Development of a prognostic model for grading chronic graft-versus-host disease

The disease-specific survival (DSS) of 151 patients with chronic graft-versus-host disease (cGVHD) was studied in an attempt to stratify patients into risk groups and to form a basis for a new grading of cGVHD. The data included the outcome and 23 variables at the diagnosis of cGVHD and at the primary treatment failure (PTF). Eighty-nine patients (58%) failed primary therapy for cGVHD. Nonrelapse mortality was 44% after a median follow-up of 7.8 years. The probability of DSS at 10 years after diagnosis of cGVHD (DSS1) and after PTF (DSS2) was 51% (95% confidence interval [CI] = 39%, 60%) and 38% (95% CI = 28%, 49%), respectively. According to multivariate analysis, extensive skin involvement (ESI) more than 50% of body surface area; hazard ratio (HR) of 7.0 (95% CI = 3.6-13.4), thrombocytopenia (TP) (< 100 000/microL; HR, 3.6; 95% CI = 1.9-6.8), and progressive-type onset (PTO) (HR, 1.7; 95% CI = 0.9-3.0) significantly influenced DSS1. These 3 factors and Karnofsky Performance Score of less than 50% at PTF were significant predictors for DSS2. The DSS1 at 10 years for patients with prognostic factor score (PFS) at diagnosis of 0 (none), 1.9 and below [corrected] (ESI only or TP and/or PTO), above 1.9 and not above 3.5 [corrected] (ESI plus either TP or PTO), and more than 3.5 (all 3 factors) was 82%, 68%, 34%, and 3% (P =.05, <.001, <.001), respectively. The DSS2 at 5 years for patients with PFS at PTF of 0, 2 or less, 2 to 3.5, and more than 3.5 were 91%, 71%, 22%, and 4% (P =.2,.005, and <.001), respectively. It was concluded that these prognostic models might be useful in grouping the patients with similar outcome.     

Anti-B4-blocked ricin synergizes with doxorubicin and etoposide on multidrug-resistant and drug-sensitive tumors

Anti-B4-blocked ricin (anti-B4-bR) is an immunotoxin directed against CD19-positive cells that is currently being tested in several B-cell leukemia/lymphoma clinical trials. To explore the possibility of using anti-B4-bR in combination with chemotherapy protocols, we investigated the in vitro and in vivo cytotoxic effects of combining it with doxorubicin or etoposide using the lymphoma cell line Namalwa and a P- glycoprotein-expressing cell line, Namalwa/mdr-1, obtained by retroviral infection of Namalwa cells with the mdr-1 gene. Namalwa/mdr- 1 cells were slightly more sensitive to anti-B4-bR than Namalwa cells; IC37 values were approximately 4 pmol/L and 8 pmol/L, respectively. When anti-B4-bR was combined simultaneously with doxorubicin or etoposide, additive to supra-additive killing of Namalwa and Namalwa/mdr-1 cells was observed. In xenografts of Na-malwa/mdr-1 cells in severe combined immunodeficiency (SCID) mice, doxorubicin and etoposide at their maximum tolerated doses (3 mg/kg x 3 or 15 mg/kg x 3) showed no therapeutic effect. However, treatment with 5 daily bolus injections of anti-B4-bR (50 micrograms/kg) followed by treatment with doxorubicin or etoposide significantly increased the life span of the mice by 129% and 115%, respectively. After treatment with anti-B4-bR, the Namalwa/mdr-1 population expressed lower levels of P-glycoprotein, and this decrease may account for the synergistic action of the drug combinations. These results suggest that anti-B4-bR could be used to good effect in combination with current treatment regimens and further hint at a promising role for this immunotoxin in treatment of disease at the minimal residual disease stage, where cells may be resistant to chemotherapy.     

Graft failure after T-cell-depleted human leukocyte antigen identical marrow transplants for leukemia: II. In vitro analyses of host effector mechanisms

To identify mechanisms potentially contributing to graft failure, 19 leukemic recipients of T-cell-depleted marrow transplants who failed to engraft following a transplant of HLA identical sibling marrow depleted of T cells by soybean agglutinin (SBA) and sheep erythrocytes (E) were evaluated. Peripheral blood mononuclear cells isolated at the time of failure were consistently of host origin, bearing the phenotype of suppressor T cells (CD3+, CD8+, Leu 7+). A direct cytolytic effect on 51Cr-labeled donor-derived target cells was not detected, a finding that contrasts with the donor-specific cytotoxic host T lymphocytes that have been regularly observed in patients rejecting HLA nonidentical SBA -E- BMTs. However, these host T cells did exhibit a strong and specific suppressive activity against the donor marrow CFU- GM in vitro. Furthermore, in contrast to prior findings in durably engrafted recipients of SBA -E- BMTs, the lymphocytes isolated prior to or at the time of graft failure lacked natural killer surface antigen expression and effector function.     

Identification of a restriction fragment length polymorphism involving the oncogene ETS-1 on chromosome 11q23

Twenty four samples of DNA from 23 unrelated individuals were analyzed for the presence of a novel restriction fragment length polymorphism (RFLP) involving the proto-oncogene ETS-1 at an Xba I site. Four samples from unrelated individuals lacked an Xba I site, giving rise to a longer restriction fragment detectable by Southern analysis; two samples were from normal tissue, and two were from acute myelogenous leukemic blasts. Thus, no association could be found between the RFLP and disease among the individuals studied. Pedigree analysis of another cohort demonstrated Mendelian inheritance consistent with a somatic polymorphism. The practical applications of RFLP analysis in clinical and research settings, and the usefulness of this Xba I RFLP in the study of hematologic malignancies because of its location in 11q23, are discussed.     

