HTLV-I-associated adult T cell leukemia/lymphoma in two patients from Bucharest, Romania

Two middle-aged patients with T cell lymphoma, both natives of Bucharest, Romania, tested positive for HTLV-I antibodies. Malignant cells had the typical phenotype and morphology of adult T cell leukemia/lymphoma (ATL). Both cases presented with extranodal manifestation, hypercalcemia, early recurrence after initial responses to therapy, and subsequent resistance to conventional and intensified chemotherapy. Infection with HTLV-I was confirmed by PCR analyses of serial biopsies. Neither patient reported known risk factors for HTLV-I infection. This report points to the possibility that Romania may represent an endemic area for HTLV-I and should heighten the awareness towards HTLV-I infections in Romanian patients.

Human T lymphotropic virus-1 infection

Human T lymphotropic virus-1 (HTLV-1) is a retrovirus which infects T lymphocytes (CD4+) to cause adult T cell leukaemia/lymphoma (ATL), tropical spastic para-paresis and several other HTLV-1 associated disorders. ATL has been reported worldwide but areas of high incidence include Japan (particularly the south-west), Central and South America, northern Iran, West and Central Africa and Melanesia. In the general Japanese population, HTLV-1 carriage is 0.1% but this can be as high as 50% in endemic areas. Six per 10000 carriers are estimated to progress to ATL each year. The three major routes of infection are mother to baby through breast-feeding, sexual intercourse and blood transfusion. There is a lengthy latency period of up to 40 years before the development of ATL. Up to 50% of ATL patients present with a cutaneous eruption. Diagnosis is established by the detection in lymphocytes of monoclonal integration of HTLV-1 proviral DNA. Even with aggressive treatment, ATL patients generally have a poor prognosis.

Adult T-cell leukemia with multiple lymphomatous polyposis of the gastrointestinal tract

A rare case of adult T-cell leukemia (ATL) in which multiple lymphomatous polyposis (MLP) was revealed throughout the entire gastrointestinal tract is reported here. The polypectomy specimens taken from the rectum revealed infiltration of neoplastic T-cells, the integration of HTLV-1 proviral DNA, and increased CD4 (OKT4) and CD25 (IL-2R) cells. The analysis of surface markers of the lymphocytes from polypoid lesions may be useful for elucidating cell tropism and homing properties in the gastrointestinal tract. Although MLP has always been associated with B-cell lymphoma in the Western world, it is important for clinicians and pathologists to be aware that MLP may be caused by the infiltration of ATL cells.

Gene therapy against retroviral diseases

Eventually, gene therapy may be a valid option for chronic viral infections, including retroviral infections. Human retroviral diseases fit two categories: (1) those that result from a monoclonal outgrowth of a human T-cell leukemia virus type I (HTLV-I)-infected cell, as in the case of adult T cell leukemia (ATL); and (2) those that appear to result directly from virus load rather than monoclonal outgrowth--such as tropical spastic paraparesis/HTLV-I associated myelopathy (TSP/HAM) and human immunodeficiency virus (HIV)-associated acquired immune deficiency syndrome (AIDS). For ATL gene therapy, corrective mechanisms directed at regulatory sequences rather than viral sequences may be most important, though perhaps anti-tax therapy would be useful. For TSP/HAM and AIDS, gene therapy directed to control virus replication may be most useful. For anti-retroviral therapy, one may use dominant negative mutants and a variety of other approaches that direct toxins or compete out viral regulatory gene signal sequences. For maximum benefit, such therapy should be directed to different essential genes (eg gag, pol, env, tat or rev) involved in the virus replication cycle and utilize different toxic approaches. A major impediment to the use of gene therapy for AIDS is our inability to transfect a significant fraction of target cells in vivo. Except for reconstituted mice, retroviral systems of animals have been under-utilized as models for gene therapy. Naturally occurring retroviral diseases of cats, goats, horses, and other species provide models for future development.

Hypercalcemia associated with adult T-cell leukemia/lymphoma (ATL)

Hypercalcemia is a frequent manifestation of human T-cell lymphotrophic virus type I (HTLV-I)-associated adult T-cell leukemia/lymphoma (ATL). Human T-cell lymphotrophic virus type I infection is endemic in the Caribbean, Japan, Melanesia, and Africa. This article presents two cases of ATL to increase awareness of the disease by primary care physicians. The management of hypercalcemia is discussed.

Resistance to APO-1 (CD95) induced apoptosis in T-ALL is determined by a BCL-2 independent anti-apoptotic program

Selective induction of programmed cell death, apoptosis, may represent a new approach to the treatment of cancer. Apoptosis can be induced by the monoclonal antibody anti-APO-1 directed against the cell surface receptor APO-1, a member of the nerve growth factor (NGF) receptor/tumor necrosis factor (TNF) receptor superfamily. We determined APO-1 expression and sensitivity to anti-APO-1 mediated apoptosis in childhood acute lymphoblastic leukemia cells of T lymphocyte precursor phenotype (T-ALL). APO-1 was constitutively expressed by 21 of 30 T-ALL and by all T-ALL cell lines investigated. However, most APO-1 positive T-ALL were resistant to anti-APO-1 mediated apoptosis. Sensitivity to anti-APO-1 mediated apoptosis was independent of the density of APO-1 expression on the cell surface and independent of the amount of Bcl-2. Incubation of resistant T-ALL with the protein synthesis inhibitor cycloheximide reversed resistance and induced sensitivity to anti-APO-1 mediated apoptosis in most T-ALL. These data suggest that resistance to anti-APO-1 mediated apoptosis in T-ALL is maintained by an active cellular program. Reversion of resistance to sensitivity towards induction of apoptosis in tumors may provide a new basis for successful therapeutic intervention.

