Chronic Granulocytic Leukemia Patients Research Articles

The association between FOXO3a rs4946936 gene polymorphism and the levels of FOXO3a among chronic granulocytic leukemia patients treated with imatinib mesylate

Background: The gene FOXO3a has been elucidated to govern the development of chronic granulocytic leukemia (CGL). Moreover, it has been suggested that the levels of FOXO3a in circulation are affected by the FOXO3a rs4946936 gene polymorphism. However, no study has assessed the correlation between the FOXO3a rs4946936 gene polymorphism and the levels of FOXO3a. The objective of this study was to assess the association between the FOXO3a rs4946936 gene polymorphism and the levels of FOXO3a in CGL patients treated with imatinib mesylate. Methods: A cross-sectional study was conducted from February 2019 to February 2020. The genotyping of FOXO3a rs4946936 gene polymorphism was conducted using PCR-RFLP, and the levels of FOXO3a were assessed using ELISA. The association between the FOXO3a rs4946936 gene polymorphism and the levels of FOXO3a were assessed using multiple logistic regression. Results: A total of 60 CGL patients were assessed in our study. Among them, the CC, CT, and TT genotypes of the FOXO3a rs4946936 gene polymorphism were 35.0%, 48.3%, and 16.7% respectively. Our calculation revealed that elevated levels of FOXO3a were found in CGL patients with the CC genotype of the FOXO3a rs4946936 gene polymorphism. While we failed to clarify the association between either the CT or the TT genotype of FOXO3a rs4946936 gene polymorphism and the levels of FOXO3a. Conclusion: Our study identifies that the CC genotype of the FOXO3a rs4946936 gene polymorphism affects the elevated levels of FOXO3a in CGL patients treated with imatinib mesylate.

The association between FOXO3a rs4946936 gene polymorphism and the levels of FOXO3a among chronic granulocytic leukemia patients treated with imatinib mesylate

Background: The gene FOXO3a has been elucidated to govern the development of chronic granulocytic leukemia (CGL). Moreover, it has been suggested that the levels of FOXO3a in circulation are affected by the FOXO3a rs4946936 gene polymorphism. However, no study has assessed the correlation between the FOXO3a rs4946936 gene polymorphism and the levels of FOXO3a. The objective of this study was to assess the association between the FOXO3a rs4946936 gene polymorphism and the levels of FOXO3a in CGL patients treated with imatinib mesylate. Methods: A cross-sectional study was conducted from February 2019 to February 2020. The genotyping of FOXO3a rs4946936 gene polymorphism was conducted using PCR-RFLP, and the levels of FOXO3a were assessed using ELISA. The association between the FOXO3a rs4946936 gene polymorphism and the levels of FOXO3a were assessed using multiple logistic regression. Results: A total of 60 CGL patients were assessed in our study. Among them, the CC, CT, and TT genotypes of the FOXO3a rs4946936 gene polymorphism were 35.0%, 48.3%, and 16.7% respectively. Our calculation revealed that elevated levels of FOXO3a were found in CGL patients with the CC genotype of the FOXO3a rs4946936 gene polymorphism. While we failed to clarify the association between either the CT or the TT genotype of FOXO3a rs4946936 gene polymorphism and the levels of FOXO3a. Conclusion: Our study identifies that the CC genotype of the FOXO3a rs4946936 gene polymorphism affects the elevated levels of FOXO3a in CGL patients treated with imatinib mesylate.

The association betweenFOXO3ars4946936 gene polymorphism and the levels ofFOXO3aamongchronicgranulocyticleukemia patients treated with imatinib mesylate.

