RESUMO
OBJECTIVE: To investigate the quantities of bone marrow CD5+ B lymphocytes in the patients with autoimmune hemocytopenia and the relationship between quantities of CD5+ B lymphocytes and clinical or laboratorial parameters. METHODS: Quantities of CD5+ B lymphocytes in the bone marrow of 14 patients with autoimmune hemolytic anemia (AIHA) or Evans syndrome, 22 immunorelated pancytopenia (IRP) patients, and 10 normal controls were assayed by flow cytometry. The correlation between their clinical or laboratorial parameters and CD5+ B lymphocytes was analyzed. RESULTS: The quantity of CD5+ B lymphocytes of AIHA/Evans syndrome (34.64% +/- 19.81%) or IRP patients (35.81% +/- 16.83%) was significantly higher than that of normal controls (12.00% +/- 1.97%, P < 0.05). However, there was no significant difference between AIHA/Evans syndrome and IRP patients (P > 0.05). In all hemocytopenic patients, the quantity of bone marrow CD5+ B lymphocytes showed significantly negative correlation with serum complement C3 level (r = -0.416, P < 0.05). In the patients with AIHA/Evans syndrome, the quantity of bone marrow CD5+ B lymphocytes showed significantly positive correlation with serum indirect bilirubin level (r = 1.00, P < 0.05). In Evans syndrome patients, the quantity of CD5+ B lymphocytes in bone marrow showed significantly positive correlation with platelet-associated immunoglobulin G (r = 0.761, P < 0.05) and platelet-associated immunoglobulin M ( r = 0.925, P < 0.05). The quantity of CD5+ B lymphocytes in bone marrow of all hemocytopenic patients showed significantly negative correlation with treatment response (tau-b = -0.289, P < 0.05) , but had no correlation with colony forming unit-erythroid (r = -0.205, P > 0.05) or colony forming unit-granulocyte-macrophage colonies (r = -0.214, P > 0.05). CONCLUSIONS: The quantity of bone marrow CD5+ B lymphocytes in the patients with autoimmune hemocytopenia significantly increases and is correlated with disease severity and clinical response, which suggest that CD5+ B lymphocytes might play an important role in the pathogenesis of autoimmune hemocytopenia.
Assuntos
Anemia Hemolítica Autoimune/imunologia , Doenças Autoimunes/imunologia , Linfócitos B/classificação , Linfócitos B/imunologia , Anemia Hemolítica Autoimune/tratamento farmacológico , Doenças Autoimunes/tratamento farmacológico , Ciclosporina/uso terapêutico , Quimioterapia Combinada , Citometria de Fluxo , Glucocorticoides/uso terapêutico , HumanosRESUMO
BACKGROUND: Polycythemia vera (PV) is a malignant disorder of hemaopoietic stem cells which is characterized by clonal hyperproliferation and a low rate of apoptosis. This study was to assess endogenous erythroid colony (EEC) formation in the bone marrow of PV patients and determine its clinical significance. METHODS: The bone marrow mononuclear cells of 26 patients with PV, 2 patients with secondary erythrocytosis (SE), and 19 normal controls were cultured by Marsh's method for EEC evaluation, and the clinical significance was evaluated. RESULTS: EECs appeared in 25 patients with PV but not in 2 patients with SE and 19 normal controls. The number of EECs and the EEC ratio [EEC/erythropoietin (EPO)-dependent colony forming unit-erythroid (CFU-E)] in PV patients positively correlated with hemoglobin (Hb) levels. Their EEC number did not correlate with white blood cell (WBC) counts, platelet (PLT) counts, or leukocyte alkaline phosphatase (LAP) scores. Their EEC did not correlate with serum EPO levels. Fifteen patients with PV were treated with hydroxyurea (Hu) and/or interferon-alpha (IFN-alpha). Their EEC ratio before treatment positively correlated with the treatment time required for complete remission (CR) and negatively correlated with the time before relapse. The EEC numbers of 7 PV patients treated with Hu/IFN-alpha decreased after the blood cell counts dropped to normal levels. There was a positive correlation between the EEC ratio and the incidence of attacks of vascular thrombosis in PV patients. The numbers of apoptosised bone marrow mononuclear cells in PV patients were lower than those in normal controls. The EEC numbers of PV patients negatively correlated with the rate of apoptosis of bone marrow mononuclear cells. CONCLUSIONS: EEC formation is characteristic in PV patients. EEC number in PV patients positively correlates with Hb levels, the time required for CR, and the incidence of attacks of vascular thrombosis. EEC number negatively correlates with the time before relapse. Bone marrow suppressive treatment might decrease EEC number. Thus, EEC number is a sensitive and specific parameter reflecting the abnormal hematopoietic clone burden induced by polycythemia vera. EEC number is an important diagnostic parameter for PV patients.
