K.J. Gajl-Peczalska

Clinical characteristics of post-transplant lymphoproliferative disorders☆

PURPOSE To study the histopathologic findings, clinical course, and therapeutic outcome of patients who developed a lymphoproliferative disorder after undergoing solid organ transplantation. PATIENTS AND METHODS A series of 26 patients who developed a lymphoproliferative disorder after solid organ transplant during a 27-year period were studied. RESULTS The 26 patients ranged in age from 6 to 68 years (median 42 years). The lymphoproliferative disorder was diagnosed from 1 to 211 months (median 80 months) after transplantation. The type of transplant was kidney (n = 21), heart or heart-lung (n = 4), or liver (n = 1). Most patients received azathioprine and prednisone, in addition to antilymphocyte globulin or cyclosporine, for post-transplant immunosuppression. Eight patients had lymphoma that could be classified according to the International Working Formulation (IWF-F, IWF-G, IWF-H). Sixteen patients had polymorphic lymphoma, and 2 patients were classified as having polymorphic lymphoid hyperplasia. Patients were staged by the Ann Arbor staging system. Nine patients had stage I disease, 4 stage II, 6 stage III, and 7 stage IV. Central nervous system, lung, or marrow involvement was present in 27%, 23%, and 14% of patients, respectively. In the 17 patients studied, immunophenotype was monoclonal B-cell (n = 12), malignant T-cell (n = 2), or polyclonal B-cell (n = 3). The initial therapeutic approach was generally a reduction in immunosuppression, but, thereafter, the approach to therapy varied. In patients with localized disease, surgical excision and/or involved field radiotherapy were utilized as applicable. For patients with more extensive disease, other approaches such as high-dose acyclovir, combination chemotherapy, or alpha interferon were utilized. Overall, 15 of 26 patients (58%) responded to systemic therapy or were rendered disease-free either by surgery or radiation, including 8 (31%) with a complete remission (CR). Only 3 of 9 patients responded to chemotherapy, whereas 4 of 13 patients responded to acyclovir (including 3 patients who experienced CR). Remission duration ranged from 8 to 122 months (median 32+ months). Twenty-one of 26 patients (81%) have died. Survival ranged from less than 1 to 122 months (median 14 months). CONCLUSION The outcome of patients with post-solid organ transplant lymphoproliferative disorders is poor, and the optimal approach to therapy is not clear. Newer therapeutic approaches are thus needed to improve the outcome of these patients.

Epstein-Barr virus--determined clonality in posttransplant lymphoproliferative disease.

Analysis of the genomic termini of Epstein-Barr virus can provide valuable insight into the cofactor role of EBV in the development of B cell lymphomas and lymphoproliferative disease. We report EBV genomic findings in pathologic specimens from 10 patients who developed lymphoma or lymphoproliferative disease after renal or bone marrow transplantation. Endonuclease restriction patterns of EBV genomic termini are highly variable in size in both the episomal and linear configuration. This variability in fragment size permits direct assessment of tissue clonality in EBV-infected material. Hybridization with terminus-specific probes also reveals configuration of viral genome (circular and latent vs. linear and replicative). Nine of 10 patients had tumors with mono- or biclonal episomal markers, and 4 of 10 had evidence of linear or replicative virus. Analyses of virally determined markers were compared to immunoglobulin gene rearrangement studies, histologic immunophenotyping, cytogenetics, and clinical outcome. These 10 cases represent a spectrum of lymphoproliferative disorders ranging from benign polyclonal to malignant monoclonal disease. The molecular data lend credence to two important aspects of viral pathogenesis: (1) the finding of a homogeneous episomal population in the monoclonal tumors suggests that EBV infection is an early event in tumorigenesis that occurs before clonal expansion; and (2) therapeutic efficacy of acyclovir has been shown only in presence of polyclonal disease but may impact on intermediate stages where linear replicative virus can be found. Finally, the various assessments of tumor clonality were compared, and although heterogeneity was seen among patients and among diagnostic methods, analyses at the molecular level using virus and immunoglobulin gene specific probes were concurrent and provide the more sensitive means for detection of clonality.

