Ph-positive Chronic Myelogenous Leukemia Research Articles

Chronic myelogenous leukaemia with p185(BCR/ABL) expression: characteristics and clinical significance.

We investigated the significance of p185BCR/ABL expression in patients with chronic myelogenous leukaemia (CML) in relation to disease features, therapy and outcome. Results of Western blot analysis for 1384 patients referred with a diagnosis of CML to our institution from 1989 to 1997 were reviewed. Clinical characteristics, results of cytogenetic analysis and RT-PCR for BCR rearrangement were analysed. Five patients with Ph-positive CML expressing the p185BCR/ABL hybrid protein were identified. By RT-PCR, bone marrow specimens of these patients were confirmed to have an e1a2 junction. The median age at diagnosis of these patients was 55 years (range 43-76). All had elevated white cell counts at diagnosis (median 50 x 109/l, range 11.7-163 x 109/l). Four patients had monocytosis (range 10-16%) with a low neutrophil/monocyte ratio in the peripheral blood (range 3.4-5.7). Patients presented with various stages of the disease (two in chronic-phase CP, two in accelerated-phase AP, and one in blastic-phase BP). The clinical course and therapy of the patients varied, with one patient receiving hydroxyurea only, three patients receiving hydroxyurea followed by interferon-alpha based regimens and bone marrow transplantation. The patient presenting in BP was treated with combination chemotherapy. The clinical outcome of the patients was also varied with one patient alive and in complete remission (with complete cytogenetic remission after transplant) and four patients dead after progression to more advanced stages. We conclude that patients with Ph-positive p185BCR/ABL CML frequently present with monocytosis and a low neutrophil/monocyte ratio in the peripheral blood, aiding the speculation that the presence of the p185BCR/ABL hybrid protein may contribute to a phenotype intermediate between CML and CMML. Of interest, the only other specific clinical feature identified was the absence of splenomegaly in four of five patients. There was no definite association with transformation to lymphoid blast phase.

The Risk of Residual Molecular and Cytogenetic Disease in Patients With Philadelphia-Chromosome Positive First Chronic Phase Chronic Myelogenous Leukemia Is Reduced After Transplantation of Allogeneic Peripheral Blood Stem Cells Compared With Bone Marrow

AbstractThe detection of residual molecular and cytogenetic disease was prospectively compared in patients with Philadelphia-chromosome (Ph1) positive first chronic phase chronic myelogenous leukemia (CML) who underwent allogeneic transplantation of unmanipulated peripheral blood stem cells (PBSCT) (n = 29) or bone marrow (BM) (n = 62) using genotypically HLA-identical sibling donors or partially HLA-matched extended family donors. A molecular relapse (MR), as defined by two consecutive positive polymerase chain reaction (PCR) assays for the detection of M-bcr-abl transcripts in a 4-week interval, was found in two of 29 (7%) patients after PBSCT compared with 20 of 62 (32%) patients after bone marrow transplantation (BMT). This corresponds to a 4-year molecular relapse estimate (± standard error) of 7% ± 5% after PBSCT and of 44% ± 8% after BMT (P < .009). With identical follow-up periods of survivors in both patient subsets between 6 and 55 months (median, 28 months), 14 of the 20 patients with MR after BMT progressed to an isolated cytogenetic (n = 10) or a hematologic (n = 4) disease recurrence, resulting in a 4-year cytogenetic relapse estimate of 47% ± 11%, while none of the patients after PBSCT has so far relapsed (P < .006). Multivariate analysis including all potential influencial factors of posttransplant disease recurrence identified the source of stem cells (P < .02) as the only independent predictor of molecular relapse. In conclusion, this prospective comparison of molecular and cytogenetic residual disease demonstrates that peripheral blood stem cell transplants have a more pronounced activity against residual CML cells than bone marrow transplants. Prospective randomized trials comparing PBSCT and BMT in patients with first chronic phase Ph1-positive CML are strictly required to further substantiate differences in the antileukemic activity of the two stem cell sources.

