Human immunodeficiency virus-associated Hodgkin's disease contains latent, not replicative, Epstein-Barr virus

Severe immunodeficiency is associated with reactivation of latent Epstein-Barr virus (EBV) that is manifested by virus replication. It is unknown whether EBV replication also occurs in the Hodgkin's disease (HD) tissue of patients infected with the human immunodeficiency virus (HIV). Therefore, we studied paraffin-embedded lymph nodes from 13 cases of HIV-associated HD to determine the latent or replicative state of EBV infection. All patients were seropositive HIV-infected men; additional clinical information was available for 12 patients. The risk factor(s) for HIV infection were homosexuality (n = 7), intravenous drug abuse (n = 2), homosexuality and intravenous drug abuse (n = 1), sexual promiscuity (n = 1), or hemophilia (n = 1). Advanced clinical stage and B symptoms were common at the time of initial diagnosis of HD. The histological subtype of Hodgkin's disease was universally mixed cellularity, except for a single case classified as nodular sclerosis. Seven cases exhibited foci of relative lymphoid depletion. Five cases contained foci of necrosis. Reed-Sternberg (RS) cells and RS cell variants were positive for CD30/BerH2 and negative for CD45/LCA, CD45RO/UCHL1, and CD20/L26 in all cases. Tumor cells were positive for CD15/LeuM1 in seven cases. In all 13 cases, RS cells and RS cell variants were infected by latent EBV as shown by in situ hybridization to EBV-encoded ribonucleic acid (EBER1). In 12 of 13 cases neoplastic cells coexpressed EBV latent membrane protein 1 (LMP1). EBV replication was examined by two different methods: immunohistochemistry to identify EBV-encoded BZLF1 protein and in situ hybridization to detect EBV BHLF1 transcripts. No positivity in RS or RS cell variants was detected with either assay of EBV replication (95% confidence interval [CI] = 0% to 23%). The findings confirm that EBV is detected more frequently in HIV-associated HD when compared with immunocompetent patients with HD. The findings also suggest that EBV is tightly latent within RS and RS cell variants of HIV-associated HD. It appears that factors other than host immune status are important in maintaining EBV latency in HIV-associated HD.

Lymphomas of the oral soft tissues are not preferentially associated with latent or replicative Epstein-Barr virus

OBJECTIVES

Epstein-Barr virus is periodically shed in the saliva of persons infected by the virus. Epstein-Barr virus has been implicated in the pathogenesis of certain subtypes of lymphoma, particularly high-grade lymphomas. Because high-grade subtypes represent the majority of lymphomas that arise in oral soft tissues, we hypothesized that Epstein-Barr virus might be preferentially associated with oral lymphomas.

STUDY DESIGN

A series of 34 oral lymphomas were diagnosed according to the revised European-American classification scheme. They were examined for the presence of latent Epstein-Barr virus by EBER1 in situ hybridization and for expression of the Epstein-Barr virus replicative protein, BZLF1, by immunohistochemistry.

RESULTS

Epstein-Barr virus EBER1 transcripts were detected in 11 of 31 oral lymphomas including 7 of 10 AIDS-related lymphomas and only 4 of 21 lymphomas that occurred in nonimmunocompromised persons. The Epstein-Barr virus-containing lymphomas were all high-grade histologic subtypes, that is, diffuse large cell, immunoblastic, or Burkitt's lymphomas. In contrast, Epstein-Barr virus was not detected in any of five low-grade oral lymphomas. In the single case of T-cell lymphoma in this study, EBER1 was expressed in the tumor cells. A switch from viral latency to replication, as measured by EBV BZLF1 expression, was identified in rare lymphoma cells in only four cases. This rate of viral replication was not higher than what has been reported in lymphomas arising at other anatomic sites. Although one of our lymphomas arose at a site of previous oral hairy leukoplakia, there was no other evidence that Epstein-Barr virus replication predisposed to development or persistence of oral lymphomas.

