this disease because their interactions in the regulation of apoptosis are complex.

Location of the BCR-ABL fusion gene on the 9q34 band in two cases of Ph-positive chronic myeloid leukemia

Two new variant Philadelphia (Ph) chromosomes with an aberrant location of the BCR-ABL fusion gene on 9q34 of the derivative 9 are reported. One presented cytogenetically as a standard t(9;22)(q34;q11), whereas the other was classified as an ins(9;22)(q34;q11.1q11.2) using the combined interpretation of cytogenic, FISH, and molecular data. The mechanisms of the two rearrangements are presented. It is suggested that the insertion has occurred in a single event in the patient with ins(9;22). In the patient with t(9;22), both a translocation and an insertion, occurring either sequentially or simultaneously, can account for the location of the BCR-ABL fusion gene on the derivative 9. A possible poor prognostic impact of this aberrant location of the BCR-ABL is also suggested by the clinical data reported in such patients.

Telomerase activity in reactive and neoplastic lymphoid tissues: infrequent detection of activity in Hodgkin's disease

We used the recently described sensitive and rapid detection assay called telomeric repeat amplification protocol (TRAP) to detect telomerase activity in lymphoblastoid (n = 5) and lymphoma cell lines (n = 7), hyperplastic lymph nodes (n = 6) and tonsils (n = 5), and tissues involved by non-Hodgkin's lymphoma (NHL) (n = 43) and Hodgkin's disease (HD) (n = 14). Clearly evident telomerase activity was found in all lymphoblastoid and lymphoma cell lines, and in 34 of 43 cases (80%) of NHL. These results were expected because of the proliferative and immortal nature of the cell lines and most malignant cells. However, positive results were obtained with the TRAP assay in all hyperplastic lymph nodes and tonsils, which raises the issue of derepression of telomerase activity during an immune response. Telomerase activity alone therefore does not distinguish malignant lymphoid proliferations from reactive states. Telomerase activity was detected in only 1 of 14 cases (7%) of lymphoid tissues involved by HD. Eight of the 13 negative cases were considered to be interpretable because of the lack (3 of 13 cases) or low level (5 of 13 cases) of telomerase inhibition. The five remaining cases could not be evaluated because of their telomerase inhibitor content. The findings imply either transient or very low levels of telomerase activity in HD or that HD for the greater part is a telomerase-independent neoplasm. Microdissection studies are needed to identify subsets of cells carrying telomerase activity in both reactive and neoplastic lymphoid tissues.

Oligonucleotide clonospecific probes directed against the junctional sequence of t(14;18): a new tool for the assessment of minimal residual disease in follicular lymphomas

Follicular lymphomas are often associated with t(14;18) chromosomal translocation. The rearrangement site (bcl-2/JH junctional region) between the two chromosomes is hypervariable regarding its size and DNA sequence, and is a potential specific marker for the neoplastic clone of each patient. We report the use of the polymerase chain reaction (PCR) technique for detecting and sequencing clonal bcl-2/JH rearrangements in lymph nodes and/or bone marrow specimens from patients with follicular lymphoma. 53 patients at diagnosis (n = 40) or at relapse (n = 13) were studied. 25 of these 53 cases were found to have the t(14;18) translocation involving either the major breakpoint region (MBR) (n = 21) or the minor cluster region (mcr) (n = 4). Since our PCR technique could detect the translocation in 1/10(6) cells we had to distinguish malignant cells from possible t(14;18)-bearing non-malignant cells which could be present during and after treatment. The bcl-2/JH junctional regions were therefore sequenced in order to synthesize an anti-junction oligonucleotide probe specific for each patient's malignant clone (clonospecific probe). Using these clonospecific probes for hybridization it was possible to detect one malignant cell mixed with 10(6) normal cells. 28 patients with advanced stage (stage III and IV), had been enrolled for treatment with myeloablative chemoradiotherapy and autologous bone marrow transplantation (ABMT). In 12 of these patients bcl-2/MBR translocation was found at diagnosis and used as a marker to detect the presence of residual lymphoma cells in serial bone marrow (BM) and peripheral blood (PB) samples. In three relapsed patients (with available tissue samples at diagnosis and relapse), clonospecific probes clearly demonstrated the same bcl-2/JH junction, thus confirming that the relapse occurred from the same malignant clone, and which remained stable without any clonal evolution of its junctional region throughout the course of the disease. These results demonstrate the value of the t(14;18) clonospecific probes as a diagnostic tool in the detection of minimal residual disease and relapses in patients with follicular lymphoma.

Bcl-x gene expression in Hodgkin's disease

Bcl-x is a Bcl-2-family protein that has been previously detected in cortical thymocytes, plasma cells, and activated lymphocytes. We report here on the high detection rate of the Bcl-x protein found in 86% of Hodgkin's disease samples and on the significance regarding its complex role among the Bcl-2-family of proteins: Bcl-x is known to heterodimerize with Bcl-2 (an anti-apoptosis protein) and with Bax, a potent inducer of cell death. Moreover, recent evidences show that Bcl-x may induce multiple drug resistance in vitro, suggesting that chemical or biological interactions with this protein may have potential therapeutic value in Hodgkin's disease.

Primary mediastinal large B-cell lymphoma. A clinicopathologic study of 141 cases compared with 916 nonmediastinal large B-cell lymphomas, a GELA ("Groupe d'Etude des Lymphomes de l'Adulte") study