The Risk of Residual Molecular and Cytogenetic Disease in Patients With Philadelphia-Chromosome Positive First Chronic Phase Chronic Myelogenous Leukemia Is Reduced After Transplantation of Allogeneic Peripheral Blood Stem Cells Compared With Bone Marrow

The detection of residual molecular and cytogenetic disease was prospectively compared in patients with Philadelphia-chromosome (Ph1) positive first chronic phase chronic myelogenous leukemia (CML) who underwent allogeneic transplantation of unmanipulated peripheral blood stem cells (PBSCT) (n = 29) or bone marrow (BM) (n = 62) using genotypically HLA-identical sibling donors or partially HLA-matched extended family donors. A molecular relapse (MR), as defined by two consecutive positive polymerase chain reaction (PCR) assays for the detection of M-bcr-abl transcripts in a 4-week interval, was found in two of 29 (7%) patients after PBSCT compared with 20 of 62 (32%) patients after bone marrow transplantation (BMT). This corresponds to a 4-year molecular relapse estimate (± standard error) of 7% ± 5% after PBSCT and of 44% ± 8% after BMT (P &lt; .009). With identical follow-up periods of survivors in both patient subsets between 6 and 55 months (median, 28 months), 14 of the 20 patients with MR after BMT progressed to an isolated cytogenetic (n = 10) or a hematologic (n = 4) disease recurrence, resulting in a 4-year cytogenetic relapse estimate of 47% ± 11%, while none of the patients after PBSCT has so far relapsed (P &lt; .006). Multivariate analysis including all potential influencial factors of posttransplant disease recurrence identified the source of stem cells (P &lt; .02) as the only independent predictor of molecular relapse. In conclusion, this prospective comparison of molecular and cytogenetic residual disease demonstrates that peripheral blood stem cell transplants have a more pronounced activity against residual CML cells than bone marrow transplants. Prospective randomized trials comparing PBSCT and BMT in patients with first chronic phase Ph1-positive CML are strictly required to further substantiate differences in the antileukemic activity of the two stem cell sources.

ALL- and CML-type BCR/ABL mRNA transcripts in chronic myelogenous leukemia and related disorders

Using the reverse transcription polymerase chain reaction, we investigated acute lymphoid leukemia (ALL)-type, and chronic myelogenous leukemia (CML)-type BCR/ABL mRNA expression in a total of 66 patients with chronic myeloproliferative disorder (CMPD). Thirty-six of 37 patients with CML were positive for CML-type mRNA. Thirteen of the 25 CML had ALL-type mRNA expression. The patients with ET, PV, MF, and CMML did not have any detectable BCR/ABL expression. The most remarkable finding was that two patients, a Ph1-positive CML patient and a patient with a presumptive diagnosis of essential thrombocythemia (ET), showed only ALL-type chimeric mRNA expression.

Low megakaryocyte ploidy in Ph-positive chronic myelogenous leukemia measured by flow cytometry.

In chronic myeloproliferative disorders, the megakaryocytes differ in size and maturation compared with those of healthy individuals. In the present study, by using a 2-color flow cytometry technique, we determined the frequency of bone marrow megakaryocytes in different ploidy classes in 13 newly diagnosed and untreated patients with Philadelphia chromosome (Ph)-positive chronic myelogenous leukemia (CML) and in 12 healthy volunteers. The results showed a significant difference in megakaryocyte ploidy distributions between these 2 study groups. On the average, patients with CML had 59% of their megakaryocytes in ploidy classes 2N to 8N; in contrast, the healthy volunteers had only 22% of their megakaryocytes in classes 2N to 8N. Two patients with complex Ph translocation and 2 patients with a small clone with a chromosome abnormality in addition to Ph had the same ploidy distribution as those with only Ph translocation. The platelet count did not correlate with the megakaryocyte mean ploidy.