Kinetics of intravenously administered heparin in normal humans

Heparin of five commercially available brands was used to study the disappearance of heparin anticoagulant activity in normal humans. The drug was administered intravenously by bolus injection and by continuous infusion. Heparin anticoagulant activity was determined by two assays: a diluted activated partial thromboplastin time (APTT) and an assay based on inactivation of bovine factor Xa, using a clotting system. After a bolus injection, the data fitted neither single exponential nor zero-order clearance. In semilogarithmic plots, heparin anticoagulant activity disappeared according to a slightly convex curve almost always preceded by a rapid initial loss of heparin anticoagulant activity. This disappearance profile was observed with all heparin regardless of the brand or assay system. Heparin anticoagulant activity estimated by the APTT disappeared faster than heparin anticoagulant activity estimated by the anti-Xa activity in the first phase. As expected, higher anticoagulant levels with the anti-Xa assay than with the APTT were also found on continuous infusion in normals as well as in patients treated for deep vein thrombosis or pulmonary embolism. The experimental data suggested a model based on the combination of a saturable and a linear clearance mechanism. These experimental data provide reliable guidelines for adjustment of the dose of heparin in single patients.     

Prolonged subcutaneous administration of recombinant alpha 2b interferon in patients with previously untreated Philadelphia chromosome-positive chronic-phase chronic myelogenous leukemia: effect on remission duration and survival: Cancer and Leukemia Group B study 8583 [see comments]

We investigated whether recombinant alpha 2b interferon (r alpha 2bIFN) would reduce the proportion of bone marrow Philadelphia chromosome (Ph) cells in chronic-phase chronic myelogenous leukemia (CML) by treating 107 previously untreated patients daily with r alpha 2bIFN at 5 x 10(6)IU/m2 subcutaneously. Patients with complete remission, partial remission, or partial hematologic remission received treatment until progression; those with progressive disease were taken off study and observed for survival. Sixty-three (59%) of the patients achieved at least a partial hematologic remission (24 complete remissions and 39 partial remissions). The median time to response for the 63 responders was 3.4 months, with a median duration of remission of 52 months and with 81% of responders continuing in remission beyond 12 months. The median survival for the 107 patients was 66 months. Of 78 patients with cytogenetic follow-up data, 31 (40%) achieved a partial cytogenetic response (n = 17) or a complete cytogenetic response (n = 14). The percentage of cytogenetic responders among all patients was 29% (31 of 107 patients). The median time to first cytogenetic response was 9 months. A major dose reduction of r alpha 2bIFN (> or = 50%) was required at some time during treatment in 38% of patients, 26% required 10% to 49% dose reductions, and 36% had minor dose reductions of < or = 10%. No association was observed between dose received and the attainment of a cytogenetic response. None of the usual prognostic factors (sex, race, performance status, weight loss, time from diagnosis to treatment, hepatosplenomegaly, age, symptoms, hemoglobin, or platelet, blast, basophil, or white blood cell count) were significantly related to survival. These data provide confirmation that major cytogenetic responses to prolonged administration of subcutaneous r alpha 2bIFN occur in 20% to 38% (95% confidence interval) of chronic- phase Ph-positive patients. Although it is hypothesized that patients achieving major cytogenetic responses to r alpha 2bIFN should have prolonged remission duration and survival compared with nonresponders, analyses of the effect of cytogenetic responders by both "landmark" and time-dependent covariate techniques fail to provide statistically significant evidence for an effect of cytogenetic response on remission duration or survival. This may be due in part to an effect size insufficiently large to be detected with the number of patients treated in this study. Thus, confirmation of remission duration or survival benefit, if any, of r alpha 2bIFN therapy in Ph-positive chronic-phase CML must await the outcome of randomized trials comparing IFN with conventional agents.     

An arginine to cysteine amino acid substitution at a critical thrombin cleavage site in a dysfunctional factor VIII molecule

We have analyzed the factor VIII (FVIII) protein and the nucleotide sequence around two thrombin cleavage sites, at arginine 372 in the FVIII heavy chain and arginine 1689 in the FVIII light chain in a naturally occurring dysfunctional FVIII variant, FVIII Okayama. The patient was a 42-year-old hemophiliac with a FVIII coagulant activity of 0.03 U/mL and a FVIII antigen level of 0.8 U/mL. The patient's FVIII was not thrombin activatable to levels seen in normal plasma. Immunoblotting of partially purified FVIII Okayama and normal FVIII showed that thrombin cleavage of the 92 kilodalton (Kd) heavy chain was impaired in the mutant protein. The patient's genomic DNA was amplified using the polymerase chain reaction with two sets of synthetic oligonucleotide primers spanning amino acid residues 319 to 400 and 1630 to 1720. Sequence analysis of the amplified DNA fragments revealed a cytosine to thymine transition, converting an arginine to a cysteine codon at residue 372. No abnormality was found in the FVIII light chain region analyzed. The patient's hemophilic brother and carrier mother revealed the same mutation. We conclude that the pathogenesis of hemophilia A in this patient is probably due to an arginine to cysteine substitution at a thrombin cleavage site in the FVIII heavy chain.