Among non-Hodgkin's lymphomas, primary mediastinal large B-cell lymphoma (PMLCL) has been considered a separate entity that has specific clinical and histological aspects and a poor prognosis. In this study, we reexamined the clinicopathologic features and the response to current treatment of 141 PMLCL and compare them with 916 nonmediastinal large B-cell lymphomas (NMLCL) recorded in the same period and treated with similar combined chemotherapy. The clinical features of PMLCL at diagnosis were largely homogeneous and distinct from NMLCL, with a predilection for young women (59% with a mean age of 37 years versus 42% with a mean age of 54 years), bulky tumor (77% versus 7%, p < 10(4)), high serum lactic dehydrogenase (LDH) level 76% versus 51%, p < 10(4)), and frequent intrathoracic extension to adjacent organs such as pleura, pericardium, and lung. By contrast, extrathoracic or hematologic dissemination was uncommon (2% of bone marrow involvement versus 17%). All patients had diffuse large B-cell nonimmunoblastic, nonanaplastic lymphomas. Histological analysis of the 141 PMLCL evaluated two common patterns: the presence of large cells with clear cytoplasm (found in 38% of cases) and the presence of fibrosis (marked in 25% of cases). The presence of clear cells or intense fibrosis did not constitute prognostic indicators. Immunologic and molecular analysis assessed the profile of bcl-2 expression and the presence of Epstein-Barr virus (EBV) in PMLCL: 30% expressed a high level of bcl-2 protein; EBER RNAs were detected by in situ hybridization in only two of the 41 cases tested. Monotypic light chain restriction could be demonstrated in seven of the 41 PMLCL tested on fixed-section. Treated with polychemotherapy regimens without radiotherapy, 79% of PMLCL patients achieved a complete remission compared with 68% in the NMLCL patient group (p = 0.01). Overall, 3-year survival rates were estimated at 66 and 61%, respectively (p = 0.05), and disease-free survival rates were not significantly different (61 versus 64%). Stratified analysis on the International Prognostic Index (based on age, tumor stage, serum LDH level, and performance status) showed no difference in the overall and disease-free survivals between the two lymphoma groups. In conclusion, PMLCL can be combined with other diffuse large B-cell lymphomas on morphologic grounds; it is not associated with EBV. It responds favorably to treatment and should be managed like other high-grade lymphomas of equivalent histology. However, the uncommon clinical presentation makes it a distinct entity.

Immunodetection of apoptosis-regulating proteins in lymphomas from patients with and without human immunodeficiency virus infection

The expression of the apoptosis-regulating genes Bcl-2, Bcl-x, Bax, Mcl-1, and p53 analyzed in 4 cases of human immunodeficiency virus (HIV)-associated Hodgkin's disease, in 36 cases of HIV-related non-Hodgkin's lymphomas (NHLs), and in 109 cases of non-HIV-related NHLs by using immunohistochemistry. HIV-associated Hodgkin's disease samples were positive for all markers. For the HIV-related NHL samples, 36, 66, 88, 100, and 94% of the cases were Bcl-2, Bcl-x, Bax, Mcl-1, and p53 were found to be expressed in 69, 65, 82, 83, and 42%, respectively. No significant differences were observed in Bax and Mcl-1 staining between HIV-unrelated NHLs of B cell and T cell types. In contrast, Bcl-2 was positive in 66/79 (83%) and 10/30 (33%) of B cell and T cell HIV-unrelated NHLs, respectively (P2 < 0.001). Peculiar patterns were observed for hairy cell leukemia (Bax+, Bcl-2+, Mcl-1-) and for anaplastic large cell lymphoma (Bax+, Mcl-1+, Bcl-2-) in HIV-unrelated NHLs. Of interest, all cases with a positive expression of Bax were also found to express either Mcl-1 and/or Bcl-2, suggesting that Mcl-1 and Bcl-2 may counteract the pro-apoptosis function of Bax in vivo by protein-protein interaction within the tumor cell, as demonstrated previously in vitro. These results suggest that apoptosis regulation may have a role in the pathogenesis of some HIV-related and HIV-unrelated NHLs.

Expression of the cell death-inducing gene bax in carcinomas developed from the follicular cells of the thyroid gland

The expression of apoptosis-regulating proteins, Bcl-2, Bax, Mcl-1, and Bcl-X, was evaluated by immunohistochemical methods in 39 cases of thyroid carcinomas. Normal thyroid tissues showed a consistent expression of Bcl-2 and Mcl-1 whereas Bax and Bcl-X proteins were essentially absent from most follicular thyroid cells. Bax expression was observed in all papillary carcinomas (n = 23) and in 8 of 10 follicular carcinomas. The intensity of Bcl-2 immunostaining was generally higher in follicular tumors (n = 10) than in papillary carcinomas (n = 21 of 23). However, in undifferentiated tumors, both Bax and Bcl-2 were weakly expressed. Mcl-1 protein expression was similar to that of Bax in papillary and follicular tumors, but was also frequently detectable in undifferentiated tumors. Bcl-X immunostaining was seen in all undifferentiated tumors (n = 6), in 22 of 23 papillary tumors, and in 5 of 10 follicular tumors. Our findings show that the regulation of bcl-2 family gene expression is different in normal thyroid tissue compared to that of its neoplastic counterpart and varies with the tumor subtype. In particular, unlike normal thyroid epithelium, the apoptosis-blocking gene bcl-X and the apoptosis-inducing gene bax are frequently expressed in thyroid carcinomas derived from the follicular cells. Thus, alterations in the expression of these bcl-2 family genes may contribute to the pathogenesis of thyroid carcinomas.

Hodgkin's disease following mycosis fungoides: phenotypic and molecular evidence for different tumour cell clones

AIMS

(1) To assess the clonality of tumour cells in two patients with mycosis fungoides who subsequently developed Hodgkin's disease; and (2) to determine whether there is a clonal relation between these two disorders.

METHODS

Cutaneous tissue samples involved by mycosis fungoides and lymph nodes involved by Hodgkin's disease from both patients were investigated by immunohistochemistry and the polymerase chain reaction.

RESULTS

Mycosis fungoides tumour cells in both patients expressed multiple T cell associated antigens; Reed-Sternberg (RS) cells had the null phenotype. T cell receptor gamma chain genes were clonally rearranged in mycosis fungoides cells but not in RS cells, including variants, in both patients. In the patient with intermediate transformation to large cell lymphoma, immunoglobulin heavy chain genes were rearranged in the cutaneous tumour, but not in the lymph node involved by Hodgkin's disease.

CONCLUSION

The divergent antigen expression and gene rearrangements observed in these two patients strongly suggest that Hodgkin's disease and mycosis fungoides are not derived from a single tumour cell clone.