CONCLUSIONS

These data suggest that even though Epstein-Barr virus is frequently found in oral secretions, neither latent nor replicative Epstein-Barr virus is present more commonly in oral lymphomas than in lymphomas arising in other anatomic sites, when controlling for immunodeficiency status.

Angiofollicular lymph node hyperplasia (Castleman's disease)

This review provides a comprehensive assessment of angiofollicular lymph node hyperplasia (ALNH) or Castleman's disease including pathogenesis, clinical presentation, histomorphologic and immunophenotypic findings, laboratory results, treatment, and prognosis. A division of ALNH into clinically relevant subtypes provides a framework for the consideration of the disorder. A comprehensive search of the medical literature involving ALNH using Medline was performed. Reports judged to be significant for the understanding of the disorder were analyzed and their findings incorporated into this review. ALNH is divided into localized/unicentric ALNH and generalized/multicentric ALNH due to the profound clinical differences seen between these variants. Localized/unicentric ALNH is separated by clinical and histomorphologic criteria into hyaline-vascular (HV) and plasma-cell (PC) subtypes. Generalized/multicentric ALNH may be divided by clinical criteria into generalized/multicentric ALNH without neuropathy (non-neuropathic) and generalized/multicentric ALNH with neuropathy (POEMS-associated or neuropathic). The dichotomy between these two subtypes is not absolute, with considerable clinical overlap occurring among patients presenting with generalized disease. Immunophenotypic and molecular probe studies demonstrate clonal B-cell lymphocyte populations in some cases, particularly those with generalized/multicentric ALNH. However, the finding of clonal populations is of no value in predicting malignant clinical progression. We conclude that using this division of ALNH, patients presenting with symptoms and histomorphology consistent with ALNH can be subdivided into the appropriate category of ALNH. Localized or unicentric disease, either HV or PC subtype, has an excellent prognosis with surgery being curative in the majority of cases. Generalized or multicentric disease indicates a poor prognosis with short survival, with the neuropathic variant possessing resistance to steroids and chemotherapy and a corresponding worse prognosis.

Hodgkin's disease, mixed cellularity type, with a B-cell immunophenotype. Report of a case and literature review

The origin of the Reed-Sternberg cell, the neoplastic cell of Hodgkin's disease, has not been defined. We evaluated a case of Hodgkin's disease, mixed cellularity type, which presented in the retroperitoneum of a 45-year-old woman. Reed-Sternberg cells and Hodgkin's cells expressed the characteristic markers CD15 and CD30. In addition, they expressed the B-cell antigens CD19 and CD20, as well as CD45/leukocyte common antigen. Clonal rearrangement of the immunoglobulin heavy chain gene was detected by Southern blot analysis. These results suggest that some cases of Hodgkin's disease are derived from an activated cell of lymphoid origin. This case documents a close relationship between Hodgkin's disease and non-Hodgkin's lymphoma, and it demonstrates that even when newer ancillary techniques are employed these two entities can have overlapping features.

Primary low-grade hepatic B-cell lymphoma of mucosa-associated lymphoid tissue (MALT)-type

We describe the clinical, histological, and immunohistochemical features of four cases of primary low-grade B-cell lymphoma of the liver. The lymphomas were first seen as a solitary nodule in two patients and as two nodules in the third patient. These were found incidentally in an otherwise normal liver during abdominal surgery for other causes. In the fourth patient, several up to 2 cm nodules of lymphoma were found in a liver removed before transplant for chronic active hepatitis and cirrhosis. There was no evidence of lymphoma elsewhere in any of the patients. One patient has remained well, without evidence of lymphoma, 1 year after resection, one died intraoperatively, one is lost to follow-up, and the transplanted patient died 1 year after transplant from complications without evidence of recurrent lymphoma. The histology was typical of low-grade B-cell lymphoma of mucosa-associated lymphoid tissue (MALT)-type with centrocyte-like cells surrounding reactive B-cell follicles and forming lymphoepithelial lesions with bile ducts. Primary hepatic lymphomas are rare, and most reported cases have been high-grade B-cell lesions. The liver should be added to the list of extranodal sites where low-grade MALT lymphoma may occur.