Therapy with OKT3 monoclonal antibody in refractory T cell acute lymphoblastic leukemia induces interleukin-2 responsiveness

Administration of cytokines to patients with leukemia or lymphoma may recruit dormant malignant cells into cell cycle and thus make them more susceptible to chemotherapy. We treated a patient with refractory T cell acute lymphoblastic leukemia (ALL) with OKT3 monoclonal antibody and observed a dramatic but transient decrease of lymphoblasts. The T ALL cells were rather mature by morphology and immunophenotyping, expressing CD7, CD4, CD8 and CD3 surface antigens and nuclear TdT. Cytogenetic analysis revealed inversion of chromosome 14(q11q32.1). A total of 500 mg OKT3 (maximum dose 50 mg/day) was given. A decrease of lymphoblasts in the blood and a reduction of spleen size was observed. Complement levels dropped remarkably. Despite increasing serum levels of tumor necrosis factor, treatment was well tolerated overall. CD3 therapy induced strong IL-2 responsiveness of the lymphoblasts. Thus, OKT3 antibody treatment not only significantly decreased CD3-positive tumor cells, but also induced IL-2-mediated proliferation. This may also allow sequential application of CD3 and IL-2 to render certain T cell tumors more susceptible to chemotherapy.

APO-1 (CD95) mediated apoptosis in human T-ALL engrafted in SCID mice

The monoclonal antibody anti-APO-1 induces apoptosis upon triggering the cell surface molecule APO-1 (CD95), a novel member of the tumor necrosis factor/nerve growth factor receptor superfamily. We tested the efficacy of APO-1 mediated apoptosis in a model system of human leukemia in SCID mice. T-ALL cells recovered from SCID mice were sensitive towards anti-APO-1 mediated apoptosis when tested in vitro. In vivo, treatment of leukemia-bearing SCID mice with anti-APO-1 induced programmed cell death in a substantial fraction of T-ALL cells, thus leading to significantly prolonged survival. Anti-APO-1 treatment, however, failed to completely eliminate all leukemic cells. This may be due to resistance towards anti-APO-1 mediated apoptosis in a fraction of T-ALL cells. Thus, identification of cellular programs which determine sensitivity and resistance towards apoptosis may provide new perspectives for rational therapeutic interventions.

Infection of donor lymphocytes with human T lymphotrophic virus type 1 (HTLV-I) following allogeneic bone marrow transplantation for HTLV-I positive adult T-cell leukaemia

Human T lymphotrophic virus type 1 (HTLV-I) associated leukaemia has a poor prognosis even with chemotherapy. We describe a patient with adult T-cell leukaemia treated with allogeneic bone marrow transplantation from an HTLV-I negative identical sibling donor. During follow-up after bone marrow transplantation, HTLV-I could be repeatedly isolated inspite of anti-viral prophylaxis. The patient died of an acute encephalitis and HTLV-I could be detected in autopsy material from the brain. By a PCR-based technique using short tandem repeats (STRs) it was shown that the patient's haemopoiesis was of donor origin. This shows the infection of donor cells in vivo by an aetiological agent which has been implicated in the leukaemogenic process for adult T-cell leukaemia.

Immunophenotype of adult acute lymphoblastic leukemia, clinical parameters, and outcome: an analysis of a prospective trial including 562 tested patients (LALA87). French Group on Therapy for Adult Acute Lymphoblastic Leukemia

The aim of the multicentric trial LALA87 was to test the efficacy of different postremission therapies in adults (15 to 60 year olds) with acute lymphoblastic leukemia (ALL). An immunologic subclassification based on surface marker expression was proposed. Among the 562 tested patients, 511 were assigned either to the B lineage (361 cases, 63%) or to the T lineage (150 cases, 26%). T-ALL were significantly associated with male sex, age less than 35 years, mediastinal mass, central nervous system involvement, high white blood cell count, and low anemia. In a univariate and multivariate analysis, T-cell leukemia had a more favorable outcome than B-cell leukemia with respective median disease-free survivals (DFSs) of 28 and 14 months (P < .005). However, the type of postremission therapy modifies the value of the immunophenotype prognostic factor. In the chemotherapy arm, T-ALL patients (26 patients) had a more favorable outcome than B-ALL patients (57 patients) (P < .003). In the autologous bone marrow transplantation (ABMT) arm, the apparent better outcome of T-ALL patients (35 T/50 B) did not reach statistical significance (P = .2) and there was no difference in the allogeneic bone marrow transplantation (alloBMT) arm (37 T/71 B: P = .9). In the B-cell-lineage leukemias, subclassification by stages and myeloid antigen coexpression (10%) were not associated with different prognosis. CD10+ T-ALL (31 patients) were associated with a better DFS compared with the CD10- T-ALL (73 patients) with respective median DFS, not reached and 18.5 months (P = .04).

Recombinant alpha-2B interferon treatment for childhood T--lymphoblastic disease in relapse. A Pediatric Oncology Group Phase II study

BACKGROUND

Children with chemotherapy refractory T-cell lymphoblastic leukemia/lymphoma were given alpha-interferon (alpha-IFN) to evaluate the efficacy and toxicity of this biologic response modifier.

METHODS

Twenty children with T-cell acute lymphoblastic leukemia (T-cell ALL) in marrow relapse and one patient with mediastinal recurrence of T-cell non-Hodgkin's lymphoma (T-cell NHL) were enrolled. All patients had failed at least two previous multiagent drug trials. Recombinant alpha-IFN was given at 30 million U/M2/dose intravenously or subcutaneously for 10 doses over 14 days, followed by 3 doses per week until disease progression occurred.

RESULTS

One child had a complete response (< 5% blasts) and three patients a partial response (5-25% blasts) in their bone marrow. All patients eventually showed signs of progressive disease. Significant toxicities included cardiac hypofunction in two patients and profound lethargy in two patients.

CONCLUSIONS

alpha-IFN is tolerated in children with T-cell ALL and T-cell NHL and has activity against chemotherapy resistant disease.

Successfully treated optic nerve infiltration with adult T-cell lymphoma

A 45-year-old woman with adult T-cell leukemia had a sudden onset of decreased vision with central scotoma in the right eye. Right optic disc edema and thickening of the optic nerve were observed by magnetic resonance imaging. A diagnosis of leukemic infiltration to the optic nerve was made. A course of oral corticosteroid therapy was prescribed and 40 Gy of radiation was administered to the whole brain and right orbit. Her visual acuity recovered from finger counting to 20/20 within 3 weeks. We believe that this patient represents the first report of successfully treated optic nerve infiltration with adult T-cell leukemia caused by human T-lymphotropic virus type-I infection.

