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Gain-of-function (GOF) mutations of Janus kinase 2 (JAK2) are frequently seen in myeloproliferative disorders (MPDs). Meanwhile, JAK3 activating substitutions have been found in a few megakaryocytic cell lines and in primary myeloid leukemia (AMKL). Here, we sought to discover novel leukemogenetic mutations in de novo acute myeloid leukemia of non-Down syndrome (N-DS) by DNA sequencing. A total of 191 normal Caucasian individuals were studied to define single nucleotide polymorphisms (SNPs) within the JH2 and JH6 domains. Although known activating substitutions were observed in rare cases of acute myeloid leukemia (AML) (V722I [2/134] or P132T [1/119]), all samples were wild-type (WT) for the oncogenic A572V (119/119). Interestingly, a novel homozygous mutation (P132A) was discovered in a patient with acute megakaryoblastic leukemia and in vivo studies demonstrated that its ectopic expression was oncogenic in a mouse xenotransplant model. This study defines a novel JAK3 mutation among patients with N-DS AML and demonstrates that normal individuals can also display germline JAK3 substitutions, previously proven to have oncogenic properties, in vitro and in vivo. The discovery of these substitutions in normal donors encourages future studies to define new risk factors among patients with MPDs.

All-trans-retinoic acid (ATRA) has greatly modified the prognosis of acute promyelocytic leukemia; however, the role of maintenance in patients in molecular complete remission after consolidation treatment is still debated. From July 1993 to May 2000, 807 genetically proven newly diagnosed acute promyelocytic leukemia patients received ATRA plus idarubicin as induction, followed by 3 intensive consolidation courses. Thereafter, patients reverse-transcribed polymerase chain reaction-negative for the PML-RARA fusion gene were randomized into 4 arms: oral 6-mercaptopurine and intramuscular methotrexate (arm 1); ATRA alone (arm 2); 3 months of arm1 alternating to 15 days of arm 2 (arm 3); and no further therapy (arm 4). Starting from February 1997, randomization was limited to ATRA-containing arms only (arms 2 and 3). Complete remission was achieved in 761 of 807 (94.3%) patients, and 681 completed the consolidation program. Of these, 664 (97.5%) were evaluated for the PML-RARA fusion gene, and 586 of 646 (90.7%) who tested reverse-transcribed polymerase chain reaction-negative were randomized to maintenance. The event-free survival estimate at 12 years was 68.9% (95% confidence interval, 66.4%-71.4%), and no differences in disease-free survival at 12 years were observed among the maintenance arms.

Purpose: To compare the antitumor efficacy of three different anthracyclines in combination with cytarabine and etoposide in adult patients with newly diagnosed acute myeloid leukemia (AML)., Patients and Methods: We randomly assigned 2,157 patients (age range, 15 to 60 years) to receive intensive induction-consolidation chemotherapy containing either daunorubicin, idarubicin, or mitoxantrone. After achieving complete remission (CR), patients were assigned to undergo either allogeneic or autologous stem-cell transplantation (SCT), depending on the availability of a sibling donor., Results: The overall CR rate (69%) was similar in the three groups. Autologous SCT was performed in 37% of cases in the daunorubicin arm versus only 29% and 31% in mitoxantrone and idarubicin, respectively (P < .001). However, the disease-free survival (DFS) and survival from CR were significantly shorter in the daunorubicin arm: the 5-year DFS was 29% versus 37% and 37% in mitoxantrone and idarubicin, respectively. The proportion of patients who underwent allogeneic SCT (22%) was equivalent in the three treatment groups, and the outcome was similar as well. The [corrected] 5-year overall survival rates were 31%, 34%, and 34%, [corrected] respectively., Conclusion: In adult patients with AML who do not receive an allogeneic SCT, the use of mitoxantrone or idarubicin instead of daunorubicin enhances the long-term efficacy of chemotherapy.