Bladder and kidney cancer following cyclophosphamide therapy for non-Hodgkin's lymphoma

BACKGROUND

Cyclophosphamide is an established bladder carcinogen, but few studies have examined the relationship between dose and effect. The largest analysis to date included only seven cases of bladder cancer. No investigation has estimated the risk of kidney cancer.

PURPOSE

The purpose of this study was to quantify the risk of bladder and kidney cancer following cyclophosphamide therapy.

METHODS

Within a cohort of 6171 two-year survivors of non-Hodgkin's lymphoma (NHL), 48 patients with secondary cancer of the urinary tract were identified and matched to 136 control subjects with NHL who did not develop a second malignancy. Detailed information on chemotherapeutic drugs and cumulative dose received was collected for all subjects. Radiation dose to the target organ was estimated from individual radiotherapy records. Evaluations of the risk of second cancer as a result of treatment with cyclophosphamide alone, radiation alone, or both therapies were made relative to those patients who were exposed to neither treatment modality.

RESULTS

A significant 4.5-fold risk of bladder cancer (95% confidence interval [CI] = 1.5-13.6) followed therapy with cyclophosphamide, and risk was dependent upon cumulative dose. Among patients who received a total amount of cyclophosphamide of less than 20 g, a nonsignificant 2.4-fold risk of bladder cancer was apparent. Significantly elevated sixfold (95% CI = 1.3-29) and 14.5-fold (95% CI = 2.3-94) risks of bladder malignancy followed cumulative doses of 20-49 g and 50 g or more, respectively (P value for trend = .004). Radiotherapy given without cyclophosphamide was associated with a nonsignificant increased risk of bladder malignancy. Excess bladder cancer risk following treatment with both radiotherapy and cyclophosphamide was as expected if individual risks were summed. Neither radiotherapy nor cyclophosphamide was associated with excesses of kidney cancer.

CONCLUSIONS

Cyclophosphamide-related bladder cancer is dose dependent. For patients given cumulative doses between 20 and 49 g, the absolute risk of bladder cancer is on the order of three excess cancers per 100 NHL patients after 15 years of follow-up. At cumulative doses of 50 g or more, the excess risk increases to approximately seven excess bladder cancers per 100 NHL patients.

IMPLICATIONS

The strong dose-response relationship and high absolute risk of bladder cancer underscore the importance of limiting the cumulative dose of cyclophosphamide to what is required to achieve therapeutic end points. The risk of secondary bladder malignancy and other late sequelae of therapy must be carefully weighted against the curative gains provided by cyclophosphamide. Moreover, long-term side effects of therapy that might be acceptable in cancer treatment may need to be re-evaluated for patients with non-neoplastic disorders.

Extranodal lymphocyte predominance Hodgkin's disease. Clinical and pathologic features

Although B-cell nodular lymphocyte predominance Hodgkin's disease (nodular paragranuloma, LPHD) typically presents at low stage, reported series have identified a minor population of patients with advanced disease. Clinicopathologic findings in 13 cases of LPHD are described that had extranodal manifestations. The B-cell immunophenotype was confirmed in all cases with paraffin-section immunostains. Nine patients presented with extranodal disease; distribution was in Waldeyer's ring (n = 2), spleen (n = 3), spleen and liver (n = 3), or bone marrow (n = 1). Three cases, clinically stage III/IV at presentation, had involvement of bone marrow (n = 2) or bone marrow, liver and spleen (n = 1) at relapse. One patient presented with clinical stage IIe disease and had involvement of spleen at relapse. Follow-up was available for 11 patients (range 4 months to 11 years; mean, 5 years). One patient died of disease and one died with disease because of therapeutic complications. Six patients were disease-free and three had persistent or recurrent LPHD. Microscopically, LPHD was difficult to recognize in extranodal sites and could easily be mistaken for low-grade non-Hodgkin's lymphoma or conventional Hodgkin's disease. Certain morphologic and immunophenotypic findings were effective in avoiding such diagnostic confusion. Thorough staging evaluation appears warranted for LPHD because it may be responsive to therapy, even in advanced stage or after relapse. Although LPHD is unexpected in extranodal samplings, the wary pathologist can suspect its presence on the basis of characteristic histopathologic features. Confirmation of the diagnosis may require paraffinsection immunostains.