Advances in therapy for childhood non-B-lymphoblastic leukaemia

The majority of therapeutic gains for patients with ALL have come from prospectively planned clinical trials. Beginning in the 1970s, series of well-designed protocols have produced valuable information that has permitted the development of curative therapy for more than two-thirds of patients. This success emphasizes the importance of controlled, carefully analysed therapeutic studies, which pay dividends for many years by providing a sound basis for future developments. Experienced biostatisticians should be involved early in the development of clinical trials to ensure that research questions can be reliably answered in terms of the size and composition of the patient sample and in terms of accrual time. Despite extensive pre-planning, a protocol may require early termination due to unexpected results that compromise the integrity of the initial design (Rivera et al, 1985). Thus, periodic treatment assessment of the trial is crucial to a successful outcome. Extended follow-up of patients is a requirement in every leukaemia study since relapses may occur many years after diagnosis, especially if patients have a lower risk of treatment failure (Rivera et al, 1979). The quality of long-term survival must also be well documented because all protocols include toxic therapy (Ochs and Mulhern 1988). Every physician treating children with ALL would like to select therapy that is both effective and well tolerated. Unfortunately, this is not always possible when patients have high-risk features. Secondary AML, deaths in remission and fatal organ toxicity (Steinherz, 1991c) are equally devastating complications of current chemotherapy for ALL, and no single protocol can be recommended over any other. Patients with ALL may be equally well served by any of several different protocols. The practice of administering 6MP + MTX alone and usually orally as continuation treatment has been virtually abandoned. Today, most children receive intensified chemotherapy in one schedule or another, including good-risk patients on POG protocols who, although treated largely with antimetabolite-based programmes, receive high-dose chemotherapy during the initial 6 months of treatment. In view of the more favourable results attained with reinduction therapy in recent CCG studies, these investigators also recommend such an approach for children with better-risk ALL. We fully agree. Regrettably, with the success of current regimens for higher-risk ALL, it has not been possible to exclude all toxic agents that may induce serious late complications.(ABSTRACT TRUNCATED AT 400 WORDS)

Cimetidine-induced myelosuppression after bone marrow transplantation

A strong temporal correlation was observed between cessation of cimetidine and a sustained increase in blood counts in two marrow transplant recipients. Both were receiving cimetidine from the day of transplantation for prophylaxis of stress ulceration and gastritis. The blood counts of both patients were not increasing satisfactorily 5-6 weeks after marrow transplantation without any obvious cause of marrow suppression. A similar observation has been made with the use of ranitidine after marrow transplantation suggesting that histamine H2-receptor antagonists should be used very cautiously, if at all, in the setting of bone marrow transplantation.

Effectiveness of HB2 (anti-CD7)--saporin immunotoxin in an in vivo model of human T-cell leukaemia developed in severe combined immunodeficient mice

The transplantation of the human T-cell acute lymphoblastic leukaemia (T-ALL) cell line HSB-2 into severe combined immunodeficient (SCID) mice was found to produce a disseminated pattern of leukaemia similar to that seen in man. The intravenous injection of 10(7) HSB-2 cells was associated with a universally fatal leukaemia. Histopathological examination of animals revealed the spread of leukaemia initially from bone marrow to involve all major organs including the meninges. An immunotoxin (HB2-Sap) was constructed by conjugating the anti-CD7 MAb HB2 to the ribosome-inactivating protein saporin. An in vitro protein synthesis inhibition assay revealed specific delivery of HB2-Sap immunotoxin (IT) to CD7+ HSB-2 target cells with an IC50 of 4.5 pM. When SCID mice were injected with 10(6) HSB-2 cells and then treated 8 days later with a single intravenous dose of 10 micrograms of immunotoxin there was a significant therapeutic effect evidenced by the numbers of animals surviving in the therapy group compared with untreated controls (chi 2 = 5.348, P = 0.021). These results demonstrate the useful application of human leukaemia xenografts in SCID mice and the potential therapeutic effect of an anti-CD7 immunotoxin in human T-ALL.

Lymphokine receptors: a target for immunotherapy of lymphomas

Lymphoma cells often express lymphokine receptors that provide a target for therapy. For example, malignant cells of patients with HTLV-1-associated adult T-cell leukemia/lymphoma (ATL) express IL-2 receptors. In contrast, normal resting cells do not express the IL-2 receptors identified by the anti-Tac monoclonal antibody. Using the unmodified anti-Tac monoclonal antibody, one-third of the 19 patients treated with ATL have undergone a remission. However, unmodified murine monoclonal antibodies are limited by their immunogenicity and their poor effector functions. To address these issues, we used genetic engineering to produce humanized anti-Tac that contains the complementarity-determining regions from the mouse with the remainder of the antibody derived from human IgG1-kappa. Humanized anti-Tac is dramatically less immunogenic than the murine versions and, in contrast to the parent antibody, manifests antibody-dependent cellular cytotoxicity with human mononuclear cells. To enhance its effector function, anti-Tac was armed with toxins or with alpha- and beta-emitting radionuclides. In a clinical trial with 90Y-anti-Tac, 11 of the 17 patients with ATL underwent a partial or sustained complete remission. Thus, the clinical application of lymphokine-receptor-directed therapy provides a new perspective for treatment of certain lymphomas, including HTLV-1-associated ATL.

Immunotoxin studies in a model of human T-cell acute lymphoblastic leukemia developed in severe combined immune-deficient mice

The transplantation of the human T-cell acute lymphoblastic leukemia (T-ALL) cell line HSB-2 into severe combined immune-deficient (SCID) mice was found to produce a disseminated pattern of leukemia similar to that seen in humans. The iv injection of 10(7) HSB-2 cells was associated with a universally fatal leukemia. Histopathological examination of animals revealed the spread of leukemia initially from bone marrow to involve all major organs including the meninges. An immunotoxin (HB2-Sap) was constructed by conjugating the anti-CD7 monoclonal antibody (MAb) HB2 to the ribosome inactivating protein (RIP) saporin. An in vitro protein synthesis inhibition assay revealed specific delivery of HB2-Sap immunotoxin (IT) to CD7+ HSB-2 target cells with an IC50 of 4.5 pM. In an in vivo study, the IT was shown to significantly prolong the survival of SCID mice injected with HSB-2 cells compared to untreated control animals. This therapeutic effect was seen both with a single injection of 10 micrograms of IT given 7 d after the injection of HSB-2 cells, and was even more effective when IT was administered as three daily injections of 10 micrograms on d 7, 8, and 9. These results demonstrate the useful application of human leukemia xenografts in SCID mice and the potential therapeutic effect of an anti-CD7 IT in human T-ALL.