Etanercept is a recombinant human soluble tumor necrosis factor (TNF-alpha) receptor fusion protein that inhibits TNF-alpha, a major mediator in the pathogenesis of graft-versus-host disease (GVHD). The purpose of our study was to evaluate the safety and efficacy of etanercept therapy in 21 patients with steroid-refractory acute GVHD (aGVHD) (n = 13) and chronic GVHD (cGVHD) (n = 8). Etanercept 25 mg was given subcutaneously twice weekly for 4 weeks followed by 25 mg weekly for 4 weeks. At the time of initiation of etanercept, 14 patients had skin, 13 had gastro-intestinal, 5 had liver, 5 had pulmonary, and 4 had oral involvement. Twelve patients (57%) completed 12 doses of therapy. Overall, 11 of 21 patients (52%) responded to the treatment with etanercept, including 6 patients (46%) with aGVHD [n = 4 complete response (CR), n = 2 partial response (PR)] and 5 patients (62%) with cGVHD (n = 1 CR, n = 4 PR). Clinical responses were most commonly seen in patients with refractory gut aGVHD with 55% of the patients having a CR and 9% having a PR. CMV reactivation occurred in 48% of patients, bacterial infections in 14% of patients, and fungal infections in 19% of patients. Fourteen patients (67%) were alive after a median follow-up of 429 days (range 71-1007 days) since initiation of etanercept. Seven patients died, 3 of infections, 2 of refractory aGVHD, and 2 of disease progression. In conclusion, our preliminary data indicate that etanercept is well tolerated and can induce a high response rate in patients with steroid-refractory aGVHD and cGVHD, particularly in the setting of GI involvement.

The Gruppo Italiano Malattie Ematologiche dell'Adulto (GIMEMA) 0496 protocol, through the central handling of bone marrow samples at presentation, allowed us to combine cytogenetic and molecular information on a large series of adults with acute lymphoblastic leukemia (ALL) treated homogeneously, enabling us to define as broadly as possible their genetic profile and to determine the impact on outcome of the cytogenetic-molecular signature. Of 414 patients centrally processed, 325 were considered for the categorization into the following cytogenetic-molecular subgroups: normal, t(9;22)/BCR-ABL, t(4;11)/MLL-AF4, t(1;19)/E2A-PBX1, 9p/p15-p16 deletions, 6q deletions, miscellaneous structural abnormalities, and hyperdiploid. The inclusion into each subgroup was based on a hierarchical approach: molecular abnormalities with adverse prognosis had precedence over karyotypic changes with less-defined prognosis and the latter over ploidy. Patients without abnormalities and those with isolated 9p/p15-p16 deletions showed a relatively favorable outcome (median disease-free survival [DFS], > 3 years). The t(9;22)/BCR-ABL, t(4;11)/MLL-AF4, t(1; 19)/E2A-PBX1 defined a group with dismal prognosis (median DFS, 7 months), whereas 6q deletions, miscellaneous aberrations, and hyperdiploidy predicted an intermediate prognosis (median DFS, 19 months). This study highlights the importance of a combined cytogenetic-molecular profiling of adult ALL at presentation as a critical independent determinant of their outcome, providing further evidence of the necessity of a risk-adapted therapeutic algorithm for an optimal management of these patients.

Background and Objectives: The prognosis of elderly patients with acute myelogenous leukemia (AML) is usually dismal, while the true survival of older patients not included in clinical trials is not known. We retrospectively evaluated the impact on survival of an aggressive versus a non-aggressive approach in 1005 patients aged >60 years registered in the database of the GIMEMA cooperative group., Design and Methods: Group A patients (n=621) received aggressive treatment, while group B patients (n=384) underwent non-aggressive therapy. The groups were different for risk factor distribution: the patients in group B had a higher median age, worse performance status (PS) and a higher proportion of previous myelodysplastic disease., Results: The overall median survival was 7 and 5 months in groups A and B, respectively (p min of 0.0001). At multivariate analysis the following factors were associated with a significantly shorter survival: age >71 years (RR=1.27; 95% CI=1.07-1.50), PS=2-4 (RR=1.44; 95% CI=1.24-1.68), white cell count > 10,000 mL (RR=1.37; 95% CI=1.06-1.75), and heart dysfunction requiring treatment (RR=1.26; 95% CI=1.05-1.50). No difference in survival was associated with aggressive or non-aggressive treatment (RR=1.1; 95% CI=0.94-1.32). Patients aged min of 70 years, with no heart disease, but a white cell count > 10,000/mL showed a significantly better survival when treated aggressively (median survival 7 vs 3 months, p = 0.011)., Interpretation and Conclusions: Despite an obvious selection of patients with a worse prognosis in group B, the difference in survival between the two groups was marginal. Multivariate analysis failed to demonstrate a significant survival benefit in aggressively treated patients. All these considerations indicate that elderly patients with AML are overall unlikely to benefit from aggressive treatment, so that this should be offered only to selected patients.