Frequency of Clonal B Lymphocytes in Chronic Myelogenous Leukemia Evaluated by Fluorescence In Situ Hybridization

The demonstration of the Philadelphia (Ph) chromosome in B lymphocytes from patients with chronic myelogenous leukemia (CML) has provided evidence that the disorder originates in a pluripotent progenitor cell. Divergent results, however, exist as to the degree of contribution of clonally derived cells to the B-cell compartment. To address this issue, B lymphocytes were selected from the blood of seven patients in the chronic phase of Ph-positive CML and were examined with dual-color fluoresence in situ hybridization for the presence of the Ph translocation. The purity of the B-cell preparations ranged from 88% to 97% (mean 93%). The Ph translocation was detected in 22–34% (mean, 27%) of the sorted B cells. There was no evidence that the duration of the disease affects the ratio of Ph-positive and -negative B cells. In summary, clonally derived circulating B lymphocytes were present in all patients studied but made only minor contribution to this compartment.

Early treatment decisions with interferon-alfa therapy in early chronic-phase chronic myelogenous leukemia.

To determine, in patients with Philadelphia chromosome (Ph)-positive chronic myelogenous leukemia (CML) on interferon alfa (IFNalpha), whether combining pretreatment characteristics and early response profiles would distinguish patients with differential benefits that would allow better decisions on subsequent therapy. A total of 274 patients treated from 1982 through 1990 with IFNalpha regimens were analyzed. A second group of 137 patients treated with IFNalpha and low-dose cytarabine (ara-C) between 1990 and 1994 was later used to confirm the guidelines derived from the original study group analysis. Patients' pretreatment factors and response to IFNalpha therapy at 3, 6, and 12 months were analyzed in relation to subsequent achievement of major cytogenetic response. After univariate analysis of prognostic factors, a multivariate analysis selected, at 6 months, independent pretreatment factors that added to the response status in predicting subsequent outcome. The results were then applied at the 3- and 12-month periods and confirmed in the subsequent population. Response to IFNalpha therapy at 3, 6, and 12 months was a significant predictor of later major cytogenetic response. The presence of splenomegaly > or = 5 cm below the costal margin (BCM) or thrombocytosis > or = 700 x 10(9)/L pretreatment added significant independent prediction to response. At 6 months, patients with a partial hematologic response (PHR) or resistant disease had a less than 10% chance of achieving a later major cytogenetic response, as were those in complete hematologic response (CHR) and who had pretreatment splenomegaly and thrombocytosis. Applying the model at 3 months showed that only patients with < or = PHR and pretreatment splenomegaly or thrombocytosis at 3 months had such a low major cytogenetic response rate. Finally, at 12 months, patients with CHR still had a 15% to 25% chance of having a major cytogenetic response later if they did not have pretreatment splenomegaly and thrombocytosis. This analysis allows better selection of patients with Ph-positive CML on IFNalpha therapy for continuation of IFNalpha versus changing therapy early in the course of CML. For treatment programs that choose to change patients to other investigational therapies (eg, intensive chemotherapy and/or autologous stem-cell transplantation [SCT]), baseline outcome expectations are provided for patients continued on IFNalpha therapy, against which the results of new approaches can be compared.

Clonal development of myeloproliferative disorders: clues to hematopoietic differentiation and multistep pathogenesis of cancer.

In November 1996, word reached the University of Washington that Philip Fialkow and his wife, Helen, had died while trekking in Nepal. Over a 30-year period, Dr Fialkow and his colleagues used the cellular mosaicism resulting from X-chromosome inactivation in females as a marker system to investigate the clonal development of human hematopoietic disorders. This review discusses the impact that these studies have had on our understanding of hematopoietic stem cell relationships and the pathogenesis of human neoplasia in general. To appreciate the special role played by studies on clonality, it is necessary to consider how little was known about the origin of leukemias and myeloproliferative disorders and the limited techniques available for their study in the early to mid 1960s. Dr Fialkow and his coworkers were the first to show that myeloproliferative disorders and acute myelogenous leukemias (AML) are clonal diseases at the time of diagnosis and to elucidate the level of differentiation manifested by the originating cell type. Although the myelodysplastic disorders were found to involve a pluripotent stem cell, heterogeneity was found in the level of stem cell involvement in AML. Evidence was obtained to support a multistep pathogenesis of these diseases as well as a clonal but cytogenetically normal stage in some cases of Ph-positive chronic myelogenous leukemia, AML, acute lymphoblastic leukemia and myelodysplasia.