Frequent expression of the cell death-inducing gene Bax in Reed-Sternberg cells of Hodgkin's disease

The expression of a cell death-inducing gene, Bax, was investigated in 52 cases of Hodgkin's disease in parallel with Epstein-Barr virus and was compared with the immunodetection of other apoptosis-regulating proteins, Mcl-1, Bcl-2, and Bcl-x. Bax immunostaining was found in 92% of the cases, among them 28% with a strong signal in more than 75% of the Reed-Sternberg cells. Mcl-1 was positive in 80% of the cases, whereas Bcl-2 and Bcl-x were found in 53% and 88% of the cases, respectively. Of 48 (89%) Bax-positive tumors, 43 were found to express apoptosis-inhibiting proteins such as Mcl-1 or Bcl-2. With the exception of 1 case, all Bax-positive tumors also expressed either Bcl-2, Bcl-x, Mcl-1, or combinations of these anti-apoptotic proteins. No correlation was found between Bax expression and the presence of apoptotic cells as detected by morphology and the in situ 3' OH-DNA end-labeling technique. Our findings show that the apoptosis-inducing gene Bax expression is frequently expressed in Hodgkin's disease, providing a potential explanation for the good chemoresponses generally obtained for patients with this neoplastic disorder.

Characterization of Epstein-Barr virus-infected cells in benign lymphadenopathy of patients seropositive for human immunodeficiency virus

The authors investigated 25 benign lymph nodes in patients infected with the human immunodeficiency virus (HIV) by in situ hybridization (ISH) and immunohistochemistry (IHC) to detect and characterize the Epstein-Barr virus (EBV)-infected cells. After ISH, 22 lymph nodes were found to contain various numbers of Epstein-Barr-encoded RNA (EBER)-positive cells. Most of these cells were B cells. In six lymph nodes with numerous EBV-infected cells, EBNA2-positive/LMP1-positive lymphoblastoid cells were detected by IHC. Exceptional cells (in two specimens) were positively labeled with antigen-Z Epstein-Barr replicative activator (ZEBRA) antibody or BamHI Left Frame 1/Not I (BHLF1/Not I) probes, indicating that EBV replication is not enhanced in the lymphocytes. In normal conditions (healthy individuals), small lymphocytes that express a restricted pattern of viral genes do escape immune response, whereas lymphoblastoid cells do not. Thus, impaired immune system may account for the late proliferation of lymphoblastoid cells (Epstein-Barr nuclear antigen [EBNA]2positive/latent membrane protein [LMP]1 positive) in HIV-infected patients, and could explain why EBV-driven, acquired immunodeficiency syndrome (AIDS)-related, non-Hodgkin's lymphoma occur more frequently in patients with low CD4-positive T cells.

Predominant expression of the long isoform of Bcl-x (Bcl-xL) in human lymphomas

Bcl-x is a member of the bcl-2 family of proteins which are characterized by their ability to modulate apoptosis. Alternative splicing results in two distinct bcl-x mRNAs encoding a long isoform, bcl-xL, which acts as a bcl-2 agonist; and a short isoform, bcl-xS, which inhibits bcl-2 effects. The aim of the study was to determine whether bcl-x is expressed in lymphoma tissues and to characterize the respective production of bcl-xs and bcl-xL. We investigated the expression of bcl-x mRNA in a series of 50 non-Hodgkin's lymphomas (NHL) and Hodgkin's disease (HD) cases using a RT-PCR method in order to amplify both transcripts simultaneously, and to estimate their relative abundance. The rearrangements of the bcl-2 gene were analysed by RT-PCR expression of the hybrid bcl-2-lgH mRNA. In addition, 20 PCR-positive NHL cases and three HD cases were analysed by immunohistochemistry using bcl-x polyclonal antisera. RT-PCR showed bcl-x expression in 43/45 NHLs and 5/5 HD cases. The bcl-xL transcript was predominant in all positive cases and was associated with variable amounts of bcl-xS. There was no significant correlation between the profile of bcl-xL/bcl-xS expression and the histological and immunological subtyping. Bcl-x immunodetection was positive in the neoplastic cell component in all analysed cases, but the degree of staining was highly variable between cases. Expression of the hybrid bcl-2-IgH gene was detected by RT-PCR in five cases of follicular NHL and in one case of HD, but this group of tumours did not display a particular profile of bcl-xL/bcl-xS expression. We conclude that bcl-x is commonly expressed by malignant cells in various types of malignant lymphomas, with a predominance of the bcl-xL transcript. Since the corresponding bcl-xL isoform can block the cell death machinery and potentialize bcl-2 effects, it may be involved in some pathways of lymphomagenesis.

Deletion variants within the NF-kappa B activation domain of the LMP1 oncogene prevail in acquired immunodeficiency syndrome-related large cell lymphomas and human immunodeficiency virus-negative atypical lymphoproliferations

This sequencing study of 17 acquired immunodeficiency syndrome-related lymphomas (9 primary brain, 8 systemic) and 8 human immunodeficiency virus-negative atypical lymphoproliferations expressing large amounts of the latent membrane protein 1 (LMP1) of Epstein-Barr virus was performed to characterize the carboxy terminal NF-kappa B activation domain of LMP1 at the molecular level in an immunocompromised host. In-frame deletions within the NF-kappa B activation domain were identified in all but 2 primary brain lymphomas, 4 systemic lymphomas, and 4 atypical lymphoproliferations, ie, in 60% of cases. In addition, non silent point mutations (range 1 to 5, mean 3.3) were detected in all cases. Although all changes occurred within the first 100 nucleotides of the carboxy terminal NF-kappa B activation domain--a critical sequence for the protein half-life--not a single point mutation was found in the remaining 62 nucleotides, necessary for malignant transformation. Such a clustering of nonrandom sequence variations, associated with a high oncoprotein expression in immunocompromised hosts, suggests that this part of the LMP1 oncogene behaves as a hypervariable region with natural selection of growth-promoting variants through prolongation of the protein half-life.