Background:The gene FOXO3ahas been elucidated to govern the development ofchronicgranulocyticleukemia(CGL). Moreover,it has been suggested thatthe levels of FOXO3ain circulationareaffected bythe FOXO3ars4946936gene polymorphism. However, no studyhasassessed the correlation betweenthe FOXO3ars4946936gene polymorphism and the levels of FOXO3a.The objective of this study was to assess the association between the FOXO3ars4946936gene polymorphism and the levels of FOXO3ain CGL patients treated with imatinib mesylate. Methods: A cross-sectional study was conductedfromFebruary 2019toFebruary 2020. The genotyping of FOXO3ars4946936gene polymorphism was conducted using PCR-RFLP, and the levels of FOXO3awereassessed using ELISA. The association between the FOXO3ars4946936gene polymorphism and the levels of FOXO3awereassessed using multiple logistic regression. Results:A total of 60 CGL patientswereassessedin our study. Among them, the CC, CT, and TT genotypes ofthe FOXO3ars4946936gene polymorphism were35.0%,48.3%,and16.7% respectively. Our calculation revealed that elevated levels of FOXO3awerefound in CGL patients withtheCC genotypeofthe FOXO3ars4946936gene polymorphism. While we failed to clarify the association between eithertheCTortheTT genotypeof FOXO3ars4946936gene polymorphismand the levels of FOXO3a. Conclusion: Our study identifies thattheCC genotype ofthe FOXO3ars4946936gene polymorphism affects the elevated levels of FOXO3ain CGL patients treated with imatinib mesylate.

Effects of the FOXO3a rs 4946936 Gene Polymorphism on the FOXO3a Transcription Factor in Chronic Granulocytic Leukemia Patients

Introduction : FOXO3a has an important role in the maintenance of leukemic stem cells. BCR-ABL inhibition therapy by TKI dasatinib aims to reduce the phosphorylation of the transcription factor FOXO3a, promote localization of FOXO3a in the nucleus and restore transcriptional activity. However, some studies showed that the TKI dasatinib, in addition to increase the relocation of Foxo3a to the intranuclear, also increase the expression of CDKN1c/p57 and Bcl6 genes that became the down target for Foxo3a intra nucleus ATM. Therefore, current therapy is mostly directed at personalized therapy (personalized medicine). The aim of this study was to investigate the effect of the FOXO3a rs4946936 gene polymorphism on the Foxo3a transcription factor in chronic granulocytic leukemia patients treated with Imatinib mesylate.
 Method : This is a cross-sectional study in patients with chronic granulocytic leukemia (CGL) with positive Bcr-ABL. The aim was to prove the effect of the FOXO3a gene polymorphism rs4946936 on the Foxo3a transcription factor. The data analysis test used was a correlation test and a regression test.
 Result : There were three polymorphisms of the FOXO3a gene, namely CC polymorphism, TC polymorphism, and TT polymorphism with a p-value of 0.026 and an r of 0.287, so it can be concluded that there was a significant correlation between the FOXO3a gene polymorphism and the Foxo3an transcription factor with a sufficient correlation value. In the regression test between the FOXO3a gene polymorphisms and the transcription factor FOXO3a, the p value was 0.029 and the B value was -0.294. This means that it has a negative and significant effect on the Foxo3a transcription factor variable.
 Conclusion : There was a significant correlation between the gene polymorphism FOXO3a rs4946936 and the transcription factor FOX3a. The FOXO3a gene polymorphism of the TT genotype had a negative effect on the FOXO3a transcription factor. The TT gene in the FOXO3a gene polymorphism was the most effective in reducing the FOXO3a transcription factor.

Global Longitudinal Strain of Chronic Granulocytic Leukemia Patients treated with Imatinib and Nilotinib

Objective: To determine left ventricular function of patients with Chronic Granulocytic Leukemia in Chronic Phase (CGL-CP) who received imatinib and nilotinib by using Global Longitudinal Strain (GLS) examination. Methods: This was a descriptive study involving 46 CGL-CP patients who received imatinib and nilotinib therapy at the Hemato-Oncology Clinic of the Internal Medicine Departement of Dr. Hasan Sadikin General Hospital,, Bandung, Indonesia. Sampling was performed consecutively during the period of October to December 2019. Variables assessed in this study were age, gender, BMI, length of treatment, hemoglobin level, Left Ventricular Ejection Fraction (LVEF) value, and Global Longitudinal Strain (GLS). Primary data were tested for normality using the Saphiro-Wilk test. Statistical analysis was performed using SPSS software version 25.0. Results: Thirty-nine patients (seventeen males and twenty-two females with a mean age of 42±11) who had been in therapy for about 8 to 179 months at the time of the study were included as subjects. On average, the GLS results for both treatment groups indicated a normal value based on the classification of the American Society of Echocardiography. The imatinib group gained a score of -22.4% (average range = -16.4% to (-28.1%)), while the nilotinib group gained a score of -21.6% (average range = -18.0% to (-25.9%)). Conclusion: This study described the left ventricular function based on results of GLS in CGL-CP patients receiving imatinib and nilotinib.