A pilot study of all-trans retinoic acid in patients with Philadelphia chromosome-positive chronic myelogenous leukemia.

Retinoids have significant antiproliferative effect against chronic myelogenous leukemia (CML) cells in vitro. We conducted a pilot study to investigate the clinical effect of all-trans retinoic acid (ATRA) in patients with CML. Thirteen patients with Philadelphia chromosome (Ph)-positive CML in late chronic phase (n=7), accelerated phase (n=5), or blastic phase (n=1) were treated. All had been previously treated and 12 (92%) had disease refractory to interferon-alpha therapy. They received ATRA 175 mg/m2 orally in two divided doses daily until disease progression. The median duration of therapy was 56 days (range 11 to 190). Only one patient in late chronic phase had a transient decrease in WBC counts; all other patients in late chronic phase showed no response to therapy. Four of the five patients in accelerated phase showed evidence of antileukemia effect manifested by a decrease in bone marrow and/or peripheral blood blasts, promyelocyte and/or basophil percentages. In all cases the response was transient. The patient in blastic phase had no evidence of antileukemic effect. The treatment was well tolerated with the major side-effects being headache, nausea, dry skin, and dry mucosal membranes. One patient required dose reductions due to toxicity. We conclude that in this population of patients with extensively treated, advanced stage, Ph-positive CML, ATRA alone is ineffective for long-term therapy. The antileukemia effect seen in some patients warrants further investigation of retinoids in other schedules and in combinations in patients with CML.

Mobilization and transplantation of Philadelphia-negative peripheral-blood progenitor cells early in chronic myelogenous leukemia.

Mobilization of Philadelphia (Ph) chromosome-negative progenitors is now possible in many Ph1-positive chronic myelogenous leukemia (CML) patients who had received interferon alfa (IFN-alpha) with no cytogenetic response. In this pilot study, we used this approach in patients without prior IFN-alpha therapy to determine if the number and quality of mobilized progenitors would be increased and to evaluate the potential effect of these cells as autografts. Twenty-two untreated patients were mobilized within 12 months of diagnosis. The treatment regimen consisted of the mini-ICE protocol. Beginning on day +8, granulocyte colony-stimulating factor (G-CSF) was used in all patients. Leukophoresis was performed as the patients were recovering from aplasia, when WBC count exceeded 0.8 x 10(9)/L. In 14 patients, (63%) the leukophoresis product was entirely Ph1-negative and in four patients the Ph1-positive cell rate was < or = 7%. Significant numbers of long-term culture-initiating cells (LTC-IC) and CD34+ Thy1+Lin- cells were found in most of the Ph1-negative collections that were tested. Twelve patients underwent autografting with their mobilized peripheral-blood progenitor cells (PBPC) (Ph1-negative collections, 10 patients; major cytogenetic response, two patients). All patients engrafted and are alive; six have Ph1-negative marrow 7 to 15 months after autografting. Posttransplant treatment was IFN-alpha combined with interleukin (IL)-2 because of the recent demonstration of synergistic activity in augmenting cytolytic activity. Intensive chemotherapy given in early chronic phase of CML is well tolerated and results in high numbers of circulating Ph1-negative precursor cells.