Vincristine degradation by serum from leukemic patients: role of myeloperoxidase

Myeloperoxidase (MPO) has been shown to catalyze the in vitro degradation of vincristine (VCR). Given that MPO is a lysosomal enzyme that can be released into the circulation by both normal activated and leukemic myeloid cells, we investigated the possibility that sera from patients with acute myeloblastic leukemia (AML) might exhibit an increased capacity to degrade VCR. 31 serum samples (23 from patients with acute myeloblastic leukemia and 8 from patients with other conditions) were analyzed after incubation with ((3)H)VCR by using HPLC. Sera from patients with AML demonstrated an increased ability to breakdown VCR when compared to either normal sera or to sera from patients with lymphoid leukemias. VCR degradation was significantly increased by adding hydrogen peroxide, an electron donor for MPO, to the sera and was almost completely inhibited by adding 1 mM acetaminophen, an inhibitor of MPO. VCR peroxidation in the presence of hydrogen peroxide correlated both with the number of leukemic blasts in the circulation at the time the sera were obtained and with serum MPO concentrations determined by an immunoassay. These data suggest that the inactivity of VCR in AML may be due in part to its rapid peroxidation to inactive species by the MPO of leukemic myeloblasts.

High incidence of the t(2;5)(p23;q35) translocation in anaplastic large cell lymphoma and its lack of detection in Hodgkin's disease. Comparison of cytogenetic analysis, reverse transcriptase-polymerase chain reaction, and P-80 immunostaining

Fifty-six cases of anaplastic large cell lymphoma (ALCL), 23 cases of Hodgkin's disease, and 16 cases of diffuse large cell lymphoma were investigated for the t(2;5)(p23;q35) translocation. The translocation was detected by using cytogenetic analysis, reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry with P80 antibody directed against the kinase domain of anaplastic lymphoma kinase (ALK) of the chimeric NPM/ALK protein. In all but three cases of ALCL, we found an agreement between cytogenetic analysis, RT-PCR, and P80 staining. However, in one case, the t(2;5) translocation was detected with cytogenetic analysis, but RT-PCR and P80 staining were found to be negative. Conversely, in another case the karyotype was normal, but the hybrid mRNA and P80 staining were found to be positive. In one case, malignant cells showed a translocation involving chromosomes 1q25 and 2p23 and were strongly positive for P80 staining. Such a result could be expected because P80 antibody detects the kinase domaine of the ALK protein encoded by chromosome 2p23. Overall 73.2% (41 of 56) of cases were found to be positive. However, the highest percentage (23 of 26 cases; 88.5%) of P80 positive cases was found in children compared with 60% (18 of 30 cases) in adult ALCL (P < .05). In Hodgkin's disease, Reed-Sternberg cells were found to be clearly negative by RT-PCR and with P80 antibody. The latter results suggest that Hodgkin's disease and t(2;5)-positive ALCL are distinct biological entities and that the demonstration of the t(2;5) translocation is of diagnostic importance in differentiating these two entities. The results of the present study indicate that immunohistochemistry with P80 antibody is a reliable method for detecting NPM/ALK chimeric protein.

Chemotherapy combined with zidovudine and GM-CSF in human immunodeficiency virus-related non-Hodgkin's lymphoma

OBJECTIVE

The treatment of patients with non-Hodgkin's lymphoma related to the human immunodeficiency virus (HIV-NHL) is complicated by the underlying acquired immunodeficiency syndrome (AIDS). Patients without adverse prognostic factors (no AIDS prior to lymphoma, CD4+ lymphocyte counts greater than 100 x 10(6)/l and good performance status) can be cured of lymphoma and experience long-term survival. Our previous study with the intensive chemotherapy LNH84 regimen yielded a 63% complete response (CR) rate but median survival was only nine months, half of the patients died of AIDS and the other half of their lymphoma. We report here the results of a phase II study combining the same chemotherapy with zidovudine and GM-CSF. Our goal was to improve the treatment outcome over that of our previous study; GM-CSF was expected to decrease the hematological toxicity of chemotherapy and thus permit a dose intensity increase, while zidovudine was supposed to slow down the evolution of AIDS.

DESIGN AND SETTING

A phase II non-randomized prospective clinical trial in 7 centres.

PATIENTS AND METHODS

Thirty-two consecutive adult patients presenting HIV-NHL and performance status of less than three without active opportunistic infection underwent three cycles of doxorubicin 75 mg/m2, cyclophosphamide 1,200 mg/m2, vindesine 2 mg/m2 for two days, bleomycin 10 mg for two days and prednisolone 60 mg/m2 for five days (ACVB). Chemotherapy was associated with zidovudine (5 mg/kg/d) and GM-CSF (5 mu g/kg/d). The induction phase was followed by a four-month consolidation phase.

RESULTS

CR and PR > 75% were observed in 56% of patients; 25% of the patients died during the induction phase. These results were analogous to those of the previous study (63% and 14%, respectively). Neither hematological tolerance nor dose intensity were improved. With a mean follow-up of 23.5 months, median survival was 6.7 months. The rate of non-NHL AIDS-related death during CR was not reduced (22% in our study vs. 16% in our previous one).

CONCLUSIONS

GM-CSF failed to reduce significantly the cumulative hematological toxicity of chemotherapy and zidovudine. New antiviral agents without hematological toxicity would perhaps be useful in this setting.

High expression of the bcl-x gene in Reed-Sternberg cells of Hodgkin's disease

The expression of bcl-x protein, a bcl-2-related protein present in cortical thymocytes, activated lymphocytes, and plasma cells of reactive lymph nodes, was investigated in 44 cases of Hodgkin's disease (HD) in parallel with bcl-2 and Epstein-Barr virus (EBV) status. Eighty-six percent of the cases were positive for bcl-x, among them 27% with a strong signal in more than 75% of the Reed-Sternberg cells. Positivity for bcl-x was found in, respectively, 100% and 92% of the nodular sclerosis and mixed cellularity subtypes, although 4 cases of lymphocyte predominance subtype were negative. This finding was in contrast with the weaker positivity for bcl-2 staining in 44% of the cases. EBV small RNAs were detected in 43% of the cases by using in situ hybridization. Of interest, 100% of the EBV-positive samples were positive for bcl-x, whereas only 38% of these cases were bcl-2 positive. Our findings show that the bcl-x gene expression is high in HD, suggesting that bcl-x may have a role in the pathogenesis of at least some cases of HD via apoptosis regulation.