Differences of Bone Marrow Features and BCR-ABL Variants in Chronic Granulocytic Leukemia Post Tyrosine Kinase Inhibitor Therapy

Chronic Granulocytic Leukemia (CGL) occurs due to chromosomal translocation (9;22) known as Philadelphiachromosome. p210 BCR-ABL1 oncogenes are classified into b2a2 and b3a2 transcripts which possibly lead to differentclinical manifestations and response to therapy. This study was aimed to prove that there is a difference in bone marrowfeatures and BCR-ABL between remissive and resistant CGL after Tyrosine Kinase Inhibitor (TKI) therapy. This research wasan observational study with a cross-sectional design carried out at Ulin Hospital Banjarmasin on 32 subjects. BCR ABL wasdetected by using PCR and bone marrow features were assessed by using bone marrow aspiration technique. The differencebetween bone marrow features and BCR-ABL variants was analyzed by using the T-test (p < 0.005) and Chi-Square(p < 0.005), respectively. There was a difference of BCR-ABL variants with p=0.091 and characterized by M:E ratio (p=0.124),myeloblast count (p=0.063), and eosinophil count (p=0.055). Also, there was a difference of bone marrow cellularity(p=0.000) and basophil count (p=0.016) between remissive CGL and resistant CGL patients. There was no difference in BCRABL variants, myeloblast count and eosinophil count between remissive CGL and resistant CGL patients. However, there wasdifferent of bone marrow cellularity and basophil count between remissive CGL and resistant CGL patients.

Long-term effect of homoharringtonine on chronic granulocytic leukemia

Objective: To observe the long-term effect of homoharringtonine (HHT) on chronic granulocytic leukemia (CGL) and its pharmacological mechanism. Methods: 76 patients with newly diagnosed early chronic phase CGL received treatment of merely 1.5 mg/m2 daily HHT for induction remission and long-term maintenance treatment. The apoptosis rate of bone marrow CD34+ cells induced by HHT was assayed with flow cytometer. Results: 86.8% patients achieved CHR, 13.2% patients PHR and 31.8% patients got cytogenetic response in HHT treatment group, which was longer than 31 (8–54) months in hydroxyurea (HU) group (P<0.05). The effect of apoptosis induction HHT was stronger on CGL-CP patients bone marrow CD34+ cells than on normal person bone marrow CD34+ cells. Conclusion: HHT is a very effective drug for remission induction and long-term maintenance treatment in early chronic phase CGL patients.

Amplification of mitochondrial DNA in acute myeloid leukaemia.

There is a long-standing interest in the possible role of mitochondria in malignancy. We sought to discover whether amplification of mitochondrial DNA (mtDNA) occurred in leukaemia, and found it was often remarkably amplified in the blast cells of acute myeloid leukaemia (AML). We used gene dosage experiments to quantify the amount of mtDNA relative to nuclear DNA. DNA extracted from peripheral blood leucocytes or bone marrow of healthy individuals or patients was simultaneously hybridized with a probe for the mitochondrial genome and a control probe for the renin gene on human chromosome 1. Comparative densitometric ratios of approximately 1 were obtained between the two signals in 20 normal control peripheral blood samples. In contrast, comparative ratios in the range of 2-50 were observed in 25 AML samples and 13 of these showed 8-fold or greater amplification of mtDNA relative to normal peripheral blood controls. An additional four cases of AML were investigated at both presentation and remission and showed 3-10-fold amplification of mtDNA at presentation, but no amplification when in clinical remission. 18 cases of chronic granulocytic leukaemia (CGL) were also studied in chronic phase and showed mtDNA dosage levels equivalent to normal peripheral blood controls. However, 8/9 CGL patients showed mtDNA amplification during transformation from chronic phase. We conclude that amplification of mtDNA is an invariable feature of acute myeloid leukaemia and that it may be a useful marker for detecting transformation of CGL.