A clinical analysis of two indolent lymphoma entities: mantle cell lymphoma and marginal zone lymphoma (including the mucosa-associated lymphoid tissue and monocytoid B-cell subcategories): a Southwest Oncology Group study

The objectives of this study were (1) to determine the clinical presentation and natural history associated with two newly recognized pathologic entities termed mantle cell lymphoma (MCL) and marginal zone lymphoma (MZL), including the mucosa-associated lymphoid tissue (MALT) and monocytoid B-cell subcategories, and (2) to determine whether these entities differ clinically from the other relatively indolent non-Hodgkin's lymphomas with which they have been previously classified. We reviewed the conventional pathology and clinical course of 376 patients who had no prior therapy; had stage III/IV disease; were classified as Working Formulation categories A, B, C, D, or E; and received cyclophosphamide, doxorubicin, vincristine, prednisone (CHOP) on Southwest Oncology Group (SWOG) studies no. 7204, 7426, or 7713. All slides were reviewed by the three pathologists who reached a consensus diagnosis. Age, sex, performance status, bone marrow and/or gastrointestinal involvement, failure-free survival, and overall survival were compared among all the categories. We found that (1) MCL and MZL each represent approximately 10% of stage III or IV patients previously classified as Working Formulation categories A through E and treated with CHOP on SWOG clinical trials; (2) the failure-free survival and overall survival of patients with MZL is the same as that of patients with Working Formulation categories A through E, but the failure-free survival and overall survival of the monocytoid B-cell patients were higher than that of the MALT lymphoma patients (P = .009 and .007, respectively); and (3) the failure-free survival and overall survival of patients with MCL is significantly worse than that of patients with Working Formulation categories A through E (P = .0002 and .0001, respectively). In conclusion, patients with advanced stage MALT lymphomas may have a more aggressive course than previously recognized. Patients with MCL do not have an indolent lymphoma and are candidates for innovative therapy.

New characterization of infectious mononucleosis and a phenotypic comparison with Hodgkin's disease

Recent nucleic acid hybridization studies have implied that Reed-Sternberg/Hodgkin (RS/H) cells are infected with Epstein-Barr virus (EBV) before malignant transformation, and hence, that Hodgkin's disease could develop as a consequence of malignant transformation of an EBV-infected cell. This study is a detailed immunohistochemical and in situ hybridization characterization of the various lymphoid cells in nine cases of infectious mononucleosis (IM), the acute manifestation of EBV infection. The RS/H-like cells of IM were similar in most respects to their morphologically identical counterparts in Hodgkin's disease; they expressed the EBV-encoded protein LMP1, EBV EBER1 transcripts, and CD30 and rarely, if ever, expressed CD45/LCA or T cell markers. Dissimilarities were limited to CD15 negativity and the absence of a collarette of T cells around the RS/H-like cells of IM compared with their Hodgkin's counterparts. Expression of the immortalizing bcl-2 oncoprotein was variable in the RS/H-like cells of IM, as has been demonstrated in the RS/H cells of Hodgkin's disease by other investigators. An apoptosis assay suggested that many apoptotic cells in IM were EBV-infected T cells, in keeping with the previous in vitro observation that IM-derived T cells succumb to apoptosis. Additionally, the apoptosis assay suggested that RS/H-like cells of IM can succumb to programmed cell death, reminiscent of the mummified RS/H cells seen in Hodgkin's disease. The accumulation of evidence suggests that RS/H-like cells of IM are more similar to true RS/H cells than previously recognized.