Bone marrow involvement in anaplastic large cell lymphoma. Immunohistochemical detection of minimal disease and its prognostic significance

Bone marrow involvement by anaplastic large cell anaplastic large cell (ALC) lymphoma can be difficult to detect on routine morphologic examination alone. In a series of 42 patients with ALC lymphoma, the authors analyzed: (1) the usefulness of a limited panel of monoclonal antibodies directed against CD30 (Ber-H2, HRS4) and epithelial marrow involvement on routinely processed biopsy specimens; and (2) the prognostic significance of bone marrow involvement as detected on both morphologic and immunohistochemical grounds. On conventional examination, 17% of the patients were found to have bone marrow involvement at diagnosis. However, after immunohistochemical analysis, occult malignant cells were detected in 23% of the patients with negative bone marrow biopsy on routine histology. The low percentage of positive cases on routine morphologic examination compared to immunohistochemical examination was related to: (1) the scarcity of neoplastic cells which were scattered among hematopoietic cells; (2) the difficulty of distinguishing malignant cells from immature hematopoietic elements; and (3) the absence of alteration of the reticulin network. The authors observed a significant association between marrow infiltration and the presence of hematologic abnormalities (mostly anemia or cytopenias) at diagnosis, both in children and adult patients. More importantly, a significant lower survival was seen in patients with bone marrow involvement compared to those without bone marrow involvement. Immunohistochemistry with anti-CD30 and anti-EMA antibodies should be performed systematically in bone marrow biopsies from patients with ALC lymphoma to reliably identify the presence of bone marrow involvement that appears to carry a poor prognosis.

Epstein-Barr virus in familial Hodgkin's disease

Hodgkin's disease (HD) has been found to be linked to Epstein-Barr virus (EBV). Familial HD (FHD) may be related to a possible unknown agent. We have determined whether EBV small RNAs (EBERs) were found in Reed-Sternberg cells from FHD. Five families were studied for histological subtype and EBER presence. There was a striking similarity in FHD subtypes of each family and 3/11 (27%) of the cases were EBER positive. In conclusion, EBV EBERs are only infrequently found in FHD and other factors including viruses different from EBV should be further investigated in FHD.

Persistence of the same viral strain in early and late relapses of Epstein-Barr virus-associated Hodgkin's disease

Twelve cases of relapsing Hodgkin's disease were investigated for the presence of Epstein-Barr virus (EBV). Of these, 7 cases contained EBV gene products (LMP1, EBER RNA) in the diagnostic Reed-Sternberg cells and variants at first presentation and at relapse(s), whereas 5 cases were negative at both first diagnosis and relapse. Among the 7 EBV-positive cases, material for DNA extraction was available in 2 cases at both diagnosis and relapse(s). Ig and T-cell receptor gene rearrangements displayed a germline configuration in the 2 cases. However, Southern blot analysis of the terminal repeats (TR) of EBV genome showed that, in 1 of the 2 cases, the fragment was of the same size at diagnosis and in the subsequent two relapses (1 early and 1 late). The second case contained monoclonal EBV genome at diagnosis, but the Southern analysis of the TR was negative at relapse. The latent membrane protein (LMP1) sequence analysis confirmed the persistence of a distinctive viral strain in each of the 2 cases with individual abnormalities within the carboxy terminal region (5 point mutations and a 30-bp deletion for the first case and 6 point mutations for the second case). The persistence of a given strain in early and late relapses is evidence towards the view that in Hodgkin's disease such relapses are related to a single residual tumor cell clone.

bcl-2 proto-oncogene and Epstein-Barr virus latent membrane protein-1 expression in AIDS-related lymphoma

The expression of bcl-2 protein and Epstein-Barr virus (EBV) latent membrane protein 1 (LMP-1) was investigated in 18 cases of lymphoma occurring in the acquired immunodeficiency syndrome (AIDS). EBV small RNAs were detectable in tumour cells in all cases by in situ hybridization with EBER oligonucleotides. LMP-1 expression was detected in 61% of the cases, and 55% were positive for bcl-2. Dual expression of LMP-1 and bcl-2 was found in 8/18 (44%) cases, while five cases (28%) expressed either LMP-1 or bcl-2 and five expressed neither. Thus, there was an inconsistent relationship between the presence of EBV and the expression of bcl-2. One LMP-1 negative case was found to express bcl-2 in reactive lymphocytes but not in lymphoma cells. No clinical features were found to correlate statistically with LMP-1 or bcl-2 expression in the tumour cells. However, CD4 counts at diagnosis were significantly lower in bcl-2 positive cases (P < 0.05). The respective roles of EBV LMP-1 and the expression of bcl-2 in lymphogenesis in AIDS patients remains complex and is not yet fully understood.

Epstein-Barr virus (EBV) replicative gene expression in tumour cells of AIDS-related non-Hodgkin's lymphoma in relation to CD4 cell number and antibody titres to EBV

OBJECTIVE

To determine whether activation of Epstein-Barr virus (EBV) replication in tumour cells of AIDS-related non-Hodgkin's lymphoma (ARNHL) is correlated with CD4+ cell counts and influences antibody response to EBV [anti-Z Epstein-Barr replicative activator (ZEBRA), anti-early antigen (EA), anti-viral capsid antigen (VCA)].

DESIGN

Retrospective study based on immunohistochemistry and in situ hybridization to detect EBV replicative gene products in tissue samples from patients affected by ARNHL and correlation with CD4+ cell counts and results of EBV serology (including anti-ZEBRA activity) in sera from the same patients.

METHODS

Seventeen out of 22 cases of ARNHL were selected for the presence of EBV [Epstein-Barr early region (EBER) RNA-positive]. Immunohistochemistry was performed with anti-ZEBRA, anti-EA-restricted, anti-VCA antibodies and in situ hybridization with BHLF1/NotI oligoprobes on tumour samples. Results were statistically correlated with those of CD4+ cell counts (17 out of 17) and with anti-EBV antibody titres (13 out of 17) assessed using standard immunofluorescence method and enzyme-linked immunosorbent assay procedure using recombinant ZEBRA protein and synthetic peptides as antigens.