Interferon-alpha-2C and LD ara-C for the treatment of patients with CML: Results of the austrian multicenter phase II study

Small pilot studies of patients with CML have reported on encouraging response rates after treatment with interferon-alpha (IFNα) in combination with low-dose cytosine arabinoside (LD ara-C). We therefore initiated a multi-center phase II trial in order to investigate the efficacy and tolerability of this combination in newly diagnosed patients with Ph-positive chronic myelogenous leukemia (CML). Eighty-four patients were treated with IFN-α-2c at daily subcutaneous doses of 3.5 MU and LD ara-C added subcutaneously for 10 days every month at a dose of 10 mg/m 2, following an initial reduction of WBC to less than 20 × 10 9/l with hydroxyurea (HU). Within a median observation period of 28 (5–59) months the patients received a median of 7 (1–35) IFNα and LD ara-C cycles. Treatment was stopped due to side effects in 16 cases (19%) and to primary or secondary treatment failure in 38 cases (45%). In 45 patients (54%) complete hematological response (CHR) was achieved; in 39 patients (46%) cytogenetic responses including 15 (18%) complete cytogenetic responses (CHR) were observed. Median duration of cytogenetic responses was 15 months. Relapses were seen in 8 15 patients (53%) with complete cytogenetic remission (CCR), in 3 6 patients (50%) with partial cytogenetic response and in 9 18 patients (50%) with minor cytogenetic response. In conclusion, the combination of IFNα and LD ara-C resulted in encouraging rates of hematological and cytogenetic responses in patients with CML with low to moderate toxicity.

Microdissection-mediated selection of chromosome region-specific cDNAs.

K562 is a cell line with two acrocentric marker chromosomes containing abnormally banded regions (ABRs), derived from a Ph-positive chronic myelogenous leukemia (CML) patient. Using reverse and forward chromosome painting FISH analysis, we found that 9q34, 13q31, and 22q11 regions co-amplified in the ABRs-bearing acrocentric marker chromosomes of K562. Utilizing the ABRs of the cell line as target DNA for cDNA selection, we established a simple procedure for chromosome region-specific cDNA isolation. After first strand cDNA synthesis from fetal brain mRNAs, short fragment cDNAs (sf-cDNAs) were synthesized with a two-step amplification system by use of our modified Degenerate Oligonucleotide Primed Shuttle Polymerase Chain Reaction (DOP-Shuttle-PCR) method. The sf-cDNAs were hybridized onto RNase A treated metaphases from K562, and the ABRs were microdissected and reamplified with DOP-Shuttle-PCR primer-II. The reamplified sf-cDNAs were cloned into a pBluescript vector. Twenty randomly chosen clones were sequenced and classified into 8 groups. Three out of the 8 grouped clones had been mapped to the long arm of chromosome 22 (22q11), whereas the other 5 were novel cDNAs. Quantitative Southern blot analysis indicated that 7 out of the 8 grouped clones (87.5%) were derived from the co-amplified regions.

IN VIVO MOBILIZATION OF KARYOTyPICALLY NORMAL PERIPHERAL BLOOD PROGENITOR CELLS IN HIGH‐RISK MDS, SECONDARY OR THERAPY‐RELATED ACUTE MYELOGENOUS LEUKAEMIA

We have previously reported that mobilization of Philadelphia (Ph) chromosome-negative progenitors is possible in a significant number of Ph1-positive acute lymphoblastic leukaemia (ALL) and chronic myelogenous leukaemia (CML) patients. In this pilot study we employed the same approach for patients with RAEB-t, secondary AML (sAML) and therapy-related AML (t-AML). All patients except one had double or complex cytogenetic abnormalities in marrow cells before mobilization therapy. All patients received an idarubicin-containing regimen (mini-ICE protocol) followed by rh-G-CSF and the first leukapheresis was performed as they were recovering from aplasia. In six out of nine patients the leukapheresis product was entirely karyotypically normal, combined with a significant number of CFU-GM. CD34+ cells and LTC-IC. Recovery time from mobilization therapy was short and no patient died as a result of the procedure. To date, three patients have undergone autografting using their karyotypically normal collections, of which two (sAML) are alive with karyotypically normal marrow a few months after autografting.