Background and Objectives: The outcome of adult patients with acute lymphoblastic leukemia (ALL) is discouraging, only about 30% of them becoming long-term survivors. A small fraction of patients are resistant to the first line treatment, while most patients relapse within two years of achieving complete remission (CR). No standard treatment exists for refractory or relapsed patients. The GIMEMA group designed a phase II trial for adult ALL patients with refractory or relapsed disease., Design and Methods: Patients aged >15 years with primary refractory or relapsed ALL were eligible for this study. The salvage strategy included a single high dose of idarubicin combined with high dose cytarabine, followed by consolidation therapy leading to a stem cell transplant procedure according to donor availability., Results: From 1998 to 2002, 135 patients were enrolled. Seventy-five patients (55%) achieved CR, including 12 Philadelphia-positive cases; 44 patients had persistent leukemia and 16 died during reinduction. Fifty patients received a stem cell transplant: 19 from an HL-A identical sibling, 16 from an unrelated donor, 7 from a haploidentical relative, 2 received cord blood, and 6 had an autotransplant. The median disease-free and overall survival were both short (5.0 and 6.4 months, respectively); however, after a median follow-up of 40 months, 13 patients are alive, 10 of whom are free of disease (9 transplanted), while 3 are alive with leukemia., Interpretation and Conclusions: The treatment induced CR in a high percentage of poor prognosis patients, thus rendering a transplant procedure feasible in most of them. However, significant rates of transplant-related mortality and post-transplant relapse encourage the search for more effective and less toxic conditioning regimens.

Background and Objectives: Front line treatment of acute promyelocytic leukemia (APL) with all-trans retinoic acid (ATRA) and chemotherapy (CHT) results in molecular remission in approximately 95% of patients tested after consolidation. The small fraction of patients with persistence of molecular disease (i.e. those in whom polymerase chain reaction (PCR) is positive for PML/RARalpha) after such therapy are thought to have a dismal prognosis but has not yet been investigated in detail., Design and Methods: We analyzed the clinico-biological features at presentation of APL patients who showed PCR-detectable residual disease and compared them to those of patients achieving molecular remission after AIDA induction and consolidation. Furthermore, we report the outcome of patients with molecularly persistent disease treated with salvage therapy., Results: Patients attaining molecular remission (n=650) and patients who tested PCR+ve at the end of consolidation (n=23) were not statistically significantly different as regards median age, white cell and platelet counts, morphologic subtype (M3 or M3v), fibrinogen levels or PML/RARalpha transcript type. As to treatment outcome after salvage therapy, 7 patients were treated before morphologic relapse [3 with chemotherapy and autologous stem cell transplantation (SCT) and 4 with allogeneic SCT], and are alive after 64-118 months. Of 16 patients treated at the time of morphologic relapse, only 2 patients are alive, both of whom received an allogeneic SCT., Interpretation and Conclusions: Our findings indicate that APL patients who are molecularly resistant to the AIDA protocol have no distinguishing features at presentation. Their outcome suggests the need for early therapeutic intervention with aggressive treatment prior to the occurrence of hematologic relapse.