RESULTS

BZLF1 (ZEBRA) or early gene products (EA-R and EA-D/BHLF1/NotI) were detected in a small proportion (< 0.01-5%) of tumour cells in eight of these 17 cases by immunohistochemistry and in situ hybridization. Demonstration of replicative gene expression did not correlate with either low CD4+ cell counts (P > 0.05) or anti-EBV antibody titres (P > 0.05). Anti-ZEBRA activity was not significantly increased in patients affected with ARNHL, the cells of which expressed replicative gene products (P > 0.05).

CONCLUSION

The degree of immunodeficiency does not clearly enhance replicative gene expression in tumour cells of ARNHL. EBV serology, including anti-ZEBRA activity, is not a reliable tool for predicting the occurrence of such proliferations.

B-cell lymphoma following polycythemia vera: evidence for the involvement of two different clones

We report here two patients with polycythemia vera (PV) who developed secondary non-Hodgkin's lymphoma (NHL). Both cases were high grade B-cell NHL. Cytogenetic analysis of bone marrow and lymph node was performed in each case and showed numerous chromosomal abnormalities. Of interest, chromosomal abnormalities of the PV and of the NHL clones were different, suggesting the possible involvement of two different clones. A 11q23 breakpoint was common between the two cases and the putative role of this breakpoint in the pathogenesis of the NHLs is discussed.

Potential strategies for circumventing myeloperoxidase-catalyzed degradation of vinca alkaloids

Myeloperoxidase (MPO) has recently been shown in an in vitro, cell-free system to catalyze the peroxidative degradation of vincristine (VCR). Oxidation of VCR involves a ring fission between positions 20' and 21', and is thought to be facilitated by the presence of an hydroxyl (-OH) group at position 20'. We report here two different approaches, both with potential clinical application, to decrease MPO-catalyzed vinca degradation. Firstly, we tested the hypothesis that -OH substitution at position 20' increases vinca susceptibility to peroxidation by comparing the relative extent of degradation of vinorelbine (Navelbine or NVB), which lacks a 20' hydroxyl substitution, with that of VCR. As anticipated, NVB was significantly less susceptible to MPO-catalyzed peroxidation than was VCR (p < 0.01). Secondly, we screened an array of compounds that are in current clinical use for their ability to inhibit MPO. Acetaminophen, N-acetylcysteine, propylthiouracil, D-penicillamine, mefenamic acid, dapsone, and methimazole all inhibited MPO at clinically achievable concentrations. Insofar as increased MPO activity has been observed in patients with acute myeloid leukemia, these findings suggest potential strategies for improving the activity of vinca alkaloids in this disease.

Antisense inhibition of myeloperoxidase increases the sensitivity of the HL-60 cell line to vincristine

Myeloperoxidase (MPO), a heme-peroxidase found in the HL-60 myeloblastic cell line, is involved in vincristine (VCR) metabolism and the inactivation of this drug. We have examined whether decreased MPO activity correlated with increased sensitivity to VCR toxicity in myeloid leukemia cells. We have used MPO antisense RNA to reduce 60% of the MPO activity in the HL-60 cells. The MPO-deficient HL-60 cell line, C15, was significantly more sensitive to VCR than the parental MPO-positive cell line. Both cell lines were negative for P170-glycoprotein expression. Conversely, an MPO-positive C15 subclone was more resistant to VCR than the MPO-deficient C15 cell line. No significant differences in cytotoxic effects were observed between MPO-positive and MPO-deficient cells, following treatment with either daunorubicin or actinomycin D, two multidrug resistance-related drugs. These results strongly support an important role for MPO in VCR resistance in HL-60 cells. Antisense manipulation of the MPO content of myeloid cells could be of potential interest in leukemia treatment.

Escalating dose of mitoxantrone with high-dose cyclophosphamide, carmustine, and etoposide in patients with refractory lymphoma undergoing autologous bone marrow transplantation

PURPOSE

We conducted a dose-finding study of mitoxantrone (MITO) in combination with high-dose cyclophosphamide, carmustine (BCNU), and etoposide (CBV) in refractory lymphoma undergoing autologous bone marrow transplantation (ABMT). The objective were to determine the following: (1) the maximum-tolerated dose of MITO, (2) the extramedullary toxicity of this regimen, (3) its antitumor activity, and (4) the pharmacokinetic characteristics of MITO at each dose level.

PATIENTS AND METHODS

Escalating doses of MITO (15 to 90 mg/m2, single bolus infusion on day -8) followed by CBV were administered to 20 patients (mean age, 38.5 years) with refractory lymphoma. MITO concentrations were determined by high-performance liquid chromatography (HPLC).

RESULTS

No toxic death occurred. The maximum-tolerated dose appears to be 75 mg/m2. Two of five patients treated with 90 mg/m2 developed severe organ toxicity, versus zero of 15 treated with doses up to 75 mg/m2. Duration of neutropenia was longer for patients treated with 90 mg/m2 (31.7 days) than for patients treated with doses up to 75 mg/m2 (22.1 days) (P < .05). A linear relationship was observed between administered dose of MITO and (1) plasma peak value, (2) area under the curve (AUC), and (3) plasma concentration on the day of marrow infusion (day 0). Hematologic toxicity was related to the terminal half-life (T1/2) of MITO, and day-0 plasma concentration. A high complete response (CR) rate was observed (60%), and eight of 11 (73%) patients treated with MITO > or = 60 mg/m2 achieved a CR.

CONCLUSION

MITO (up to 75 mg/m2) and CBV can be administered with acceptable toxicity and a promising CR rate in this poor-risk population, justifying further phase II studies.