Transfusion-associated graft-versus-host disease--report of two further cases with an immunohistochemical analysis

Transfusion-associated graft-vs.-host disease (tGVHD) is a severe disease usually affecting immunocompromised hosts with haematological neoplasia. Two patients with acute leukaemia are reported, who developed fatal tGVHD after blood transfusions. Intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1) and endothelial leucocyte adhesion molecule 1 (ELAM-1) expression and the CD4/CD8 ratio were assessed in lesional skin. ICAM-1 was strongly expressed on epidermal keratinocytes and endothelial cells (EC) and correlated with HLA-DR staining. VCAM-1 was strongly expressed on EC in the superficial dermal vessels. ELAM-1 stained weakly on EC in some of the superficial vessels. CD8+ lymphocytes showed prominent epidermotropism; the CD4/CD8 ratio was 0.8 in case 1 and 1.2 in case 2. Infiltrating cells were positive for CD3, CD11a, and CD18. Langerhans' cells were almost completely absent. The dermatologist must be aware of the importance of such a rare, unexpected and almost always fatal complication of blood transfusion, in order to make an early diagnosis. Irradiation of blood products is the only effective way to prevent tGVHD in all subjects at risk.

Anti-IL-2 receptor monoclonal antibody (anti-Tac) treatment of T-cell lymphoma

The abnormal and activated T cells in certain neoplasms of mononuclear cells, select autoimmune disorders, and organ allograft rejection express the IL-2R alpha subunit identified by the anti-Tac monoclonal antibody. In contrast, normal resting cells do not express this inducible receptor. Patients with ATL were treated with different forms of IL-2R-directed therapy to exploit the difference in IL-2R expression between normal and malignant cells. Using the unmodified anti-Tac monoclonal antibody, 7 of 19 patients with ATL treated have undergone a remission (2 cases complete), with no toxicity observed. Unmodified murine monoclonal antibodies are limited by their immunogenicity and poor effector functions. Genetic engineering was used to produce humanized anti-Tac that contains the complementarity-determining regions from the mouse with the remainder of the molecule derived from human IgG1-kappa. This antibody is less immunogenic than the murine version, has improved pharmacokinetics, and, in contrast with the parent antibody, manifests ADCC with human mononuclear cells. To enhance its effector function, anti-Tac was armed with toxins or with alpha- and beta-emitting radionuclides. In a clinical trial with 90Y-anti-Tac at the doses used (5, 10, and 15 microCi), 11 of the 17 patients with ATL underwent a partial or sustained a complete remission. Thus, the clinical application of IL-2R-directed therapy represents a new perspective for the treatment of T-cell lymphomas, including HTLV-I-associated ATL.

Occlusive microvascular retinopathy with optic disc and retinal neovascularization in acute lymphocytic leukemia

BACKGROUND

Acute lymphocytic leukemia can be associated with an occlusive microvascular retinopathy. There is a potential for worsening of this occlusive microvascular retinopathy by radiation damage to the retinal vasculature (radiation retinopathy) and by the toxic effects of chemotherapy.

METHODS

An 18-year-old woman with T-cell acute lymphocytic leukemia received low-dose irradiation to the brain and subsequent chemotherapy, which included cytosine arabinoside.

RESULTS

During the chemotherapy, she developed severe bilateral occlusive microvascular retinopathy that progressed despite extensive panretinal photocoagulation to bilateral optic disc and retinal neovascularization and eventual traction retinal detachment involving the macula.

CONCLUSION

The toxic effect of a chemotherapeutic agent such as cytosine arabinoside when combined with radiation retinopathy may be additive, leading to a much more severe ischemic retinal vasculopathy than one would encounter with acute lymphocytic leukemia alone. This must be kept in mind when planning combined radiation and chemotherapy for T-cell acute lymphocytic leukemia.

Successful pregnancy in a 28-year-old patient autografted for acute lymphoblastic leukemia following myeloablative treatment including total body irradiation

We report a successful pregnancy in a woman who at the age of 28 years received total body irradiation (TBI; 7.5 Gy) and high-dose chemotherapy prior to autografting of purged bone marrow for acute lymphoblastic leukemia. Four years after transplantation she delivered a healthy girl. Only five previous cases of successful pregnancies are described in the literature after conditioning regimens including TBI. This case shows that restored ovarian function is possible after TBI in spite of prolonged exposure to chemotherapeutic agents during induction and consolidation therapy and relatively high age at the time of transplantation.

Severe adenoviral nephritis following bone marrow transplantation: successful treatment with intravenous ribavirin

Invasive adenovirus infection is recognized as an unusual cause of serious end-organ sequelae following BMT. Because symptomatic therapy may be inadequate for more serious infections, the use of investigational agents is justified. We describe a case of severe, progressive nephritis secondary to adenovirus serotype 11 following BMT. Treatment with i.v. ribavirin led to prompt clinical improvement and resolution of adenovirus excretion.

The interleukin-2 receptor: a target for monoclonal antibody treatment of human T-cell lymphotrophic virus I-induced adult T-cell leukemia

Adult T-cell leukemia (ATL) is a malignancy of mature lymphocytes caused by the retrovirus human T-cell lymphotrophic virus-I (HTLV-I). It is an aggressive leukemia with an overall mortality rate of 50% within 5 months; no conventional chemotherapy regimen appears successful in inducing long-term disease-free survival in ATL patients. However, ATL cells constitutively express high-affinity interleukin-2 receptors (IL-2Rs) identified by the anti-Tac monoclonal antibody, whereas normal resting cells do not. To exploit this difference in receptor expression, we administered anti-Tac intravenously (IV) to 19 patients with ATL. In general the patients did not suffer untoward reactions, and in 18 of 19 cases did not have a reduction in normal formed elements of the blood. Seven patients developed remissions that were mixed (1 patient), partial (4 patients), or complete (2 patients), with partial and complete remissions lasting from 9 weeks to more than 3 years as assessed by routine hematologic tests, immunofluorescence analysis, and molecular genetic analysis of T-cell receptor gene rearrangements and of HTLV-I proviral integration. Furthermore, remission was associated with a return to normal serum calcium levels and an improvement of liver function tests. Remission was also associated in some cases with an amelioration of the profound immunodeficiency state that characterizes ATL. Thus the use of a monoclonal antibody that blocks the interaction of IL-2 with its receptor expressed on ATL cells provides a rational approach for treatment of this aggressive malignancy.