We analyzed the clinicobiological features and treatment outcome of a series of acute promyelocytic leukemias (APLs) occurring as a second tumor (APL-st's, n = 51) and compared these with a large group of de novo APL cases (n = 641), both observed by the Italian cooperative group GIMEMA. In the APL-st group, 37 patients had received radiotherapy and/or chemotherapy for their primary malignancy (PM), while 14 had been treated by surgery alone. Compared with de novo APL patients, APL-st patients were characterized by a predominance of females (P <.003), higher median age (P <.05), and worse performance status (P <.005). The median time elapsed between PM and APL-st was 36 months, with a longer latency for patients treated with surgery alone. No significant differences were found with regard to karyotypic lesions or type of promyelocytic leukemia/retinoic acid receptor alpha (PML/RARalpha) fusion in the 2 cohorts. A high prevalence of PMs of the reproductive system was observed among the female APL-st population (24 [71%] of 34 patients in this group had suffered from breast, uterine, or ovarian cancer). Thirty-one APL-st and 641 de novo APL patients received homogeneous APL therapy according to the all-trans retinoic acid (ATRA) and idarubicin regimen (the AIDA regimen). The complete remission (CR), 4-year event-free survival (EFS), and 4-year overall survival (OS) rates were 97% and 93%, 65% and 68%, and 85% and 78% in the APL-st and de novo APL groups, respectively. In spite of important clinical differences (older age and poorer performance status), the APL-st group responded as well as the de novo APL group to upfront ATRA plus chemotherapy, probably reflecting genetic similarity.

We report two cases of acute myeloid leukemia (AML) French-American-British M4 classification with trisomy 8 at diagnosis as the sole chromosome abnormality. Both patients were treated with the GIMEMA AML-10 protocol and underwent autologous bone marrow transplantation (ABMT) in hematologic remission. Peripheral blood stem cells (PBSC), and bone marrow in one patient, were collected after consolidation therapy and tested by fluorescence in situ hybridization (FISH) analysis with an alpha-satellite probe for chromosome 8. It revealed that all samples were positive for minimal residual disease (MRD) as the value of trisomic cells exceeded the mean +3 standard deviations of the controls. ABMT was done following a myeloablative regimen (busulphan/cyclophosphamide) and PBSC were reinfused. Both patients relapsed, 4 and 2 months, respectively, after autotransplant. Although more data are needed, these results suggest that the persistence of MRD, as detected by FISH, in stem cell collections, is associated with a poor outcome in AML patients with trisomy 8 undergoing ABMT.

Background and Objective: Multiple myeloma (MM) typically afflicts elderly patients. High-dose therapy has recently been shown to lead to a better outcome than standard treatment, mainly in younger patients. The extent to which older subjects can benefit from intensified approaches without excessive toxicity is examined in this study., Design and Methods: Between December 1994 and May 1997, 12 Italian Multiple Myeloma Study Group institutions entered 68 patients at diagnosis (median age 65) into an intensified chemotherapy regimen: cyclophosphamide (CY) 3 g/m(2) plus melphalan 60 mg/m(2) followed by peripheral blood progenitor cells (PBPC) and G-CSF (CM regimen). CY (day 0) and G-CSF were used to mobilize PBPC harvested by a single leukapheresis on day 10. Melphalan was infused on day 11. PBPC were kept unprocessed at 4 degrees C for 48 hours and reinfused on day 12. Three CM regimens were delivered at 6-month intervals., Results: Sufficient PBPC to support the first CM cycle were available (median CD34(+) harvest: 4.9x10(6)/kg), but dropped significantly after the second (median CD34(+) harvest: 2x10(6)/kg) and the third (median CD34(+) harvest: 0.9x10(6)/kg). The median durations of severe neutropenia (absolute neutrophil count < 500 microL) were 3, 4, and 3 days, and those of severe thrombocytopenia (platelets < 25,000/microL) were 2.5, 2, and 1 days, after the first, second and third courses, respectively. The frequency of extramedullary toxicities was low. Treatment-related mortality (TRM) was 3% after the first CM, only. Complete remission (CR) was 14% after the first, 16% after the second and 27% after the third CM. After a median follow-up of 34 months (range 19-49 months), median event-free survival was 35.6 months., Interpretation and Conclusions: These results indicate that dose-intensity of melphalan can be increased by reinfusing PBPC with acceptable low toxicity. The combination of CY and melphalan followed by PBPC is an effective chemotherapy for elderly myeloma patients. Repeated melphalan infusion hampered subsequent CD34(+) harvests.