Long‐term survivors in chronic granulocytic leukaemia: a study by the International CGL Prognosis Study Group

The purpose of the present work were to identify the initial characteristics associated with long-term survival in chronic granulocytic leukaemia (CGL) and to analyse the accuracy of prognostic models in identifying long-term survivors. 813 Philadelphia (Ph) chromosome-positive, nonblastic CGL patients from six American and European institutions, the majority treated conventionally, with a minimum follow-up > 10 years, were studied. Stepwise logistic regression was performed to ascertain the association between the initial clinicohaematological variables and survival > or = 8 years, and a prognostic index was derived. The usefulness of both Sokal's and the new prognostic index to identify long-term survivors was assessed by calculating their positive and negative predictive accuracies, sensitivity and specificity. Median survival of the series was 45 months (range 1-255), with 784 patients (96.4%) having died and 109 (13.4%) surviving 8 years or longer. Younger age, smaller spleen, platelets < or = 600 x 10(9)/l, and lower blood blast percentage were associated with survival > or = 8 years; platelets < or = 600 x 10(9)/l and lower blood blast percentage were the predictive factors in patients 50 years old or younger. Two-thirds of long survivors belonged to Sokal's low-risk group, but the positive predictive accuracy and specificity for prolonged survival of Sokal's index were very low. This was also the case for the new predictive index.(ABSTRACT TRUNCATED AT 250 WORDS)

The maintenance of busulphan-induced remissions in chronic granulocytic leukaemia with recombinant interferon α-2b

Interferon (IFN) shows no specificity in inhibiting the growth of colonies of myeloid leukaemia blasts in culture as compared to normal haemopoietic precursors, but does reduce the self-renewal capacity of myeloblasts. We have tested the ability of IFN to slow the leukocyte doubling time (Ldt) and to prolong remissions induced by busulphan in 14 patients with chronic granulocytic leukaemia (CGL). Patients served as their own controls; the Ldt during relapse from a busulphan-induced remission on no therapy was determined and compared with the Ldt on IFN maintenance therapy. The initial dose of IFN (2 x 10(6) U M-2 subcutaneously, three times per week) was adjusted up, or down, to prevent the leukocyte count from rising and the platelet count from falling below 75 x 10(9) l-1. The dose of IFN required to prevent relapse in seven patients ranged from 1 x 10(6) U M-2 three times per week to 5.2 x 10(6) U M-2 daily, with a median of 2 x 10(6) U M-2 three times per week. IFN maintenance therapy has prevented relapse in six patients for more than 22 months to more than 68 months. In five patients the Ldt was slowed initially but the disease later progressed in four patients to enter the accelerated (three patients) or blast phase (one patient). The Ldt during IFN therapy did not change from the Ldt on no therapy in one patient; this patient later progressed to the blast phase. In two additional patients the leukaemia progressed during the first course of IFN, with shortening of the Ldt; both of these patients entered the blast phase. In the four patients who have discontinued IFN following relapse in the chronic phase, the Ldt remained prolonged for at least one relapse after the IFN was stopped. IFN maintenance therapy failed to control the leukocyte count in the six patients with a control Ldt of less than 40 days and five of these have progressed to enter the accelerated or blast phase. The early survival of this group of patients resembles the survival of 'good risk' CGL patients reported by others. We conclude that IFN maintenance therapy does alter the relapse pattern of a subset of CGL patients, either slowing the Ldt or preventing relapse.

Prediction of impending blast cell transformation in chronic granulocytic leukaemia.