Augmentation of in vitro cytolytic activity of LAK cells with heated ATL-derived cell lines

Three adult T-cell leukemia/lymphoma-derived cell lines, MT-2, MJ, and HUT102, were investigated to determine how they responded to hyperthermia, lymphokine-activated killer (LAK) cells, or a combination of both in vitro. All three cell lines showed a similar sensitivity to LAK cells, but revealed varying degrees of sensitivity to hyperthermia (MT-2 < MJ < HUT102) by 51Cr release assay. Hyperthermia did not cause immediate cell death as determined by the trypan blue exclusion test, but did cause substantial decreases in the numbers of heated cells within 2 days. The density of the cells began to increase thereafter, which was consistent with the results of the experiments labeling the cells with 3H-TdR after hyperthermia. When the cells were heated at 39-43 degrees C for 1-3 hr and then interacted with various LAK cell/ATL cell (E/T) ratios at 37 degrees C for 4 hr, total cytolysis of the cells increased in a synergistic and/or additive manner over that of the cells without hyperthermia. Prolonged incubation of the cells at high temperature did not necessarily cause a large increase in the interaction of LAK cells after hyperthermia. This augmentation of cytolysis by LAK cells after hyperthermia was not seen in normal peripheral lymphocytes. These results suggest that the combination therapy of hyperthermia and LAK cells may be more specific, useful, and effective for treating malignant lymphoma.

1992 Stohlman Memorial Lecture: targeting the IL-2 receptor

Patients with human T-cell lymphotropic virus I (HTLV-I)-associated leukemia/lymphoma were treated with different forms of IL-2 receptor (IL-2R)-directed therapy that exploit the difference in IL-2R expression between normal and malignant cells. Using unmodified anti-Tac monoclonal antibody, one-third of the patients with adult T-cell leukemia (ATL) treated have undergone a remission, in two cases complete. There was little toxicity observed; however, unmodified monoclonal antibodies are limited by their immunogenicity and their poor effector functions. To address these issues, "humanized" anti-Tac was produced that contains the complementarity-determining regions from the mouse with the remainder of the molecule derived from human IgG1 kappa. This antibody is dramatically less immunogenic than the murine version, has improved pharmacokinetics, and, in contrast to the parent antibody, manifests antibody-dependent cellular cytotoxicity (ADCC). To enhance its effector function, anti-Tac was armed with toxins and alpha- and beta-emitting radionuclides. In a clinical trial of 90Y-anti-Tac in ATL patients, at the doses used (5, 10, and 15 mCi 90Y-anti-Tac per patient), 10 of the 15 patients with ATL treated to date underwent sustained partial or complete remission. Thus, the clinical application of IL-2R-directed therapy represents a new perspective for the prevention of allograft rejection and for the treatment of graft-versus-host disease, select autoimmune disorders, and leukemia/lymphoma.

Cytotoxic activities of recombinant immunotoxins composed of Pseudomonas toxin or diphtheria toxin toward lymphocytes from patients with adult T-cell leukemia

We have previously shown that the recombinant single-chain immunotoxin anti-Tac(Fv)-PE40, composed of the variable domains of the anti-Tac monoclonal antibody in a single-chain form joined to a derivative of Pseudomonas exotoxin (PE), is cytotoxic toward malignant cells from adult T-cell leukemia (ATL) patients. Using this assay, we have now compared the activity of anti-Tac(Fv)-PE40 with that of an improved version, anti-Tac(Fv)-PE40KDEL which contains an altered carboxyl terminus, and also with two chimeric toxins made with diphtheria toxin (DT). One of these is a fusion of amino acids 1-388 of DT with anti-Tac(Fv) and is termed DT388-anti-Tac(Fv). The other, DT388-IL2, contains interleukin 2 (IL2) at the carboxyl terminus of the same DT derivative. We incubated these toxins with malignant ATL peripheral blood mononuclear cells (PBMCs) for 1-3 days and then measured [3H]leucine incorporation. We found that anti-Tac(Fv)-PE40KDEL was the most cytotoxic agent and was followed in decreasing order of activity by anti-Tac(Fv)-PE40, DT388-anti-Tac(Fv), and finally DT388-IL2. Trypan blue staining showed that inhibition of protein synthesis correlated with cell death. Time course studies showed that the recombinant toxins containing anti-Tac(Fv) were cytotoxic even if exposed to the cells for only one hour. After intravenous injection into mice, the half-life of anti-Tac(Fv)-PE40 or anti-Tac(Fv)-PE40KDEL was 30 minutes. Normal PBMCs were resistant to all four toxins. Recombinant immunotoxins made with anti-Tac merit further study as potential reagents in the treatment of ATL.

Characteristics of pro-T ALL subgroups: comparison with late T-ALL. The Groupe d'Etude Immunologique des Leucémies

A group of 30 acute lymphoblastic leukemias (ALL) with the early pro-T phenotype CD7+/cCD3+/CD1-/CD3-/CD4-/CD8-were identified among 103 newly diagnosed ALL with T-lineage markers (T-ALL). Pro T-ALL was more often observed in adults, and showed a lower incidence of hyperleukocytosis than more mature T-ALL. Mediastinal masses and polar acid phosphatase positivity in blast cells were however observed with the same frequency in pro T-ALL and late T-ALL, and rearrangements of both T-cell receptor (TCR) beta and gamma genes were observed in half the pro T-ALL cases tested. The expression of CD34, DR, and myeloid (My) markers was significantly more frequent in pro T-ALL than in late T-ALL, and these three features were strongly linked. TCR gene rearrangements were two to three times more frequent in CD34- and My-pro T-ALL. However, both CD34+ and My+ pro T-ALL showed an incidence of mediastinal masses and polar acid phosphatase positivity similar to this observed in CD34- and My- cases. This supports the assumption that both types of ALL indeed are engaged in the T-lineage, and confirms intracytoplasmic cCD3 as the earliest marker for this lineage. Moreover, CD34 appears to persist up to an early stage of T-cell maturation, where the cells retain myeloid potentiality. Loss of CD34 correlates with TCR-beta gene rearrangement and definitive commitment to the T lineage. Event-free survival analysis suggested a poorer outcome for pro T-ALL in adult patients.

