H. G. Prentice

Cytogenetics adds independent prognostic information in adults with acute lymphoblastic leukaemia on MRC trial UKALL XA. MRC Adult Leukaemia Working Party.

Cytogenetic classification of 350 adults with acute lymphoblastic leukaemia on MRC UKALL XA trial showed the following statistically significant associations: t(9;22) (11%) increased with increasing age and leucocyte counts (WBC) and most had a C/pre‐B immunophenotype. t(4;11) (3%) was associated with higher WBCs, increasing age and null immunophenotype. Other abnormalities of 11q (abn11q) (4%) were associated with male sex and T‐cell ALL. High hyperdiploidy (7%) and abn9p (5%) decreased with increasing WBC. High hyperdiploid patients were younger and tended to have C/pre‐B ALL. Triploidy/tetraploidy (3%) decreased and pseudodiploidy (11%) increased with increasing WBC. Cytogenetic classification was prognostically important (chi‐square for heterogeneity of classification = 53.36; P < 0.0001) and added significance to age, sex and WBC. A poor prognosis for patients classed as t(9;22) (13% disease‐free survival at 3 years), as t(4;11) 24% at 3 years) and hypodiploid (11% at 3 years), and good prognosis for abn12p (4% of subjects) and high hyperdiploidy (74% and 59% at 3 years respectively) were statistically significant, but the 54% 3‐year disease‐free survival for patients with t(1;19) was not. The prognosis of patients classed as t(9;22) was independent of other single variables. Abn12p, abnormalities of 11q (including t(4;11) cases) and hypodiploidy added prognostic significance to all other variables combined.

USE OF ANTI-T-CELL MONOCLONAL ANTIBODY OKT3 TO PREVENT ACUTE GRAFT-VERSUS-HOST DISEASE IN ALLOGENEIC BONE-MARROW TRANSPLANTATION FOR ACUTE LEUKAEMIA

Seventeen patients who received allogeneic bone-marrow transplants from matched or slightly mismatched (in four patients) siblings were observed for at least 60 days or until acute graft-versus-host disease (GvHD) developed. All donor marrows after preliminary manipulation were incubated with 1 mg of the murine monoclonal antibody OKT3 before infusion in an attempt to deplete them of immunocompetent T lymphocytes (opsonisation). In three of the seventeen patients acute GvHD of grade II or greater developed. Two of these patients died, but they had disseminated cytomegalovirus infection as well as GvHD. Eleven patients showed no evidence of acute GvHD, and four had transient limited skin rashes (grade I GvHD). Opsonisation of T lymphocytes has reduced the incidence of severe acute GvHD in this unit from 79% in an earlier group of 14 patients to 18% when added to prophylactic methotrexate.

Defibrotide for the treatment of hepatic veno-occlusive disease: results of the European compassionate-use study

Severe hepatic veno‐occlusive disease (VOD) is a recognized complication of autologous and allogeneic stem cell transplantation (SCT) that is often fatal. Defibrotide (DF) is a polydeoxyribonucleotide that has been found to have anti‐thrombotic, anti‐ischaemic and thrombolytic properties without causing significant anticoagulation. Preliminary studies have demonstrated activity for DF in the treatment of VOD, with minimal associated toxicity. In the present study, 40 patients who fulfilled established criteria for VOD were treated with DF on compassionate grounds in 19 European centres; 28 patients met risk criteria predicting progression of VOD and fatality or had evidence of multiorgan failure (MOF), and were defined as ‘poor‐risk’. DF was commenced intravenously at a median of 14 d (range, −2 d to 53 d) post SCT at doses ranging from 10 to 40 mg/kg. The median duration of therapy was 18 d (range, 2–71 d). Twenty‐two patients showed a complete response (CR) (bilirubin < 34·2 μmol/l and resolution of signs/symptoms of VOD and end‐organ dysfunction) [CR = 55%, confidence interval (CI) 40–70%] and 17 patients (43%) are alive beyond d +100. Ten poor‐risk patients showed a complete response (CR = 36%, CI 21–51%). These results demonstrate that DF is an active treatment for VOD following SCT and a randomized trial is now underway in order to further evaluate its role.

Graft rejection following HLA matched T-lymphocyte depleted bone marrow transplantation

Summary. Bone marrow graft rejection following HLA‐matched bone marrow transplantation (BMT) for leukaemia has been a rare problem. However, with the introduction of T‐lymphocyte depleted BMT, graft rejection is recognized as a new complication. At the Royal Free Hospital (RFH) in London T‐depletion is achieved using two monoclonal antibodies with complement mediated lysis. The methodology was extended to other centres and in total 56 patients have received T‐depleted, HLA matched BMT. Twelve of 56 patients have had graft rejection. At the RFH three of 41 (7%) patients have had rejection whereas at collaborating centres nine of 15 (60%) patients have had rejection. We have investigated these rejections in order to identify factor(s) responsible. Rejection was not restricted by patient or donor characteristics, nor disease status. Patient management, chemotherapy conditioning, efficiency of T‐depletion, graft versus host disease (GvHD), and infection post BMT, were not consistently implicated. The major difference between the RFH and all other centres was in the radiotherapy (RT) conditioning: The RFH prescribed a single fraction of 7‐5 Gy total body irradiation (TBI) whilst collaborating centres gave 10 or 12 Gy fractionated TBI. We conclude that the different incidence of rejection (7% v. 60%) relates primarily to the RT conditioning although the mechanisms(s) of rejection remain unknown. We conclude that where T‐depleted BMT is used, compensation by more intensive RT conditioning is required in order to avert graft rejection.