We investigated the histologic pattern and the cell proliferative activity of myeloma cells by the analysis of the nucleolar organizer regions (AgNORs) in bone marrow biopsy specimens from 150 multiple myelomas at diagnosis. The objective was an attempt to define risk groups of myeloma patients. On univariate analysis, the percentage of bone marrow plasma cells (BMPC%), the pattern of infiltration, the degree of plasma cell (PC) atypia, the marrow fibrosis, and the number of AgNOR/PC were correlated with survival time. On multivariate analysis, only AgNOR counts and pattern of infiltration retained independent prognostic significance. At 4-year followup, all patients with BMPC% < or = 20, interstitial pattern of invasion, and well-differentiated (G1) PC plus AgNOR/cell < or = 3.32 were alive, while no patient with BMPC% >50, diffuse pattern of infiltration, and poorly differentiated (G3) PC plus AgNOR/cell >5.15 survived (p < 0.0001). In conclusion, the histologic pattern and proliferative activity of myeloma cells, evaluated by AgNOR counts, are reliable predictors of survival in myeloma. Both parameters can be easily assessed in the same biopsy specimen, are reproducible, and permit identification of a group of patients with favourable outcome at 4-year followup. Thus, bone marrow biopsy should always be included in the diagnostic procedures for myeloma patients.

A retrospective analysis was performed on two subsequent myeloma patient series treated with the same conventional induction treatments, melphalan and prednisone or alternating VMCP/VBAP: 273 were enrolled in the multicentre M83 trial (M83 trial group) from 1983 to 1986; 160 were referred to a single institution (Haemat. To group) from 1986 to 1994. Response to treatment was very similar in the two groups (53% v 50.3%). Remission duration curves merely overlapped (median 20 v 21 months). However, overall survival was significantly longer in the Haemat. To group (43.2 v 33 months, P < 0.04). This difference was due to a prolonged period from relapse or progression to death (21 v 8 months, P < 0.01; 20.8 v 7 months, P < 0.009). Prolonged survival was also observed in poor-prognosis patients with a serum beta2-microglobulin level > 3 mg/l, in the Haemat. To group (31.8 v 24.2 months, P < 0.04). The same induction treatments produced almost identical response rate and remission duration in both groups, but overall survival was 10 months longer for one group. However, it could be argued that treatment salvage modalities and support therapies have been improved in a decade. Lastly, induction treatments did not influence overall survival.

The argyrophilic nucleolar organizer regions (AgNORs) were analysed in bone marrow biopsies from 80 patients with multiple myeloma (MM) at presentation. The mean AgNOR number per MM cell (AgNOR counts) and their distribution within the nucleus (configuration) were assessed. AgNOR counts were significantly associated with several recognized prognostic factors: Durie and Salmon clinical staging system (p = 0.02), percentage of plasma cells (PCs) in aspirates (p = 0.01) and in bone marrow biopsies (p = 0.0000), pattern of bone marrow involvement (p = 0.0003), calcaemia (p = 0.0005) and creatininaemia (p = 0.0003). AgNOR counts were also associated with the degree of PC differentiation (p = 0.0000). A single central cluster of 2-3 large-sized AgNORs (configuration A) was evident in most G1 MM; one cluster of 4-5 medium-sized dots or two clusters of 2-4 dots (configuration B) were seen in most G2 MM; many small-sized, scattered dots were present in G3 MM (configuration C). AgNOR counts and configuration were related to the prognosis: in the univariate analysis, the 5 year survival rate was 7% for cases with > 4.5 AgNORs/cell and 46% for cases with < or = 4.5 AgNORs/cell (p = 0.01), 53% for configuration A, 12% for configuration B and 0% for configuration C (p = 0.0000). AgNOR counts (p = 0.02) and configuration (p = 0.000) were independent prognostic variables in the multivariate analysis. The AgNOR counts were significantly higher in "fulminant myeloma" than in less aggressive cases (p = 0.002). The plasma cell labelling index (LI%), evaluated in 44 MM patients, showed significant correlation with prognosis: the 5 year survival rate was 51% for LI% < or = 1 and 17% for LI% > 1 (p = 0.02). More than 70% of patients with low LI% had low AgNOR counts and more than 70% of patients with high LI% had high AgNOR counts (p = 0.007). AgNOR counts and configuration reflect the myeloma cell mass, the degree of differentiation and the kinetics of the myeloma cells. They offer an exact evaluation of the tumour characteristics and can be useful additional parameters for MM prognosis.