Prognostic significance of myeloid-associated antigen expression on blast cells in children with acute lymphoblastic leukemia. The Austrian Pediatric Oncology Group

The prognostic significance of expression of myeloid-associated antigens in childhood acute lymphoblastic leukemia (myA+ALL) was evaluated. From 1984 to 1990, 251 children with immunologically verified ALL were treated in two prospective consecutive Austrian studies. Complete immunophenotyping was performed in 206 cases (82%). Out of these 175 cases were classified as B-cell precursor ALL, 31 cases as T-ALL. Expression of myeloid-associated antigens was demonstrated in 23 cases (13.1%) of childhood B-cell precursor ALL, particularly in immature (CD10 negative) forms (P < .0001), and in 1 case (3.2%) of T-ALL. CDw65 was expressed most frequently (12 cases), followed by CD13 and CD15 (5 cases each), CD33 (4 cases), and blood-group H (3 cases). Compared to myA- ALL prognosis of children with myA+ B-cell precursor ALL was poor, despite intensive multiagent chemotherapy according to BFM protocols. Remission rates were not impaired, but pEFS was 74.6% for myA- ALL, and only 37.8% for myA+ ALL (P = .0001). As demonstrated by multivariate analysis the expression of myeloid-associated antigens was the most important prognostic variable for EFS in B-cell precursor ALL, whether or not CD10 was expressed.

Biodistribution and in vivo antitumor efficacy of the systemically administered anti-human T-leukemia immunotoxins and potentiation of their efficacy by alpha-interferon

In this study, the systemically administered anti-human T-leukemia immunotoxins (ITs) are shown to be effective for tumor suppression in Ichikawa T-leukemia-bearing nude mice. In addition, their antitumor efficacy was markedly potentiated by recombinant human IFN-alpha. The combination of ITs and IFN-alpha effectively killed the tumor in the majority of the treated mice; 9 of the 12 treated mice survived tumor-free for as long as they were followed, i.e. for 140 days. Two different ITs, SN1-ricin A chain (RA) and SN2-RA, were used together to minimize the problem of tumor heterogeneity; monoclonal antibodies SN1 and SN2 are directed toward two different human T-leukemia associated cell surface antigens. In the biodistribution experiments, the paired label technique was used to include a reliable internal control. In an experiment, equal amounts of 125I-SN1-RA and 131I-labelled isotype-matching control IgG (IgG1-kappa)-RA were mixed and administered i.v. into tumor-bearing nude mice. In a separate experiment, a mixture of equal amounts of 125I-SN2-RA and 131I-control IgG-RA was administered i.v. This technique allowed us to distinguish the immunospecific uptake from the non-immunospecific uptake of ITs into individual organs. The present results clearly show that both SN1-RA and SN2-RA are specifically localized in tumors after systemic administration. For instance, 24 h after the administration of a radiolabelled mixture, the ratio of 125I/131I in the tumor was 7.0 and 23.5, respectively, for the SN1-RA/control IgG-RA mixture and the SN2-RA/control IgG-RA mixture. Such high ratios of 125I/131I were detected in the tumors throughout the experiments between 30 min and 24 h after the administration of the paired label mixture.

Cytotoxicity of CD3-ricin A chain immunotoxins in relation to cellular uptake and degradation kinetics

The cytotoxicity of WT32 (CD3)-ricin A immunotoxin (IT) to the acute lymphoblastic leukemia T-cell line Jurkat was compared with the rate of internalization and intracellular degradation of WT32 and WT32-ricin A during continuous exposure. Moreover, the influence of NH4Cl and monensin on these processes was studied. Based on protein synthesis inhibition ([3H]leucine incorporation), it appeared that cytotoxicity was not fully expressed directly after exposure to IT due to a delay in either the internalization of membrane-bound IT or the action of intracellular ricin A. Varying the duration of incubation and postponing [3H]leucine addition for up to 24 h after initiation showed that cytotoxicity occurred in two phases, rapid internalization of initially bound IT followed by a continuous but slower uptake, possibly due to reexpression of the CD3 antigen. No differences were found in the rate of internalization and degradation of 125I-labeled WT32 and WT32-ricin A. Internalization started rapidly after binding at 37 degrees C, was fastest during the first 12 h (+/- 360,000 molecules/cell), and continued for at least 24 h (+/- 420,000 molecules/cell). Exocytosis of intracellularly degraded molecules became measurable after 1 to 2 h of incubation at 37 degrees C and increased to approximately 400,000 molecules/cell in 24 h. After 4 h of incubation at 37 degrees C the number of internalized molecules exceeded the amount of WT32 that could maximally bind to the cell membrane (+/- 150,000 molecules/cell), confirming reexpression of antigen. The addition of NH4Cl and monensin enhanced the cytotoxicity of WT32-ricin A, probably due to an increased intracellular amount of IT. These agents appeared to reduce strongly the degradation of internalized WT32, resulting in an accumulation of intracellular molecules. NH4Cl was most effective during the first 12 h of incubation, whereas monensin increased the amount of intracellular WT32 molecules after 2 to 24 h. Our observations suggest that incubation conditions for the optimal cytotoxicity of IT treatment can be predicted by studying the internalization and degradation of the IT or respective monoclonal antibody.

T-cell leukemia-lymphoma and mycosis fungoides

Notable efforts have been made to relate aspects of the cell biology of T cells to the pathology, diagnosis, and treatment T-cell neoplasms. In particular, the application of molecular biologic tools to these areas has already allowed the generation of patient-specific markers for disease. A case can be made that a knowledge of the distinctive natural history of T-cell neoplasms should influence choices of treatment. Additional insights into the relevance of the human T-cell leukemia-lymphoma virus family to human disease have been recorded, and an important association of cutaneous T-cell lymphoproliferative disorders with human immunodeficiency virus infection has been documented.