Bone marrow trephine biopsy specimens from 24 patients with chronic granulocytic leukaemia were studied to identify bone marrow changes that suggest incipient or impending blast transformation. In the chronic phase of chronic granulocytic leukaemia, blasts and promyelocytes were seen predominantly in the paratrabecular and perivascular regions, while myelocytes, metamyelocytes and segmented polymorphs were seen predominantly in the central intertrabecular marrow space. The patients were divided into two equal groups according to the degree of perivascular and paratrabecular infiltration: those with minimal (one to three layers of blasts and promyelocytes) and those with marked (four to eight layers of blasts and promyelocytes) infiltration. Ten of the 12 patients in the former group did not develop blast transformation and remained in the chronic phase during a 32- to 84-week follow-up period, whereas nine of the 12 patients in the latter group developed blast transformation, with six undergoing transformation within the first 26 weeks. These findings suggest that the histomorphological pattern of bone marrow changes in chronic granulocytic leukaemia may be useful in recognizing a subset of chronic granulocytic leukaemia patients undergoing blast transformation in the ensuing 6 months.

A Hybrid Eosinophilic–Basophilic Granulocyte in Chronic Granulocytic Leukemia

Morphologic observation of the peripheral blood smear from a patient with chronic granulocytic leukemia suggested the presence of eosinophilic and basophilic granules in the same individual granulocyte. To unambiguously identify eosinophilic and basophilic granules simultaneously in the same preparation, the authors developed a cytochemical staining procedure using basophil-specific toluidine blue and eosinophil-specific cyanide-resistant peroxidase. Using this new dual stain, they demonstrated that ten out of ten chronic granulocytic leukemia patients they examined had cells that contained both eosinophilic and basophilic granules. The identity of the granules was corroborated by electron microscopic studies. These observations suggest that lineage confusion is common in chronic granulocytic leukemia.

Myelofibrosis in chronic granulocytic leukaemia: clinicopathologic correlations and prognostic significance.

We performed 221 marrow trephine biopsies in 139 patients with Ph1-positive (Ph1+) chronic granulocytic leukaemia (CGL) in order to assess the incidence, degree and prognostic significance of marrow fibrosis (MF) at various stages of the disease. We also attempted to elucidate the relationship between development of MF and the various clinical and haematological features of CGL. A significant correlation was found between the amount of fibrosis (graded from 0 to 3) and the stage of CGL, indicating that major fibrotic changes are associated with accelerated or blastic disease. Survival studies performed to assess the prognostic significance of the various degrees of MF, showed a progressively worse life-expectancy from grade 0 to grade 3 fibrosis. Multivariate regression analysis indicated Hb level, age, number of marrow megakaryocytes (MKs), time from diagnosis as the features most significantly correlated with the degree of MF. This study demonstrates that the natural history of CGL involves a progressive increase in reticulin deposition towards severe MF, although the rate of this progression varies widely. Monitoring changes of fibrosis with sequential biopsies could give a measure of the rate of progression of the disease and help in prognostic assessment of CGL patients. Our findings also confirm that among marrow features the number of MKs is the cytological variable most significantly correlated with MF.

Failure of bone marrow cryopreservation in chronic granulocytic leukemia: relation to excessive granulo-macrophagic progenitor pool.

Autologous bone marrow transplantation (ABMT) in chronic granulocytic leukemia (CGL) aims at reversing the acute or acceleration phases by injection of stem cells collected during the chronic phase. This study was designed to explain an unusual rate of delayed engraftment (50%) in our experience of ABMT in CGL patients. We investigated all the factors possibly responsible for abnormal perpetuation of aplasia following infusion of cryopreserved marrow stem cells. The study of CFU-gm recovery in 41 bags of frozen marrow from 25 patients revealed an overall deficiency with a mean CFU-gm recovery of 55 +/- 38% in CGL patients versus 73 +/- 15% in the control group (p less than 0.001). Our data also showed an inverse linear relation (r = -0.40, p less than 0.05) between CFU-gm concentration and recovery after freezing. A good CFU-gm recovery (greater than or equal to = 50%) was observed in 70% of cases when the concentration was less than 3700 CFU-gm/ml as compared to 30% of cases when the concentration was over 3700 CFU-gm/ml (p less than 0.001). The lack of improvement by diluting rich CFU-gm marrows to reduce CFU-gm concentration/ml, as well as the absence of relationship between CFU-gm recovery after freezing and nucleated cells concentration, suggest a particular fragility of CGL stem cells to freezing, probably related to their excessive amplification. At the present time, we strongly recommend that the highest possible dose of progenitor cells be cryopreserved, preferably at a low concentration, in patients with CGL, and particular attention devoted to the freezing procedure in each individual patient, with numerous appropriate efficiency tests.