IN-VITRO GLUCOCORTICOID STUDIES FOR PREDICTING RESPONSE TO GLUCOCORTICOID THERAPY IN ADULTS WITH MALIGNANT LYMPHOMA

Neoplastic tissues from 28 adults with malignant lymphoma were examined for glucocorticoid receptors and in-vitro sensitivity to glucocorticoids. The patients were then treated with desamethasone for 5--14 days. 13 patients achieved at least a partial remission, and 15 had no significant tumour response. Lymphoma cells from patients who responded had more glucocorticoid-receptor sites per cell and greater in-vitro sensitivity as measured by glucocorticoid inhibition of incorporation of leucine and uridine than did tumour cells from non-responders. Study of tumour glucocorticoid receptors and glucocorticoid sensitivity in vitro may allow selection of those patients with lymphoma who should receive glucocorticoids as part of combination chemotherapy.

Morphology of chronic lymphocytic leukemia and its relationship to survival

The morphology of lymphocytes in blood and bone marrow from patients with chronic lymphocytic leukemia was studied; blood lymphocyte morphology was related to survival. Three primary morphologic groups emerged. Group 1 was characterized by small to medium-sized lymphocytes with narrow rims of cytoplasm and coarsely clumped nuclear chromatin. In group II the predominant lymphocytes were large with abundant cytoplasm. Group III was characterized by a heterogeneous population of lymphocytes with characteristics of both groups I and II. Clinical features of the patients were studied, and B and T typing of the lymphocytes was done. The median survival in group I was 26+ months; in group II 46+ months; and in group III 50+ months. Our data are at variance with previous reports and suggest that survival in patients with large lymphocytes is longer than in those with small lymphocytes.

B-Cell Lymphoproliferative Disorders in Solid-Organ Transplant Patients: Detection of Epstein-Barr Virus by In Situ Hybridization

B-cell lymphoproliferative disorders (BLPDs) occur in approximately 2% of transplant recipients and are frequently fatal. Indirect serologic evidence has implicated Epstein-Barr virus (EBV) as an etiologic factor in these lesions. Direct evidence of the presence of EBV in these lesions has been obtained in relatively few cases. We used in situ hybridization (ISH) with a probe for the BamHI-W region of the EBV genome to study 52 tissue specimens from 28 solid-organ transplant patients who had BLPD. Epstein-Barr virus-infected lymphoid cells were identified in 26 of these 28 patients. The two patients without ISH evidence of EBV infection showed no distinctive clinical, morphologic, or serologic features. Previous filter-hybridization studies of these two patients had demonstrated evidence of EBV infection. Seven additional transplant patients without evidence of BLPD were studied as controls and showed no evidence of EBV in their lymphoid cells by ISH. These data provide further support for the etiologic role of EBV in the pathogenesis of posttransplantation lymphoproliferative disorders.

DIVERSITY OF PHENOTYPES OF NON-HODGKIN'S MALIGNANT LYMPHOMA

ABSTRACT Tumor masses from 100 patients with lymphoma were studied in both single cell suspensions and tissue frozen sections with a panel of 13 monoclonal antibodies and other lymphocyte marker assays (1). Various immunologic phenotypes were defined and they were compared with histologic classification. The diagnostic and biologic implications are discussed.

Laboratory preparation of a deglycosylated ricin toxin A chain containing immunotoxin directed against a CD7 T lineage differentiation antigen for phase I human clinical studies involving T cell malignancies