Effects of barley yellow dwarf virus on the yield of winter wheat

Yield responses were measured of six winter wheats to field infections with Barley Yellow Dwarf Virus (BYDV). In addition to the natural incidence of virus, the range of infection levels was widened by aphicide spraying of some plots and the addition of artificially propagated viruliferous aphids to others. Significant grain yield losses attributable to natural infections by BYDV were found for all wheats despite the main infection period being in the spring. The addition of viruliferous aphids only marginally decreased yields further. Spraying with aphicides did not exclude infection but did reduce the incidence of BYDV and increase yields. A significant negative linear correlation between grain yield and percentage infection applied to each wheat genotype. The slope of the yield response appears to be a more useful measurement for comparing tolerance to BYDV of differing cereal lines than do proportional yield losses. Of the six wheats tested, Lawson, Birch 41, Birch 75, Owlet and Isis had similar tolerances to BYDV, despite substantial differences in absolute yields, while W71 was considerably more vulnerable. The mean natural incidence of BYDV in the main trial was 67%, producing an expected grain yield loss of about 2.2 t ha-1 for W71 and about 1.1 t ha-1 for the other five wheats. Effects on grain protein and potential control measures are also discussed.

A proposal for classification of lymphoid neoplasms (by the International Lymphoma Study Group)

A new classification of lymphoid neoplasms, mostly based on existing terminology, is proposed by the International Lymphoma Study Group. The proposed classification was reached through a consensus of the members, despite their diverse backgrounds, and consists of a listing of currently recognized clinicopathological entities. These tumours are divided into three major categories: B-cell neoplasms, T-cell and postulated natural killer cell neoplasms, and Hodgkin's disease. The characterization of each entity is based on a synthesis of all available information. This concept departs from a purely morphological approach to lymphoma classification, which is considered to be inadequate, because many biologically distinctive lymphoma types can exhibit a broad and overlapping morphological spectrum. Some entities are provisional, pending further data to confirm that their recognition is reproducible. The salient clinicopathological features of each entity are summarized in this review.

Risk of leukemia following treatment for non-Hodgkin's lymphoma

BACKGROUND

There have been few evaluations of the risk of acute nonlymphocytic leukemia (ANLL) following therapy for non-Hodgkin's lymphoma (NHL). Further, the relationship between cumulative dose of cytotoxic drug, radiation dose to active bone marrow, and the risk of ANLL following NHL have not been well described.

PURPOSE

Our purpose was to examine the risk of ANLL in relationship to all prior treatment for NHL.

METHODS

Within a cohort study of 11,386 2-year survivors of NHL, 35 case patients with secondary ANLL were identified and matched to 140 controls with NHL who did not develop ANLL. The primary eligibility criteria for the cohort included a diagnosis of NHL as a first primary cancer from January 1, 1965, through December 31, 1989; age 18 through 70 years at the time of initial diagnosis; and survival for 2 or more years without the development of a second invasive primary malignancy. Detailed information on chemotherapeutic drugs and radiotherapy was collected for all patients. Standard conditional logistic regression programs were used to estimate the relative risk (RR) of ANLL associated with specific therapies by comparing the exposure histories of case patients with individually matched controls.

RESULTS

Significant excesses of ANLL followed therapy with either prednimustine (RR = 13.4; 95% confidence interval [CI] = 1.1-156; P trend for dose < .05) or regimens containing mechlorethamine and procarbazine (RR = 12.6; 95% CI = 2.0-79; P < .05). Elevated risks of leukemia following therapy with chlorambucil were restricted to patients given cumulative doses of 1300 mg or more (RR = 6.5; 95% CI = 1.6-26; P < .05). Cyclophosphamide regimens were associated with a small, nonsignificant increased risk of ANLL (RR = 1.8;95% CI = 0.7-4.9), with most patients receiving relatively low cumulative doses (< 20,000 mg). Radiotherapy given at higher doses without alkylating agents was linked to a nonsignificant threefold risk of ANLL compared with lower dose radiation or no radiotherapy.