Immune-mediated and unusual complications during interferon alfa therapy in chronic myelogenous leukemia.

Long-term treatment with interferon alfa (IFN alpha) can produce or exacerbate immune-mediated complications (IMC). The purpose of this study was to analyze the experience with IMC and unusual complications in patients with chronic myelogenous leukemia (CML) undergoing IFN alpha treatment. The occurrence of IMC and unusual complications was evaluated in patients with Philadelphia chromosome (Ph)-positive CML. Well-documented and clinically evident complications developed in 35 patients after a median of 14 months of IFN alpha treatment. These included 28 (5%) of 581 patients with Ph-positive CML treated with IFN alpha-containing regimens at M.D. Anderson Cancer Center (MDACC) and seven patients referred for opinion or problems who were on other studies. Hypothyroidism occurred in 11 patients (2%), immune-mediated hemolysis in seven (1%), and connective tissue diseases in 11 (2%). Other unusual occurrences included congestive heart failure (CHF; n = 4), porphyria cutanea tarda (PCT; n = 3), membranous glomerulonephritis (MGN; n = 1), and vitiligo (n = 1). IFN treatment was discontinued in 19 patients and the dose was reduced in five. Ten of 11 patients (91%) with immune-mediated hypothyroidism and eight of 11 (73%) with connective tissue diseases had some degree of cytogenetic response at the time of the event. Although the frequency of IMC is low, patients treated with IFN alpha should be monitored for signs and symptoms of autoimmunity.

Translocation 11;14 in newly diagnosed chronic myelogenous leukemia

In patients with chronic myelogenous leukemia (CML), the Philadelphia chromosome may be associated with a number of other cytogenetic lesions. However, t(11;14)(g13;g32), found mainly in B-cell lymphoproliferative disorders, has not been previously reported in Ph-positive CML. We describe a patient with hematologically typical chronic phase CML in whom both cytogenetic lesions were found at diagnosis.

Collection of peripheral-blood diploid cells from chronic myelogenous leukemia patients early in the recovery phase from myelosuppression induced by intensive-dose chemotherapy.

To evaluate whether intensive chemotherapy followed by peripheral stem-cell (PSC) collections during early hematopoietic recovery results in a higher percentage of diploid cell collections in patients with Philadelphia chromosome (Ph)-positive chronic myelogenous leukemia (CML). Fifty-five adults with Ph-positive CML received intensive chemotherapy with daunorubicin and high-dose cytarabine (ara-C) (DAUNO-HDAC; 26 patients) or fludarabine, high-dose ara-C, and mitoxantrone (FAM; 29 patients). Collections of the peripheral mononuclear cells were initiated when the WBC count was > or = 0.8 x 10(3)/microL. Simultaneous peripheral and marrow samples were subjected to cytogenetic studies. Thirty-eight of 55 patients (69%) were able to undergo the PSC collections. The rate of collection was higher in chronic phase (26 of 30 patients; 87%) than in accelerated (11 of 17; 65%) and blastic phases (1 of 8; 12%). Among the 30 patients in chronic phase, cytogenetic analyses of PSC showed cytogenetic responses (Ph-positive < 95%) in 60%, which were major (Ph < 35%) in 43% and complete (Ph = 0%) in 27%. Seven of 19 patients with simultaneous studies (37%; 23% of total) had a significantly lower percentage of Ph-positive cells in the peripheral collection compared with the marrow collection; one had the reverse phenomenon (5%; 3% of total). Cytogenetic responses were modest in both peripheral and marrow collections in CML accelerated and blastic phases. Myelosuppression-associated complications were frequent, resulting in febrile episodes in 76% of patients. PSC collection during early hematopoietic recovery from intensive chemotherapy allowed the collection of diploid-rich stem cells, mostly in chronic-phase CML. The approach could be used for in vivo purging before autologous stem-cell transplantation (ASCT).