Plasma and cellular pharmacokinetics of mitoxantrone in high-dose chemotherapeutic regimen for refractory lymphomas

We have studied the plasma and peripheral leukocyte pharmacokinetics of mitoxantrone associated, in a high-dose regimen, with cyclophosphamide, carmustine, and etoposide in patients with refractory lymphoma undergoing autologous bone marrow transplantation. Nineteen patients with refractory lymphoma were involved in a clinical trial with escalated doses (15-90 mg/m2) of mitoxantrone administered by 30-min i.v. infusion 8 days before an autologous bone marrow transfusion. Mitoxantrone was measured by high-performance liquid chromatography in plasma and peripheral lymphocytes. The plasma pharmacokinetics of mitoxantrone was linear between 15 and 90 mg/m2: total body clearance (19.3 +/- 6.2 liter/h/m2) and volume of distribution at steady state (486 +/- 254 liter/m2) were not altered by increasing the dose. The exposure of bone marrow transplant to the plasma residual concentration of mitoxantrone was correlated with the limiting hematological toxicity of the regimen (P < 0.001). At all times, the mitoxantrone concentration in peripheral cells was much higher than in plasma and was retained at a constantly high concentration level. Whereas cellular versus plasma maximum concentration ratio was near 1, the area under the concentration +/- time curve ratio reached 100, suggesting a long elimination half-life from cells. Plasma and cellular pharmacokinetics data of mitoxantrone reinforce the idea that this drug is a good candidate for high-dose chemotherapy regimen.

[Histogenesis of malignant lymphomas]

The strides achieved by immunohistochemical techniques, the development of monoclonal antibodies and, more recently, molecular biology have brought deep changes in the concept of histogenesis and in the classification of malignant lymphomas. After blockage, each of the cells which mark out the transformation of B and T may give birth to a malignant lymphoma. In most cases lymphoproliferations retain the immunological (differentiation markers) and morphological attributes of the normal cells from which they derive. It is on this corpus of data that the present histogenesis and classifications are resting. However, the complexity of lymphoma histogenesis is related to heterogeneous lymphoid populations which are not a mere division into B and T cells. There are numerous and not yet clearly individualized subpopulations the morphological and antigenic features of which are imperfectly known. On the other hand, the development of in situ hybridization techniques and of molecular biology (PCR) has provided useful data on the aetiology of malignant lymphomas. The latest results obtained suggest that several viruses (Epstein-Barr, HTLV-1, HHV-6) might play a predominant oncogenic role.

Prevention of regimen-related toxicities after bone marrow transplantation by pentoxifylline: a prospective, randomized trial

Elevated levels of tumor necrosis factor alpha (TNF-alpha) have been reported to correlate with the development of transplant-related complications after bone marrow transplantation (BMT). In a recent phase I-II trial, oral administration of pentoxifylline (PTX), a xanthine derivative capable of downregulating TNF-alpha production in vitro, was reported to reduce morbidity and mortality in patients undergoing BMT. We conducted a prospective randomized trial of PTX therapy among 140 patients undergoing either allogeneic (n = 51) or autologous BMT (n = 89). Patients were randomized to receive (n = 70) or not receive (n = 70) oral PTX, 1,600 mg/d in four divided doses from day -8 until day + 100 post-BMT. The incidence of mucositis requiring morphine sulfate (MSO4) was similar in both groups (42.9%), with the mean number of days with MSO4 being 7.8 (SD = 3.4) in the PTX group versus 8.2 (SD = 3.4) in the control group (NS). The incidence of renal insufficiency was not affected by PTX administration (15.7% in the PTX group v 21.4% in the control group [NS]) and the highest serum creatinine value during the first 100 days post-BMT was 119 mumol/L (SD = 82.4) in the PTX group versus 103.9 mumol/L (SD = 57) in the control group (NS). The incidence of grade > or = 2 graft-versus-host disease was similar in each group (11/25 [44%] in the PTX group v 12/26 [46%] in the control group). No significant difference was observed in hematologic toxicity, transfusion requirements, duration of fever, and hepatic toxicity between the treatment groups. In conclusion, our study failed to show a prophylactic effect of PTX in transplant-related toxicities after BMT. On the basis of these findings, we cannot recommend that PTX be part of early mortality and morbidity prevention programs after BMT.

Myeloperoxidase: an enzyme involved in intrinsic vincristine resistance in human myeloblastic leukemia

One of the differences between acute myeloblastic leukemia (AML) and acute lymphoblastic leukemia (ALL) is their sensitivity to vincristine. Although vincristine plays an important role in chemotherapeutic regimens for ALL, it does not possess clinically significant activity in AML. Horseradish peroxidase, a heme-centered peroxidase, oxidatively degrades Vinca derivatives and thereby abrogates their cytotoxic activity. This finding suggested that myeloperoxidase (MPO), a heme-centered peroxidase characteristically found in AML and not in ALL, might also degrade vincristine. We first examined the effects of MPO on vincristine in a cell-free system and demonstrated that this enzyme is capable of catalyzing vincristine's oxidative breakdown. We also observed that vincristine is more rapidly degraded in tissue culture by MPO-positive HL-60 cells than by a MPO-negative HL-60 subclone. The degree of MPO activity in these cell lines correlated in a positive manner with their degree of resistance to vincristine's cytotoxic activity. Moreover, the differential resistance to vincristine observed between these cell lines could be increased by increasing the concentration of H2O2 available to the enzyme. These data support the hypothesis that MPO-mediated oxidation of vincristine accounts in part for this drug's lack of activity in AML.

Intensive combined therapy for previously untreated aggressive myeloma

A trial was initiated to determine the feasibility and efficacy of a three-phase treatment including: (1) induction chemotherapy (IC); (2) high-dose melphalan with total body irradiation supported by unpurged autologous bone marrow transplantation (ABMT); and (3) interferon (IFN) alpha maintenance treatment, in previously untreated aggressive myeloma. Thirty-five consecutive patients, ages under 65 years, were enrolled. Initial induction therapy was randomized between the VAD regimen (vincristine, doxorubicin, dexamethasone) or the VMCP regimen (vincristine, melphalan, cyclophosphamide, prednisone) that were found to give similar results as IC. Thirty-one of 35 (89%) patients, with good performance status and normal renal function after IC, received ABMT. IFN alpha was started soon after ABMT and was well tolerated. Fifteen of 35 (43%) patients achieved complete response (CR) and 14 of 35 (40%) achieved partial response (PR). Low pretreatment beta 2 microglobulin was the only predictive factor for accomplishing CR. The duration of response was significantly affected by the magnitude of response. The 33-month, post-ABMT probability of progression-free survival was 85% for patients in CR versus 24% for patients in PR. The 42-month, post-diagnosis probability of survival was 81%. This overall strategy may represent an advance in the management of multiple myeloma. Furthermore, the high rate and long duration of CR that we observed in patients with low beta 2 microglobulin suggest that such patients may preferentially benefit from this strategy.