Tumour lysis following hydrocortisone prior to a blood product transfusion in T-cell acute lymphoblastic leukaemia

The acute tumour lysis syndrome is a well recognised complication of chemotherapy for lymphoid malignancies. There are few reports, however, of this complication after corticosteroid therapy alone. We report a case of T-cell acute lymphoblastic leukaemia who developed the biochemical picture of tumour lysis after two doses of hydrocortisone given prior to platelet transfusion. Prophylactic corticosteroids prior to blood product infusion should be reserved for patients who have experienced febrile or allergic reactions in the past and it is suggested that they should only be administered to patients with active lymphoid malignancies with due caution.

Growth and spread of human malignant T lymphoblasts in immunosuppressed nude mice: a model for meningeal leukemia

Previous work has shown that nude (nu/nu) mice additionally immunosuppressed by splenectomy, sublethal irradiation, and treatment with antiasialo GM1 antiserum (SIA-nu/nu mice) have no detectable natural killer activity and allow the growth of human malignant lymphoblasts. We show here that all SIA-nu/nu mice engrafted intravenously with 5 x 10(6) malignant lymphoblasts originally derived from a child with a T-cell acute lymphoblastic leukemia (PF382) and from a boy with a T-cell lymphoma (ST-4) develop lethal meningeal leukemia and die within 35 days. Histologic examination of moribund SIA-nu/nu mice showed that vertebral and skull bone marrow was always replaced by proliferating human T lymphoblasts. From the spinal canal, lymphoblasts spread to the meninges, causing hind leg paralysis. Leaving the skull, they permeated the meninges and then invaded the nervous parenchyma. This efficient and reproducible experimental model may be suitable for experimental studies on the pathogenesis of meningeal leukemia.

Superior vena cava syndrome associated with lymphoma

OBJECTIVE

To evaluate the workup and treatment of children with lymphoma and superior vena cava syndrome.

DESIGN

A retrospective survey.

SETTING

State hospital serving as a secondary and tertiary referral center for pediatric oncology and pediatric cardiac surgery.

PARTICIPANTS

Eleven children aged 11 months to 12 years diagnosed as having lymphoma or T-cell acute lymphoblastic leukemia who presented with superior vena cava syndrome during an 11-year period.

INTERVENTIONS

Lymph node biopsy (two patients), thoracenthesis (five patients), bone marrow aspiration (two patients), and thoracenthesis in addition to bone marrow aspiration (two patients). All aspirates were evaluated with immunohistochemical studies. Chemotherapy was the only management intervention.

RESULTS

T-cell lymphoma or leukemia accounted for nine cases and Hodgkin's disease for two cases. Respiratory symptoms occurred in 10 patients, including tracheal compression in six patients (compression was life-threatening in one patient). Diagnosis of superior vena cava syndrome was achieved in eight patients using surface-marker analysis of aspirates. The syndrome disappeared within 2 to 10 days. Seven of nine children whose conditions were diagnosed more than 1 year before this writing were alive and free of disease after mean follow-up of 37 months.

CONCLUSIONS

(1) A specific diagnosis can be achieved in most children with superior vena cava syndrome and lymphoma; (2) Thoracic computed tomographic scans are essential, identifying minute pleural effusions that can aid diagnosis; (3) Anesthetic hazard is related only to severe tracheal compression; (4) Chemotherapy achieves excellent symptomatic relief; and (5) Long-term survival, without disease, is achievable.

Cell-targeted 114Inm and drug (BCNU) combination therapy in a rat acute lymphoblastic leukaemia

A proportion of syngeneic female rats inoculated intramuscularly with a lethal T-cell lymphoblastic (Roser) leukaemia are cured by a single intraperitoneal injection of bischloroethylnitrosourea (BCNU) (Carmustine) (10 mg kg-1) given towards the end of the preleukaemic phase (day 7). Additional therapy on day 4, using intravenous leukaemia cells lethally labelled with the radionuclide 114Inm, enhanced the overall cure rate by 30%. The spleen is a major site of indium concentration from the targeting cells so that the continuous local radiation field appears to result in a substantial reduction of the body load of leukaemia cells in the enlarged spleen particularly, thus enhancing the curative potential of the drug. The results demonstrate in principle that in patients in remission a single dose of targeted radiotherapy in the spleen combined sequentially with an appropriate drug might provide considerable aid in eliminating a residual population of leukaemia cells.

Acute adult T-cell leukemia/lymphoma presenting with florid cutaneous disease

Adult T-cell leukemia/lymphoma (ATLL) is characterized by cutaneous disease, hypercalcemia, associated HTLV-I infection, and a fulminant course refractory to therapy. A patient with acute ATLL is described, and the natural history of ATLL is reviewed.

Frequency and DNA sequence of tal-1 rearrangement in children with T-cell acute lymphoblastic leukemia

Using nested polymerase chain reaction (PCR) a gene rearrangement named tal-1 deletion was found in five of 56 leukemic bone marrow samples from children with T-cell acute lymphoblastic leukemia (ALL). The DNA sequences of the PCR fragments consisted of the known conserved germline sequences in addition to short DNA insertions at the breakpoint region, which were different in each patient. Moreover, one patient was examined at diagnosis and at relapse 11 months later, revealing identical DNA sequences at the rearrangement site. The recombination site of the tal rearrangement therefore may be used as a genetic marker for detecting minimal residual disease in about 10% of T-cell ALL in childhood.