Philadelphia chromosome-negative chronic myelogenous leukemia with rearrangement of the breakpoint cluster region. Long term follow-up results

Five to 10% of patients with chronic myelogenous leukemia (CML) do not have the Philadelphia chromosome (Ph), but one-third of them have rearrangements of the breakpoint cluster region (BCR-positive). The authors analyzed the characteristics, treatment response, and prognosis of 23 patients with BCR-positive, Ph-negative CML, and compared them with patients with Ph-positive CML, Ph-negative BCR-negative CML and chronic myelomonocytic leukemia (CMML) treated during the same period. Seventeen patients had early chronic phase CML, 3 had late chronic phase, 2 had accelerated phase, and 1 had blastic phase. The median age was 44 years (range, 14-71 years), median platelet count was 402 x 10(9)/l, and median leukocyte count was 86 x 10(9)/l. Fourteen of the 17 patients with early chronic phase CML received alpha-interferon; 12 (86%) achieved complete hematologic remission. Median survival in chronic phase CML was 60 months (range, 3-90+ months). Patients with Ph-negative BCR-positive CML and those with Ph-positive CML had similar characteristics and outcome. Compared with patients with Ph-negative BCR-negative CML and CMML, patients with Ph-negative BCR-positive CML and Ph-positive CML were significantly younger, had a significantly higher incidence of leukocytosis, thrombocytosis, and peripheral and marrow basophilia, and a significantly lower incidence of anemia, thrombocytopenia, marrow blast percent, and peripheral and marrow monocytosis. The median survival was 60 months for Ph-negative BCR-positive CML, 73 months for Ph-positive CML, 25 months for Ph-negative BCR-negative CML, and 9 months for CMML (P < 0.001). When analyzed adjusting for their stage, patients classified with Ph-negative BCR-positive CML. Stage I disease had a significantly better survival than did patients with Ph-negative BCR-negative CML (P < 0.02). Patients with Ph-negative BCR-positive CML are similar to those with Ph-positive CML and should be treated with the same approaches.

Case report of spontaneous remission of cytogenetic relapse of chronic myelogenous leukemia suggestive of progression to blast crisis after allogeneic bone marrow transplantation

Detection of the chronic myelogenous leukemia (CML)-related marker, the bcr/abl m-RNA transcript, in blood or bone marrow of patients with CML in hematologic remission after allogeneic bone marrow transplantation (allo-BMT) may be associated with the presence of minimal residual disease but does not uniformly predict hematologic relapse. In contrast, when there is cytogenetic reappearance of the Philadelphia (Ph1) translocation [t(9;22)(q34;q11)] along with additional cytogenetic abnormalities, especially more than 2 years after BMT, progression to hematologic relapse and acceleration of CML usually occur. An exception to this rule may be our patient, who was a 29-year old white woman diagnosed with Ph1-positive CML by cytogenetics. She was initially treated with hydroxyurea. An allo-BMT was performed 4 months after the diagnosis, while the patient was still in the first chronic phase of her disease, her HLA-identical brother serving as bone marrow (BM) donor. The conditioning regimen for BMT consisted of cytosine arabinoside, cyclophosphamide, total body irradiation, splenic irradiation, and intrathecal methotrexate. Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporin A and methotrexate. Her hospital course was unremarkable and without evidence of acute GVHD. Six months after transplantation, the patient had mild chronic GVHD and was treated with azathioprine and prednisone for 6 months. A year later, she recurred with mild chronic GVHD. She was treated with azathioprine alone for 5 months. Subsequently, she received cyclosporin A and prednisone for 8 months, with resolution of her symptoms. Serial BM cytogenetic studies showed normal male donor karyotypes 12 and 24 months after BMT. At 36, 42, and 50 months after BMT, reappearance of the Ph1 was noted along with some cells with additional cytogenetic abnormalities, including t(6;14)(p21;q32). The breakpoint involvement of 14q32, the heavy chain Ig locus, in the new clone may be indicative of B-lymphoid lineage-based evolution. The abnormal clones disappeared 56 months from BMT and remained absent through 69 months after BMT. The patient has remained in hematologic remission during her entire post-BMT course. Clinically, she continues to do well without immunosuppressants at presently 69 months after BMT. The reappearance of the Ph1 chromosome could be associated with the immunosuppressive therapy given for chronic GVHD. This case supports the concept that immunologic mechanisms may be important in the eradication of CML after allo-BMT, and even cytogenetic evidence of blast crisis CML may spontaneously remit after allo-BMT.