CONCLUSIONS

Our results suggest that prednimustine may be a human carcinogen, with a positive dose-response gradient evident for ANLL risk. The low, nonsignificant risk of leukemia associated with cyclophosphamide was reassuring because this drug is commonly used today. Despite the excesses of ANLL associated with specific therapies, secondary leukemia remains a rare occurrence following NHL. Of 10,000 NHL patients treated for 6 months with selected regimens including low cumulative doses of cyclophosphamide and followed for 10 years, an excess of four leukemias might be expected.

Mucous membrane plasmacytosis of the upper aerodigestive tract. A clinicopathologic study

We report 9 patients with an unusual plasma cell proliferative disorder of the upper aerodigestive tract. Six patients were men and three, women. The age at presentation ranged from 40 to 67 years with a mean of 54 years. Symptoms at presentation included dysphonia, dysphagia, difficulty breathing, and oral pain. These plasma cell lesions typically produced a cobblestone or warty appearance of the upper aerodigestive tract mucosa including the larynx, pharynx, palate, lips, mouth, tongue, and trachea in varying combination of multiple sites in each patient. Histologically, all lesions were characterized by psoriasiform epithelial hyperplasia with dyskeratosis and dense subepithelial plasmacytosis. Plasma cells were mature but so expansive and diffuse in infiltration as to suggest extramedullary plasmacytoma. Immunohistochemistry for kappa and lambda light chain showed polyclonal immunoglobulin content in all cases examined. Microbial cultures and Warthin-Starry stains were negative for organisms. A variety of treatments including antibiotic therapy, corticosteroid administration, and surgical resection were unsuccessful. In two patients, the process required tracheostomy. This disorder has not been previously described with the exception of a single reported case, which is included in this series. The etiology, pathogenesis, and successful management of mucous membrane plasmacytosis remain unknown.

Nodular lymphocyte predominance Hodgkin's disease. A distinct clinicopathological entity

This article reviews the evidence that the nodular form of lymphocyte predominance Hodgkin's disease ("nodular paragranuloma") should be recognised as a distinct clinico-pathological entity. The disease is characterised histologically by very large primary lymphoid follicles, containing polytypic small B lymphocytes and extensive meshworks of follicular dendritic cells. The "L and H" or "popcorn" cells scattered within the nodules show clear differences from classical Reed-Sternberg cells, both in their cytological appearance and in their marker profile, being frequently negative for CD15 and for the EBV genome, but often positive for B cell antigens, CD45 (leucocyte common antigen), CDw75 (LN1), epithelial membrane antigen (EMA) and J chain. These findings suggest that L and H cells may be Ig-synthesising monoclonal B cells. Nodular lymphocyte predominance Hodgkin's disease pursues a much more indolent courses that classical Hodgkin's disease, and long term survival is common. It has other distinctive clinical features, e.g. a unimodal age distribution, a predilection to involve single lymph nodes, and a very low incidence of thymic involvement. There is a tendency for diffuse large cell non-Hodgkin's lymphoma, usually of B cell type, to develop during the course of the disease. This type of Hodgkin's disease thus has many features that distinguish it from the nodular sclerosis and mixed cellularity varieties, and it is hoped that future studies will gather more information on its clinical behavior and on the nature of the putative neoplastic cells, as well as exploring different protocols for its treatment.

Epstein-Barr virus DNA is abundant and monoclonal in the Reed-Sternberg cells of Hodgkin's disease: association with mixed cellularity subtype and Hispanic American ethnicity