Toxoplasmosis in bone marrow transplantation: a report of two cases and systematic review of the literature

Toxoplasma infection represents a rare but often fatal complication in bone marrow transplant (BMT) recipients. We report two cases of toxoplasmosis: one of successfully treated cerebral toxoplasmosis after peripheral blood stem cell transplantation, and a fatal case of pulmonary toxoplasmosis in a BMT recipient. We have systematically reviewed the 110 published cases of toxoplasmosis following BMT. We analyzed the pre-transplant and clinical features of BMT recipients developing toxoplasmosis, together with the diagnostic procedures used and treatment given. By univariate and multivariate statistical analysis we analyzed the risk factors for diagnosis (during life vs post-mortem) and Toxoplasma-related mortality. Ante-mortem diagnosis was made in 47% of cases. Site of infection (P = 0.02; odds ratio 10.8), presence of symptoms at onset (P = 0.01) and conditioning regimen (P = 0.04) were factors influencing whether the diagnosis was made before or after death. Overall mortality rate was 80% and that attributed to toxoplasmosis was 66%. Variables influencing outcome were: site of infection (P = 0.02; odds ratio 5.28), day of onset (P = 0.04) and conditioning regimen (P = 0.04). Underlying disease (P = 0.02; odds ratio 9.45), among patients diagnosed before death, was the most significant factor influencing outcome.

Terminal Transferase Enzyme Assay and Immunological Membrane Markers in the Diagnosis of Leukaemia: a Multiparameter Analysis of 300 Cases

Multiparameter analyses have been carried out with recently developed enzyme and membrane markers in 300 patients with various leukaemias including ALL, AML, but excluding Ph1 positive leukaemias.

TRANSFER OF A FUNCTIONING HUMORAL IMMUNE SYSTEM IN TRANSPLANTATION OF T-LYMPHOCYTE-DEPLETED BONE MARROW

To test the effect of transplantation of T-cell-depleted bone marrow on recipient immune function the results of pre-transplantation immunisation with tetanus toxoid and hepatitis-B vaccine were studied in 38 donor-recipient pairs. Immunisation of the donor alone resulted in transfer of an antibody response to the recipient; immunisation of both donor and recipient resulted in potentiation of the antibody response in both magnitude and duration. These findings indicate that donor T-cell-depleted marrow can transfer humoral immunity to the recipient and that appropriate pre-transplant immunisation schedules may be of benefit to the recipient.

A technique for rapid isolation of bone marrow mononuclear cells using Ficoll-Metrizoate and the IBM 2991 blood cell processor

Marrow from seven normal donors and patients has been layered onto Ficoll‐Metrizoate (FM) under pressure in the IBM 2991 blood cell processor to isolate the mononuclear cell (MNC) population prior to allogeneic transplantation or cryopreservation. This separation method, which takes less than 90 min, is a further development since our previous report detailing the use of the IBM 2991 to produce a concentrated marrow‘buffy coat’for infusion (Gilmore & Prentice, 1981). By adding FM to the system, marrow stem cells are further concentrated in a small volume with removal of unwanted granulocytes and red blood cells. This facilitates the in vitro treatment of marrow with monoclonal antibodies (Granger et al, 1982) or drugs, for either the selective elimination of malignant cells prior to autologous bone marrow transplantation (BMT), or T lymphocytes in an attempt to prevent graft versus host disease (GvHD) in allogeneic BMT.

Long-term survival in allogeneic bone marrow transplant recipients following acyclovir prophylaxis for CMV infection

Recipients of HLA-matched, related or unrelated allogeneic BMT who were CMV seropositive or those receiving unmanipulated marrow from a seropositive donor were randomised to receive one of three treatment regimens, i.v. acyclovir 500 mg/m2 three times a day from 5 days before transplant to 30 days after transplant followed by oral acyclovir 800 mg four times a day for a further 6 months, i.v. acyclovir followed by placebo, or 400 mg oral acyclovir four times a day followed by placebo (control). This paper reports the 1 year data on the same cohort of patients which was previously reported. Intravenous acyclovir (IV/PCB) significantly reduced the risk of CMV infection when compared to the control group. The frequency of adverse events reported was comparable among the three groups. The mortality rate was significantly reduced by the sequential use of i.v. acyclovir followed by oral acyclovir, resulting in a 19% survival advantage at 1 year from transplant.

Immunological monitoring of residual disease in treated thymic acute lymphoblastic leukaemia

Abstract Combinations of antisera to human differentiation-linked antigens were used in an indirect immunofluorescence system to identify residual leukaemic blast cells in bone marrow samples from 18 patients treated for the thymic variant of acute lymphoblastic leukaemia (Thy-ALL). In six patients, 0.5 to 5.0% of nucleated cells in marrow samples taken during apparent disease remission were found to have an antigenic phenotype not normally demonstrable on bone marrow cells. These cells contained terminal transferase enzyme, expressed surface human T lymphoid antigens (and in some cases cortical thymocyte antigen) but lacked Ia-like antigens. This phenotype was characteristic of Thy-ALL blasts at the time of diagnosis and at relapse indicating that these minor subpopulations were leukaemic. In the remaining 12 cases, no cells of abnormal phenotype were detected, although some of these patients later relapsed with cells of typical Thy-ALL phenotype. The above findings indicate that Thy-ALL cells may be identified during bone marrow remission by virtue of their expression of a unique combination of differentiation antigens in an anatomically inappropriate site, and that this technique is more sensitive than conventional morphological analysis. The observations also provide information about shifts of membrane marker expression in Thy-ALL.