Soluble HLA class I and beta-2-microglobulin plasma concentrations during interferon treatment of chronic myelogenous leukemia.

Soluble class I molecules (sHLA-ABC) were measured by an enzyme-linked immunosorbent assay (ELISA) in plasma samples of 13 patients with chronic-phase Ph1-positive chronic myelogenous leukemia (CML). The patients were treated once daily with interferon (IFN) s.c. at a dosage of 4 x 10(6) IU/m2 IFN-alpha-2b or in combination with 50 micrograms IFN-gamma. Measurements were performed before 2, 4, 6, 8, 24, 48, and 72 h after the start of treatment and thereafter every 2-4 weeks. Baseline sHLA-ABC levels were within normal limits (mean 22.1 +/- 8.8 mg/l). An initial decrease of sHLA-ABC (mean 3.2 +/- 2.7 mg/l) was seen in all patients during the first 2-8 h of IFN treatment. Thereafter, sHLA-ABC levels increased steadily reaching maximum values within 2-5 weeks. The overall increase was 12.7 +/- 12.4 mg/l. During the following 2-4 months of IFN treatment sHLA-ABC decreased to near baseline levels in 12 of 13 patients. No difference was detected between IFN-alpha and IFN-alpha plus IFN-gamma treatment. beta 2-Microglobulin values were measured in 8 patients and were found to be correlated to sHLA-ABC concentrations (r = 0.48).

Persistence of dormant leukemic progenitors during interferon-induced remission in chronic myelogenous leukemia. Analysis by polymerase chain reaction of individual colonies.

Interferon-alpha induces durable cytogenetic remissions in about one-quarter of newly diagnosed patients with chronic myelogenous leukemia (CML). Even so, after short-term follow-up, previous studies have shown that residual leukemic cells can be detected by the polymerase chain reaction (PCR) in all of these individuals. The objectives of our study were therefore to obtain long-term follow-up data on residual disease in a cohort of complete responders and to determine if leukemic cells with clonogenic potential are present in patients despite the absence of relapse. We performed (a) serial analysis of blood and/or bone marrow for a reverse transcriptase PCR amplified BCR-ABL transcript at times well beyond the point that cytogenetic remission was first attained and (b) reverse transcriptase PCR of individually plucked myeloid and erythroid colonies for the presence of the same transcript. Seven CML patients who had previously attained complete cytogenetic remission while on interferon-alpha were investigated. Six of the seven patients were in complete cytogenetic remission at the time of analysis, whereas one patient had early evidence of cytogenetic relapse. With ongoing therapy, five patients with the longest follow-up eventually achieved PCR negativity at time periods of 27, 32, 36, 49, and 67 mo after a complete cytogenetic remission was first noted. Even so, residual disease was detected in progenitor cells derived from two patients, each of whom had been in continuous cytogenetic remission for approximately 2.5 and 3.5 yr, respectively. Progenitors expressing BCR-ABL transcripts were also detected in the patient with early cytogenetic relapse. These observations demonstrate that residual disease resides in colony-forming cells that should have the potential to repopulate the bone marrow. However, the presence of a minority of Ph-positive CML progenitor cells for a very long period of time is still compatible with durable remission, confirming that a situation of tumor dormancy may be induced in CML by interferon therapy.