Background: Low levels of serum albumin have been reported to be associated with a poor prognosis in lymphoproliferative disorders., Methods and Results: Clinical and laboratory data were retrospectively evaluated in a series of 342 patients with chronic lymphocytic leukemia (CLL). In univariate analysis, survival was significantly influenced (p less than 0.01) by traditional prognostic factors: number of lymphoid areas involved, volume of adenopathies, presence and degree of hepatomegaly and splenomegaly, anemia, thrombocytopenia, peripheral blood lymphocytosis (greater than 60 x 10(9)/l), percentage of bone marrow lymphocytes (greater than 50%). Among variables not included in the traditional staging systems, age over 70, hypoproteinemia (less than 6 gr/dl) and hypoalbuminemia (less than 3.5 gr/dl) adversely affected prognosis. All the most widely adopted staging systems recognize no more than three groups of patients with statistically different outcomes. In multivariate analysis, the prognostic value of serum albumin was independent of both age and the group of variables included in each staging system considered., Conclusions: We suggest that evaluation of the serum albumin level could be useful, in future multicenter studies, for further implementation of the staging of CLL.

An analysis of survival by response category was performed on 76 patients with stage II and III multiple myeloma, who were treated with oral melphalan and prednisone. The analysis demonstrated a survival advantage for responders over non-responders only in stage III patients (32.3 months for responders vs. 15.6 months for non-responders, p = 0.03). However, two possible sources of error must be considered: a) the poor prognosis of early responders that may adversely affect the survival of all responders, and b) the bias introduced by the 'guarantee time' of responders (i.e., the time on-study required to detect the response). Exclusion from the analysis of the unfavourable subgroup of 'early' responders (median survival 14.7 mos.) provided an improvement of the difference in survival between the remaining 'slow' responders and non-responders in stage III (p = 0.005) as well as in the series as a whole (p = 0.025). Because of the consistent 'guarantee time' of slow responders, the Mantel-Byar test (which credits survival to responders only after the response has been obtained) was then applied. The survival advantage of slow responders over non-responders, previously observed in all patients, particularly those with stage III, was not confirmed by the Mantel-Byar test (chi-square 0.831 and 1.457, respectively), thus supporting the hypothesis of an equal death rate over time in each response category. It therefore appears that the usual response criteria (which require at least a 50% reduction of the myeloma protein) should perhaps be reassessed, as they seem to be an inadequate parameter for evaluation of treatment effectiveness in multiple myeloma.

The use of interferon for the induction treatment of multiple myeloma has been shown to be effective in about 20 percent of patients. We studied its effects on long-term survival when it was used for maintenance treatment. Between April 1985 and May 1988, 101 patients with symptomatic multiple myeloma who had had a substantial objective response or a lesser objective response with disappearance of symptoms ("disease stabilization") after 12 courses of induction chemotherapy were randomly assigned to receive recombinant interferon alfa-2b as maintenance therapy (n = 50) or to receive no treatment (n = 51). As of December 1989, 66 of the 101 patients have relapsed (25 given interferon and 41 not treated). The median duration of response (from the time of randomization) was 26 months in the patients given interferon and 14 months in the untreated patients (P = 0.0002). A total of 37 patients have died (14 given interferon and 23 not treated). The median duration of survival (from randomization) was 52 months in the interferon group and 39 months in the control group (P = 0.0526). Among the patients who had had a substantial objective response to induction chemotherapy, the difference in survival time was statistically significant (P = 0.03526). Interferon had to be stopped because of toxic effects in 3 of 12 patients initially treated with 10 MU (megaunits) per square meter of body-surface area. After the dose was reduced to 3 MU per square meter, the only toxic effect was a mild influenza-like syndrome lasting two to three weeks. We conclude that maintenance treatment with interferon prolongs response and survival in patients with multiple myeloma who have responded to conventional induction chemotherapy.