Maintenance treatment with recombinant alpha interferon after autologous bone marrow transplantation for aggressive myeloma in first remission after conventional induction chemotherapy

Twenty patients (median age 57 years) with high tumor mass myeloma in first remission after conventional chemotherapy received a two-phase treatment: autologous bone marrow transplantation (ABMT) using a preparative regimen of high dose melphalan plus total body irradiation followed by maintenance treatment with recombinant alpha interferon. Before ABMT all patients were in partial remission, while after ABMT 10 (50%) achieved complete remission, and 10 remained in partial remission (with a 90% decrease in measurable paraprotein in 7/10). With a median follow-up of 19.8 months (12.2-33.5) after diagnosis and 13 months (4-25) after ABMT, the Kaplan-Meier 2-year post-ABMT probability of progression-free survival was 85% (95% CI = 58.7-95.8%). None of the 10 patients in complete remission has relapsed. No toxic death occurred. Alpha interferon was introduced early after ABMT (2.7 months) and was well tolerated. This strategy may represent an advance in the management of aggressive myeloma.

Prevention of gram-positive infections after bone marrow transplantation by systemic vancomycin: a prospective, randomized trial

Gram-positive bacteria are the most commonly isolated organisms after bone marrow transplantation (BMT) and severe streptococcus septicemia has been reported. In order to evaluate the benefit of a gram-positive prophylaxis after BMT, we conducted a prospective, randomized trial of systemic vancomycin among 60 patients undergoing BMT for hematologic malignancies. Patients were randomized to receive (n = 30) or not receive (n = 30) prophylactic vancomycin 15 mg/kg every 12 hours from day -2 until resolution of neutropenia or until the first episode of fever. All patients were treated in laminar air-flow rooms, received sterile diet, total gut decontamination, and had central venous catheters placed surgically. Vancomycin was found to be highly effective in preventing gram-positive infections that occurred in 11 of 30 patients in the control group versus zero of 30 in the vancomycin group (P less than .002). All gram-positive infections occurring in the control group were symptomatic (nine septicemia and two local infections), and one patient with Streptococcus septicemia died with pneumonia. Thus, gram-positive prophylaxis was found to decrease infection morbidity after BMT. Moreover, the number of days with fever (P less than .001), and empiric antibiotic therapy (P less than .01) was reduced without added toxicity or cost. This study confirmed the high prevalence of gram-positive infections after BMT and emphasized the clinical benefits of an adapted prophylaxis.

Detection of Epstein-Barr virus messenger RNA in Reed-Sternberg cells of Hodgkin's disease by in situ hybridization with biotinylated probes on specially processed modified acetone methyl benzoate xylene (ModAMeX) sections

Microscopic intracellular detection of Epstein-Barr virus (EBV) messenger RNA in Reed-Sternberg cells of Hodgkin's disease (HD) was possible by in situ hybridization, in tissue sections prepared by a method termed modified acetone methyl benzoate xylene (ModAMeX). The ModAMeX method was initially developed for simultaneous optimal preservation of leucocyte differentiation antigens and morphology. Two biotinylated DNA probes, corresponding to the same BamHI-W (internal repeat) of the EBV genome were used. EBV mRNA was detected in neoplastic cells in 16 of 54 (30%) lymph node biopsy specimens from usual subtypes of HD (lymphocyte predominance, 0/5; nodular sclerosis, 4/22; mixed cellularity, 12/26; unclassified, 0/1). EBV mRNA was also detected in the lymph node biopsy of 1 additional human immunodeficiency virus (HIV)-related case of HD (mixed cellularity) and in 2 of 4 cases of B-cell lymphomas occurring in patients with acquired immunodeficiency syndrome (AIDS). In other non-Hodgkin's lymphomas, EBV mRNA was detected in only 1 of 41 cases. Cases of HD positive for EBV mRNA were immunostained by CD30 and CD15 antibodies. The hybridization signals were exclusively restricted to Reed-Sternberg cells and variants. When analyzed retrospectively, no statistically significant correlation emerged between hybridization findings, EBV serology, or disease outcome over the 3 years of the availability of ModAMeX technique. The findings support the contention of a direct role of EBV in the pathogenesis of HD, at least in some cases.

Immunohistochemical detection of multidrug resistance associated P-glycoprotein in tumour and stromal cells of human cancers

The distribution of Gp 170, a multidrug resistance (MDR) associated glycoprotein, also called P-glycoprotein (P-gp), was examined by immunohistochemistry, using C219 and MRK16 monoclonal antibodies. Sixty-five tumour tissues were studied which included 40 non-lymphoid tumours, 15 chemoresistant non-Hodgkin's lymphomas and 10 Hodgkin's disease. The study was performed on both cryostat and special fixation processed and paraplast embedded (ModAMeX) sections. The latter method preserves fixation-sensitive antigens such as P-gp and allows a more precise morphological identification of neoplastic and non-neoplastic cell populations in contrast to cryostat sections. Immunohistochemical expression of P-gp was expected and confirmed in many non-lymphoid tumours, but stromal macrophages and endothelial cells were also frequently stained in these cases. In non-Hodgkin's lymphomas, cells that were stained with both C219 and MRK16 monoclonal antibodies on cryostat sections were identified as macrophages and endothelial cells and not neoplastic lymphoid cells, by the ModAMeX technique. These findings suggest that the quantitative assessment of MDR RNA by Northern blotting performed on fresh homogenates overestimates the MDR content of neoplastic cells in a number of lymphoid and non-lymphoid tumours. In addition, the mechanism of chemoresistance in non-Hodgkin's lymphomas is less likely to be associated with P-gp expression.