Efficacy of an anti-CD7-ricin A chain immunoconjugate in a novel murine model of human T-cell leukemia

In vivo efficacy testing of monoclonal antibody-based drugs specific for human leukemias is hampered by the paucity of suitable animal models, due in part to the inability of many anti-human monoclonal antibodies to cross-react with antigens expressed in animal tissues or cells. Moreover, human leukemic cells have proven difficult to establish in immunosuppressed mice except as solid tumors. We report here the establishment of a murine model for human leukemia displaying features of human disease, such as growth of malignant cells and localization of such cells to lymphoid compartments, and the effective depletion of leukemic cells from these mice by an immunoconjugate. Human T-leukemia cells (CEM) injected into cyclophosphamide-pretreated NIH-III mice engrafted in all mice (n = 41), with CEM cells detected in the bone marrow, spleen, and blood 4 weeks after injection. There was no evidence of solid tumors. Treatment of CEM-engrafted mice with 4A2-RTA30, an immunoconjugate of an anti-CD7 monoclonal antibody and ricin A chain (RTA30), resulted in a 100- to 200-fold overall depletion of CEM cells from the spleen and the bone marrow (P less than 0.02). This depletion was specific and toxin-dependent, as a control immunoconjugate had no demonstrable effect (P greater than 0.5). Depletion of CEM cells was also observed after treatment with unconjugated anti-CD7 mAb, but this effect was not significantly different from controls (P greater than 0.1). Therefore, significant depletion of CEM cells required the presence of the ricin A chain moiety. Further investigations revealed that CEM cells recovered from NIH-III mice expressed less CD7 antigen, but remained sensitive to subsequent in vitro exposure to 4A2-RTA30. In conclusion, we have established a model for studying the efficacy of immunoconjugates and have successfully depleted human T-leukemic cells from lymphoid tissues in immunodeficient mice by treatment with an anti-CD7-RTA30 immunoconjugate.

Successful treatment of human acute T-cell leukemia in SCID mice using the anti-CD7-deglycosylated ricin A-chain immunotoxin DA7

The study of new therapeutic approaches for refractory human leukemia has been hampered by the lack of relevant in vivo models with disseminated disease, particularly T acute lymphoblastic leukemia (T-ALL). In the present study we evaluated methods for establishing and therapy of a human T-ALL cell line (MT-ALL) in 73 SCID mice. MT-ALL is a T-cell receptor alpha/beta +, CD3+, and CD7+ leukemia cell line, derived from a patient with refractory disease and early death. Injection of 5 x 10(7) MT-ALL cells i.v. caused disseminated human leukemia in hematopoietic and nonhematopoietic organs in 100% of SCID mice (n = 9) leading to death or terminal disease at 65 to 70 days after a uniform clinical course. To study possible therapeutic approaches for disseminated leukemia we utilized an immunotoxin, DA7, constructed by chemically linking the mouse IgG2b anti-CD7(3A1E) monoclonal antibody which recognizes a pan-T-cell marker expressed on almost all T-cell leukemias to deglycosylated ricin A-chain, a catalytic plant toxin and inhibitor of protein synthesis. Administration of DA7 led to greater than 5 log kill of clonogenic MT-ALL cells in vitro and selectively inhibited protein synthesis. DA7 was administered to mice at a dose of 10 micrograms/mouse/day for 5 consecutive days starting 8 days after i.v. inoculation of leukemia. The immunotoxin therapy resulted in significant long term survival over 348 days compared to untreated or control mice treated with anti-CD7 antibody and deglycosylated ricin A-chain which were all dead by day 70 (P less than 0.001). Even after more than 11 months there was no evidence of disease in 82% of the DA7 treated animals. SCID mice given i.p. injections (n = 9) developed an i.p. tumor mass but demonstrated metastasis outside the peritoneum with disseminated leukemia in hematopoietic and nonhematopoietic organs, a finding different from most conventional nude mouse models. The leukemia was fatal in 100% and killed the animals at 68-95 days. SCID mice given i.p. injections of MT-ALL completely responded to therapy with DA7, resulting in survival of 100% of the animals (n = 10) at 216 days (P less than 0.001 compared to untreated animals). Anti-CD7 antibody, deglycosylated ricin A-chain, and a control anti-melanoma immunotoxin (IND1-RTA) showed no therapeutic effect. We conclude that DA7 is an effective in vivo therapeutic agent against human MT-ALL in the SCID mouse system, suggesting potential usefulness for therapy of humans with poor prognosis T-cell leukemia.

[Etiopathogenesis and therapeutic trends in adult T-cell leukemia associated with HTLV-I retrovirus]

HTLV-I (Human T-cell leukemia virus type I) has been the first human retrovirus identified and then associated with a definite pathological entity, a leukemic syndrome that specifically affects mature T-lymphocytes (ATL, adult T-cell leukemia), expressing CD3+, CD4+, CD8-, CD11- phenotype. This form of leukemia/lymphoma is endemic in southwestern islands of Japan, although at present the number of HTLV-I seropositive individuals has greatly increased, with a worldwide diffusion, following the expansion wave of the AIDS-associated HIV retrovirus. In fact, double seropositivity for both HIV and HTLV is frequently found among intravenous drug users. Although ATL leukemia or lymphoma occurs with a low frequency among HTLV-I seropositive individuals, it is likely that the evolution from a latent phase of infection to acute leukemia could be favoured by depression of immunosurveillance levels in the host. Therefore, special attention is required to prevent the diffusion of this retrovirus in adults, taking into consideration that newborn babies from seropositive mothers have to be considered at high risk for development of HTLV-I associated disease, on the basis of their immature immunocompetence.

The multichain interleukin-2 receptor: a target for immunotherapy

Activation of resting T-lymphocytes induces synthesis of interleukin-2 (IL-2) and expression of cell surface receptors for this lymphokine. In contrast to resting normal T-cells that do not express high-affinity IL-2 receptors (IL-2R), abnormal T-cells of patients with leukemia-lymphoma, certain autoimmune disorders, and individuals rejecting allografts express this receptor. Exploiting this difference in receptor expression, antibodies to the IL-2 receptor have been used effectively to treat patients with leukemia and lymphoma. One approach is to use monoclonal antibodies produced in mice; the disadvantage is that they are highly immunogenic. In an effort to reduce the immunogenicity of the mouse monoclonal antibodies, monoclonal-antibody-mediated therapy has been revolutionized by generating humanized antibodies produced by genetic engineering in which the molecule is human except for the antigen-combining regions, which are retained from the mouse. Further, to increase its cytotoxic effectiveness, the monoclonal antibody has been armed with toxins or radionuclides. Alternatively, IL-2 itself has been linked to a toxin to kill IL-2 receptor-bearing cells. Thus, IL-2 receptor-directed therapy provides a new method for treating certain neoplastic diseases and autoimmune disorders and for preventing allograft rejection.