An immunotoxin consisting of a monoclonal antibody specific for CD7, a cell surface determinant expressed on T acute lymphocytic leukemia (T-ALL) blast cells, was linked to the potent plant toxin deglycosylated ricin toxin A chain (dgRTA) and is currently under evaluation in phase I clinical trials. Scale-up production of this immunotoxin, called DA7, was simplified using a two-step purification protocol that resulted in a highly purified immunotoxin meeting FDA criteria for IND approval. The anti-CD7 antibody, 3Ale, an IgG2b, was coupled to toxin using two different heterobifunctional cross-linkers, (1) N-succinimidyl-3-(2-pyridyl-dithiolproprionate) (SPDP), considered a standard croslinker and (2) 4-succinimidyloxycarbonyl-alpha-methyl-alpha-(2-pyridyldithio)tolu ene (SMPT), designed to hinder the in vivo breakdown of the toxin/antibody disulfide bond. Since experiments revealed that SPDP-DA7 had similar pharmacokinetics and biodistribution in mice and higher yields than DA7 made with a hindered cross-linker, SPDP-DA7 was scaled up for clinical study. Yield of SPDP-DA7 was 25% relative to starting material. Fractions were collected containing a toxin: antibody ratio of 1:1 to 4:1 rather than only a 1:1 ratio since studies showed that this heterogenous fraction was just as toxic to proliferating CD7-expressing leukemia cells as a homogeneous 1:1 fraction. In vitro, the concentration of heterogenous SPDP-DA7 selectively inhibiting 50% activity (IC50) of the CD7+ CEM cell line was 0.01 microgram/ml to 0.05 microgram/ml for inhibiting activated T cells or T cell lines. In vivo, SPDP-DA7 showed a significant anti-tumor effect against CEM cells administered to scid/scid mice, but even more importantly was effective against primary T cell leukemias taken from patients and injected into scid/scid mice.

Surface Markers Define Human Lymphoid Malignancies with Differing Prognoses

The lymphocyte is perhaps a unique cell in human biology because of the remarkable alterations in appearance and metabolic activity that result when activation occurs following antigenic stimulation (7). The activated lymphocyte has many of the metabolic and morphologic features generally observed in malignant cells. Because of these rapid and dramatic changes in appearance and activity as the cell changes from benign to belligerent, it is not surprising that a number of traps exist for individuals studying lymphoid diseases, and especially malignancies, with the microscope. Willis summarized the problem when he stated that “nowhere in pathology has a chaos of names so clouded clear concepts as in the subject of lymphoid tumors” (16). A new approach to the analysis of lymphoid malignancies was suggested by observations indicating the subsets of normal lymphocytes bear specific membrane-surface markers (7). In the past several years a significant body of evidence has been collected indicating that the surface phenotypes of normal lymphocytes are frequently retained in malignancies of lymphoid cells (9). The surface characteristics of human lymphoid malignancies as studied in our institution are the subject of this report.

Chromosome abnormalities in malignant lymphoma: biologic and clinical correlations.

Among the hematologic malignancies, the clinical and biologic significance of chromosome abnormalities have been most extensively studied in the acute leukemias and chronic myelogenous leukemia (CML). Clonal chromosome abnormalities are now identified in essentially all cases of CML and in most cases of acute nonlymphoblastic leukemia (ANLL) and acute lymphoblastic leukemia (ALL). In the acute leukemias, specific chromosome abnormalities have now been correlated with morphology (ANLL), immunologic phenotype (ALL), and various clinical features. In both ANLL and ALL, they have been found to be clinically important as independent risk factors for predicting response to treatment, remission duration, and survival [1–4].

Banded chromosome abnormalities in non-Hodgkin’s lymphoma. Correlations with morphology, immunologic phenotype and clinical course

Limited data are available regarding chromosomal abnormalities in malignant lymphoma, other than Burkitt’s. The few reported studies of banded chromosomes have generally been based on small series (less than 50 cases) and have often included many incomplete karyotypes. Bone marrow, blood or effusions have frequently been studied rather than lymph nodes or other primary tumor masses, and relatively few patients have been studied at diagnosis. Moreover, for a given lymph node, chromosome findings have rarely been correlated with histology and immunologic phenotype. Since July 1978, we have been prospectively studying chromosomal abnormalities in lymph nodes from patients with lymphoma and correlating them with histology, immunologic phenotype and clinical findings [1, 2]. In this manuscript we briefly review our findings in the first 115 patients.