Sequential analysis of 43 patients with non-Hodgkin's lymphoma: clinical correlations with cytogenetic, histologic, immunophenotyping, and molecular studies

Few reports correlating specific cytogenetic abnormalities with distinct subtypes of lymphoma have performed serial studies at diagnosis and at tumor recurrence or progression. In our file of 325 cytogenetically analyzed non-Hodgkin's lymphoma (NHL) patients studied over the past decade, 43 had serial biopsies, 39 of whom had at least two successful preparations; of the 43, nine had one and 32 had two or more cytogenetically abnormal specimens. In this study, we correlated cytogenetic, histopathologic, molecular, and clinical parameters. Patients with low-grade lymphomas were as likely as patients with intermediate- or high-grade lymphomas to acquire new chromosomal abnormalities with time (16 of 23 patients as compared with 7 of 16; P2 = .11, chi 2 test). In four patients, originally diagnosed indolent disease progressed to aggressive disease; all had t(14;18), all gained additional chromosomal abnormalities with disease progression, and three of the four expressed abnormalities associated with disease progression and/or short survival: der(18), +7, and/or +12. Cytogenetic results from early disease were compared with those obtained later in disease: in the t(14;18) group, the most common abnormalities were +7 (eight patients) and der(18) (five patients), both seen later in disease. The most common abnormalities in patients without t(14;18) were 6q deletions; they were seen in both early and late disease and were associated with significantly shorter survivals (P2 = .0014) compared with all patients without 6q deletions. Secondary chromosomal abnormalities, observed after at least one previous abnormal study, were seen in 19 of 22 t(14;18) patients and in 11 of 21 patients without t(14;18) and were associated with a poor survival (P2 = .13) compared with patients without any secondary chromosomal abnormalities. Chromosome 1 abnormalities were seen in almost half of the patients and were observed in initial specimens and early in disease as well as late in disease and as secondary abnormalities; 1q involvement was more frequent than 1p (15 versus eight patients) and was significantly associated with poor survival only in patients with intermediate-/high- grade disease; the most common breakpoints were 1q21-q22 (nine patients) and 1p36 (six patients). Breakpoints at 2q21 and 3q27-q29 were limited to patients with t(14;18) and were almost exclusively secondary in nature. Molecular studies in 24 of our patients showed discrepancies with the cytogenetic results in only three patients: two had t(14;18) but no molecular rearrangements while two patients had no visible t(14;18) but were positive for major breakpoint region (MBR) rearrangement. The presence of MBR or minor breakpoint cluster (MCR) rearrangement had no apparent effect on survival.(ABSTRACT TRUNCATED AT 400 WORDS)     

9-cis retinoic acid induces complete remission but does not reverse clinically acquired retinoid resistance in acute promyelocytic leukemia

9-cis retinoic acid (RA) is a high-affinity ligand for both retinoic acid receptors (RARs) and retinoid "X" receptors (RXRs). Although all- trans RA does not bind to RXRs, RAR/RXR heterodimers or RXR/RXR homodimers bind to specific DNA response elements and modulate proliferation and differentiation of normal and malignant cells. Because the development of clinical resistance to all-trans RA has been associated with a progressive decrease in plasma drug concentrations, we evaluated the ability of 9-cis RA to induce in vitro cytodifferentiation in subclones of a retinoid-sensitive and resistant APL cell line (NB4) and in short-term cultures of fresh leukemic cells aspirated from patients. We also evaluated the clinical activity and pharmacokinetics of 9-cis RA (LGD 1057) in patients with APL who were previously treated with all-trans RA. In vitro tests of both retinoid- sensitive NB4 cells, as well as samples of fresh cells from 11 patients with APL, showed relatively equivalent degrees of sensitivity to both 9- cis RA and all-trans RA at concentrations ranging from 10(-6) to 10(-8) mol/L; however, no substantial cytodifferentiation was observed using either drug alone or in combination (10(-6) mol/L of each) in retinoid- resistant NB4 cells. Seven patients with APL who had previously relapsed from a remission induced by all-trans RA were treated with 9- cis RA at daily oral doses ranging from 30 to 230 mg/m2. Pharmacokinetic studies showed that the mean terminal plasma half-life of 9-cis RA (1.3 hours) changed very little after several weeks of dosing, although the mean change per dose level in area under the plasma concentration x time curves and peak plasma concentrations showed a decrease by 49% and 45%, respectively. Peak plasma concentrations equaled or exceeded concentrations that were effective against retinoid-sensitive cells in vitro. Despite these favorable pharmacokinetic results, only one of the seven patients achieved complete remission, corroborating in vitro studies of blasts from three of the nonresponders that showed a relatively equivalent degree of resistance to both retinoids. Our results suggest that while 9-cis RA may not induce its own catabolism to the same degree as all-trans RA, this feature does not appear to overcome clinically acquired resistance to all-trans RA in APL. Nonetheless, the drug can induce complete remissions in patients with APL and may be useful for extended therapy in other diseases. Future studies should address the use of lower doses in patients who have not previously received retinoid therapy.(ABSTRACT TRUNCATED AT 400 WORDS)     

Platelets inhibit fibrinolysis in vitro by both plasminogen activator inhibitor-1-dependent and -independent mechanisms

Platelet-rich thrombi are resistant to lysis by tissue-type plasminogen activator (t-PA). Although platelet alpha-granules contain plasminogen activator inhibitor-1 (PAI-1), a fast-acting inhibitor of t-PA, the contribution of PAI-1 to the antifibrinolytic effect of platelets has remained a subject of controversy. We recently reported a patient with a homozygous mutation within the PAI-1 gene that results in complete loss of PAI-1 expression. Platelets from this individual constitute a unique reagent with which to probe the role of platelet PAI-1 in the regulation of fibrinolysis. The effects of PAI-1-deficient platelets were compared with those of normal platelets in an in vitro clot lysis assay. Although the incorporation of PAI-1-deficient platelets into clots resulted in a moderate inhibition of t-PA-mediated fibrinolysis, normal platelets markedly inhibited clot lysis under the same conditions. However, no difference between PAI-1-deficient platelets and platelets with normal PAI-1 content was observed when streptokinase or a PAI-1-resistant t-PA mutant were used to initiate fibrinolysis. In addition, PAI-1-resistant t-PA was significantly more efficient in lysing clots containing normal platelets than wild-type t-PA. We conclude that platelets inhibit t-PA-mediated fibrinolysis by both PAI- 1-dependent and PAI-1-independent mechanisms. These results have important implications for the role of PAI-1 in the resistance of platelet-rich thrombi to lysis in vivo.     

Epidemiologic background of blood donors with antibody to human T-cell lymphotropic virus. Transfusion Safety Study Group

We interviewed 51 blood donors in four major US metropolitan areas subsequently found to have had antibodies to human T-cell lymphotropic virus (anti-HTLV) in late 1984-early 1985. Sixteen donors (31%) reported that they or a sexual contact had a history of blood transfusion. Twelve donors (24%) reported that they or a sexual contact used intravenous drugs. Ten donors (20%) were blacks born in the southeastern US. Four of the male donors (15%) reported homosexual contact. The most common characteristic was an association with Japan or the Caribbean basin (61%). These results show a broader variation of epidemiologic backgrounds than anticipated.