One hundred twenty-five cases of Hodgkin's disease from the United States (79), Mexico City (31), and Costa Rica (15) were analyzed for the presence of Epstein-Barr virus (EBV) by in situ hybridization to EBER1 transcripts. EBV was more frequently detected in the Reed-Sternberg (RS) cells of mixed cellularity Hodgkin's disease (37 of 48 [77%]) compared with the nodular sclerosis subtype (19 of 71 [27%], P < .001). The presence of EBV was also associated with Hispanic ethnicity (P < .001). In a multivariate analysis, patient age, gender, and geographic location were less predictive of EBV positivity than were mixed cellularity histology (odds ratio = 8.3) and Hispanic ethnicity (odds ratio = 4.3). Southern blot analysis of EBV terminal repeat fragments using the Xho1a probe showed that the viral DNA was monoclonal in 17 of 17 cases having EBER1-positive RS cells. By comparison, EBV DNA was not detected by Southern analysis in 20 cases lacking EBER1 in RS cells, even when occasional background lymphocytes expressed EBER1. Because clonal viral DNA was so readily detected in EBER1-positive cases, the EBV genome is probably amplified at least 50-fold in the infected RS cells. Monoclonality of EBV DNA implies that the RS cells were infected before malignant transformation.

Prognostic significance of the Ki-67-associated proliferative antigen in aggressive non-Hodgkin's lymphomas: a prospective Southwest Oncology Group trial

The growth fraction of tumors from patients with non-Hodgkin's lymphomas (NHL) has been shown to correlate with survival in retrospective studies. The growth fraction can be evaluated using immunohistochemical techniques employing the Ki-67 monoclonal antibody (MoAb) that marks a nuclear protein present in cycling cells. The purpose of this study was to evaluate the clinical utility of the Ki-67 MoAb for predicting survival. Using a prospective trial design in a multi-institutional cooperative trials group, the proliferative index, clinical outcome, and statistical correlations were independently assessed for previously untreated patients with advanced stages of intermediate- and high-grade histologies of NHL treated on Southwest Oncology Group study (SWOG 8516, Intergroup 0067). The proportion of Ki-67-positive cells was determined on snap-frozen thin tissue sections. A proliferative index of 80% or greater, as determined from prior retrospective studies, identified a group of patients (18%) who had a poor outcome. Overall survival was significantly reduced in these patients with a high Ki-67-associated proliferative index compared with those with a low proliferative index (P = .001). One-year survival estimates were 82% (low proliferative index) versus 18% (high proliferative index). A multivariate regression analysis incorporating commonly used clinical prognostic features confirmed the independent effect of proliferation on survival (relative risk estimate 5.9; 95% confidence interval, 2.2, 16.1). The Ki-67 MoAb identifies a group of patients with rapidly fatal NHL for whom currently available chemotherapy is inadequate.

Spontaneously generated non-Hodgkin's lymphoma in twenty-seven simian T-cell leukemia virus type 1 antibody-positive baboons (Papio species)

Simian T-cell leukemia virus type 1 (STLV-1), a type C retrovirus associated with leukemia/lymphoma in Old World monkeys, is closely related to human T-cell leukemia virus type 1, the etiologic agent of adult T-cell leukemia/lymphoma in humans. In a colony of 3200 baboons, the prevalence of antibodies to STLV-1 is more than 40%. Seropositivity is more frequent in female baboons than in males and increases with age. Of 27 STLV-1 antibody-positive baboons with non-Hodgkin's lymphoma, 20 were females and 7 were males, ranging in age from 3 to 21 years (mean, 13 years). Non-Hodgkin's lymphoma was not found in STLV-1 antibody-negative baboons. Clinical signs and laboratory findings were variable but generally included lethargy, low body weights, anemia, dyspnea, lymphadenopathy, hepatosplenomegaly, pneumonia, nodular skin lesions, and leukemia with or without multilobulated lymphocytes in peripheral blood. Radiography revealed pulmonary infiltrates consistent with pneumonia in 17 of the baboons. Serum chemical values were normal except for hypercalcemia in one baboon. Lymphocytosis was found in 18 of the baboons, with leukemia diagnosed in 11. At necropsy, variable enlargement of lymph nodes and other lymphopoietic tissue was usually found. Pale tan to white space-occupying foci typical of proliferative lymphoid tissue were often found in various organs, including lungs, spleens, livers, skin, and hearts. The lungs in 14 baboons had thickened pleuras, congestion,edema, and large tan to brown areas of consolidation.(ABSTRACT TRUNCATED AT 250 WORDS)