The kinetics of bone marrow plasma cells were evaluated by means of in vitro 3(H)thymidine incorporation in 143 patients with monoclonal gammopathies. Fifty-three patients had symptomatic multiple myeloma (MM) at diagnosis, nine were in stable remission, six in unstable remission, and 16 in the relapse phase. Thirty-seven patients were classified has having monoclonal gammopathy of undetermined significance (MGUS) and 22 as smouldering myeloma (SM). A thymidine labelling index (LI%) of greater than 3 at initial diagnosis predicted a very short survival. High LI% values (median 2.8 +/- 1.1) were also seen at relapse. However, the major new finding was that the LI% could be used to discriminate precisely between the SM-MGUS group and the MM patients including stage I disease (P less than 0.0001). Only one patient developed MM during follow up, that being 8 months after the initial diagnosis of SM. During the unmaintained stable remission (plateau) phase a low proliferative activity was also observed (LI% = 0.6 +/- 0.2). Thus the LI% was extremely useful in identification of both poor risk groups with a LI% greater than 3 and stable patients requiring no immediate therapy with a LI% less than 1. The ability to discriminate between MGUS and SM and stage I MM should prove particularly useful clinically.

Blast cells from peripheral blood of 32 patients with acute leukemia were tested for their ability to react with a monoclonal antibody (D1.B6) specific for HLA-DR surface antigen. In order to evaluate the degree of leukemic cell differentiation a monoclonal antibody (R1.B19) specific for the granulocytopoietic lineage was also employed. The results demonstrated that a considerable proportion of blast cell populations expressed the HLA-DR antigen, while only a small fraction of cells expressed the myeloid antigen.

The expression of surface markers was analyzed on human peripheral blood lymphocytes after exposure to 12-O-tetradecanoylphorbol-13-acetate (TPA), a tumor promoter which is known to have a mitogenic effect on human T-cells. A significant decrease in the proportion of cells capable of binding to SRBC under different experimental conditions (active (EA), high affinity (EH), total (ET) rosettes) was observed after 20 hr exposure to TPA. After 4 days incubation, the ability to form EH and ET rosettes was recovered, while a significant increase in the proportion of EA and temperature stable (ES) rosettes compared with control cultures was observed. Using monoclonal antibodies directed against different T-lymphocyte subpopulations, a depression in the proportion of cells reacting with OKT3 (pan T) and OKT4 (helper/inducer) antibodies was observed, after both early and late exposure to TPA. On the contrary, the positivity with OKT8 (suppressor/cytotoxic) antibody was not affected at any time of culture. These findings suggest that, in normal blood, TPA can modulate the expression of T-cell receptors, and that T-lymphocytes with helper/inducer phenotype appear to be the target of the TPA-induced membrane changes.

Simultaneous evaluation of bone marrow plasma cell thymidine labelling index (LI) and serum beta-2-microglobulin (SB2M) was performed in 146 patients with multiple myeloma (MM) or monoclonal gammopathy of undetermined significance (MGUS). Eighty patients had MM on diagnosis, 11 were in relapse and 12 were in remission phase; 43 patients had MGUS. All the evaluated patients had normal renal function with a creatinine level less than 1.4 mg%. Overall there was no direct correlation between LI% and SB2M. LI% best reflected the proliferative capacity of the tumor clone itself being less than or equal to 1% in MGUS and MM in remission, but greater than 2% at relapse of MM. SB2M correlated best with the stage of disease and tumor burden. These two factors therefore have different clinical utility: LI is a useful parameter to detect disease stability (e.g., MGUS) or highly proliferative disease (aggressive MM at diagnosis or early relapse). SB2M remains the best single predictor of patient tumor burden and associated survival duration.