Antigenic characteristics of circulating CFU-GM in chronic granulocytic leukaemia resemble those of CFU-GM in normal marrow and differ from those in normal blood

We studied the surface antigenic determinants of myeloid progenitor cells (Day 7 CFU-GM, Day 14 CFU-GM and BFU-E) in the peripheral blood and bone marrow of patients with chronic granulocytic leukaemia (CGL) and normal subjects by complement-mediated cytotoxicity with a panel of 8 selected murine monoclonal antibodies (McAbs) folowed by culture in methyl cellulose. All classes of progenitor cell studied expressed HLA-DR antigens and also expressed other antigens recognized by two of the McAbs (S3–13 and S17–25) with myeloid specificity. Two other McAbs (R1.B19 and WGHS.29.1) Recognized antigens on Day 14 CFU-GM derived from normal marrow but not on those from normal blood. The pattern of reactivity of Day 14 CFU-GM from the blood of patients with CGL resembled to a considerable extent that of CFU-GM from normal marrow and differed from that of CFU-GM from normal blood. BFU-E from the blood of patients with CGL reacted with these McAbs in a manner very similar to that of BFU-E from normal blood; however the same two McAbs (R1.B19 and WGHS.19.1) reacted with a much higher proportion of the BFU-E from the marrows of CGL patients than of normal subjects. Our data are consistent with the hypothesis that normal blood-derived CFU-GM are more primitive than marrow-derived CFU-GM; however the CFU-GM in the circulation in CGL differ from those in normal blood, perhaps because they reflect overflow from or exchange with a hyperplastic marrow population.

Antigenic expression and proliferative status of multilineage myeloid progenitor cells (CFU-GEMM) in normal individuals and patients with chronic granulocytic leukaemia.

We assayed the number of multilineage myeloid progenitor cells (CFU-GEMM) in the blood and marrow of patients with newly diagnosed chronic granulocytic leukaemia (CGL). The mean number of CFU-GEMM in the blood was increased 600-fold and CFU-GEMM in the marrow was doubled in the CGL patients compared with normal. A complement-fixing monoclonal antibody with HLA-DR specificity inhibited the proliferation of CFU-GEMM from CGL blood to a greater extent than that of comparable cells in normal marrow. Using a hydroxyurea 'suicide' method we found that the proportion of CFU-GEMM in proliferative cycle was higher in CGL blood than in normal marrow. We conclude that (1) CFU-GEMM numbers are greatly increased in the blood of patients with CGL, (2) CFU-GEMM express HLA-DR antigens on their surface, and (3) the apparently increased expression of the antigen on CFU-GEMM from CGL blood in comparison with CFU-GEMM from normal marrow may parallel the relatively higher proportion of CGL CFU-GEMM in cell cycle.

Histamine symptoms and histamine metabolism in chronic granulocytic leukaemia

Histamine metabolism was investigated in three patients with chronic granulocytic leukaemia (CGL) during symptoms suspected to be caused by histamine release. Plasma histamine levels were excessively high compared with periods when the patients were symptomless or with CGL patients without such symptoms. The patients seemed to be adapted to high plasma histamine levels as the symptoms were not typically systemic in nature, but rather localized phenomena like oedema and pruritus in the extremities. Also CGL patients without symptoms showed abnormally high plasma histamine concentrations, which were significantly related to the whole blood histamine concentration. The possibility must be considered that part of the plasma histamine increase is artificial due to rupture of the basophils during the blood collection procedure.

Generation of CFU-C suppressor T cells in vitro. III. Failure of mitogen-primed T cells from patients with chronic granulocytic leukemia to inhibit the growth of normal CFU-C

T lymphocytes were derived by E rosetting from the peripheral blood (PB) and bone marrow (BM) of 15 patients with chronic granulocytic leukemia (CGL) in the chronic phase of their disease. T cells were also obtained from 12 healthy individuals. T cells were incubated overnight either in culture medium (RPMI) or RPMI plus pokeweed mitogen (PWM). The supernatants were then recovered and the cells washed in fresh RPMI. T cells from normal donors and from CGL patients were then cocultured with normal allogeneic marrow cells grown in soft agar for CFU-C colony formation. Target marrow cells were also grown in agar in the presence of T-derived supernatants. The results of this study can be summarized as follows. (1) Normal PB and BM T cells efficiently suppressed autologous and allogeneic CFU-C growth after PWM stimulation. (2) T cells derived from peripheral blood or marrow of CGL patients failed to inhibit CFU-C growth, whether pretreated with PWM or not. (3) The supernatants of PWM-treated normal T cells strongly inhibited CFU-C colony formation, whereas the supernatants of PWM-treated CGL T cells had no CFU-C/suppressor activity. These data indicate that T cells from CGL patients cannot be primed to become CFU-C suppressor cells after PWM: stimulation in vitro and cannot release a soluble inhibitor of granulopoiesis produced by PWM-primed normal T cells.

Generation of CFU-C suppressor T cells in vitro. III. Failure of mitogen-primed T cells from patients with chronic granulocytic leukemia to inhibit the growth of normal CFU-C

AbstractT lymphocytes were derived by E rosetting from the peripheral blood (PB) and bone marrow (BM) of 15 patients with chronic granulocytic leukemia (CGL) in the chronic phase of their disease. T cells were also obtained from 12 healthy individuals. T cells were incubated overnight either in culture medium (RPMI) or RPMI plus pokeweed mitogen (PWM). The supernatants were then recovered and the cells washed in fresh RPMI. T cells from normal donors and from CGL patients were then cocultured with normal allogeneic marrow cells grown in soft agar for CFU-C colony formation. Target marrow cells were also grown in agar in the presence of T-derived supernatants. The results of this study can be summarized as follows. (1) Normal PB and BM T cells efficiently suppressed autologous and allogeneic CFU-C growth after PWM stimulation. (2) T cells derived from peripheral blood or marrow of CGL patients failed to inhibit CFU-C growth, whether pretreated with PWM or not. (3) The supernatants of PWM-treated normal T cells strongly inhibited CFU-C colony formation, whereas the supernatants of PWM- treated CGL T cells had no CFU-C/suppressor activity. These data indicate that T cells from CGL patients cannot be primed to become CFU- C suppressor cells after PWM: stimulation in vitro and cannot release a soluble inhibitor of granulopoiesis produced by PWM-primed normal T cells.

GM-CFC growth in chronic granulocytic leukaemia is not affected by a soluble inhibitor released by aplastic anaemia T-cells or mitogen-primed normal T-lymphocytes.

Peripheral blood (PB) and bone marrow (BM) cells were obtained from 12 patients with chronic granulocytic leukaemia (CGL) and cultured in agar for granulocyte macrophage colony formation (GM-CFC). In addition PB and BM CGL cells were co-cultured with T-lymphocytes from patients with immune severe aplastic anaemia (SAA), or with T-cells from healthy donors primed with pokeweed mitogen (PWM). The supernatants of SAA and PWM primed T-cells were also added to CGL cells grown in agar. Normal marrow cells obtained from eight healthy donors were used to set up control cultures and co-cultures. The results of this study indicate that, firstly, T-cells derived from SAA patients and their supernatants suppress GM-CFC growth of normal marrow cells but not of PB nor BM CGL cells, and, secondly, normal T-cells primed with PWM and their supernatants suppress normal marrow GM-CFC but not colony formation of BM nor PB CGL cells. These results provide further evidence that mediators which are effective in regulating normal myeloid progenitor cells fail to inhibit the in vitro growth of GM-CFC from CGL patients.