Assuntos
Células Precursoras Eritroides/fisiologia , Eritropoese , Policitemia Vera/sangue , Adulto , Idoso , Apoptose , Ensaio de Unidades Formadoras de Colônias , Eritropoetina/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Policitemia Vera/terapia , Trombose/epidemiologiaRESUMO
OBJECTIVE: To analyse the proportion of hepatitis associated aplastic anemia (HAAA) in severe aplastic anemia (SAA) and its clinical features of HAAA. METHODS: All newly diagnosed SAA cases in our department in the recent 5 years were analyzed. A case-control study was undertaken to investigate the differences of clinical and laboratory features between HAAA and non-hepatitis associated SAA (non-HASAA) patients. RESULTS: The proportion of HAAA in SAA was 3.3%. There was no significant difference in PB cell counts, bone marrow hematopoiesis status and the amount of blood transfusion between HAAA and non-HASAA patients. Sera from 13 patients with HAAA were tested for antibodies to hepatitis viruses A, B, and C and hepatitis B surface antigen. Twelve (92.3%) of them had negative serologic results for the tests and only one (7.7%) had a positive result for HBsAg and HBeAg. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were decreased prior to the diagnosis in twelve (92.3%) of the 13 HAAA patients. The percentage of CD4(+) cells in HAAA patients was significantly lower than that in non-HASAA patients (P < 0.05). HAAA patients had higher percentages of CD8(+) cells (P < 0.05) and lower ratios of CD4(+)/CD8(+) (P < 0.05). The early infection rate of the HAAA patients was significantly higher than that of non-HASAA patients (84.6% vs 42.3%, P < 0.05), with different mortalities (61.5% vs 15.4%, P < 0.05). The 2-year survival rate of HAAA patients was significantly lower than that of non-HASAA patients (16.6% vs 83.2%, P < 0.01). CONCLUSION: The proportion of HAAA in SAA was 3.3%. Most of HAAA were associated with non-A, non-B and non-C hepatitis virus. Compared with that of non-HASAA, the abnormality of T cell immunity of HAAA was more severe, with a higher frequency of early infection and a higher mortality rate.
Assuntos
Anemia Aplástica/patologia , Hepatite Viral Humana/complicações , Adolescente , Adulto , Anemia Aplástica/sangue , Anemia Aplástica/complicações , Estudos de Casos e Controles , Feminino , Seguimentos , Hepacivirus/imunologia , Anticorpos Anti-Hepatite A/sangue , Vírus da Hepatite A/imunologia , Anticorpos Anti-Hepatite B/sangue , Vírus da Hepatite B/imunologia , Anticorpos Anti-Hepatite C/sangue , Hepatite Viral Humana/sangue , Hepatite Viral Humana/virologia , Humanos , MasculinoRESUMO
OBJECTIVE: To study the quantity and ratio of Th1, Th2 cells in the bone marrow of myelodysplastic syndromes (MDS) patients, and to evaluate the correlation between the ratio of the blast cells and the number of the Th1 cells in the bone marrow of MDS patients. METHODS: By FACS, the quantity and ratio of IFN-gamma producing CD4(+) T cell (Th1) and IL-4 producing CD4(+) T cell (Th2) cells in the bone marrow were detected in 21 MDS patients, 18 normal controls and 13 severe aplastic anemia (SAA) patients respectively. The karyotypes of 18 MDS patients and 15 normal controls were assayed. The correlation between the ratio of the blast cells in the bone marrow and the number of the Th1 cells in the MDS patients were analyzed. RESULTS: The percentages of Th1 cells, Th2 cells and ratio of Th1/Th2 in the bone marrow of normal controls were (0.48 +/- 0.10)%, (0.24 +/- 0.19)% and 2.31 +/- 0.76 respectively, while those of the MDS patients were (0.36 +/- 0.11)%, (0.76 +/- 0.35)% and 0.51 +/- 0.13. The percentage of Th1 cells of patients with MDS was reduced and the Th1/Th2 ratio was significantly lower than that of normal controls (P < 0.01). Those of the patients with SAA were (4.75 +/- 0.49)%, (0.40 +/- 0.28)% and 26.5 +/- 8.79 respectively, their Th1 cells and Th1/Th2 ratio were markedly higher than those of normal controls (P < 0.01). In all of the 15 normal controls the karyotypes were normal, but that of MDS patients was (50.00 +/- 0.10)%. The lower ratio of the Th1 cells in the bone marrow of the patients with MDS and the AML which progressed from MDS was negatively correlated with the higher percentage of the blast cells (r = -0.563, P < 0.01). CONCLUSIONS: (1) The immune function of T lymphocytes in MDS is abnormal: the balance between Th1 and Th2 cells is broken. (2) With descending of the number of Th1 cells in the bone marrow of the MDS patients, the disease is progressing to leukemia.
Assuntos
Medula Óssea/imunologia , Síndromes Mielodisplásicas/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Adulto , Idoso , Feminino , Humanos , Cariotipagem , Masculino , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/genéticaRESUMO
OBJECTIVE: To explore the effect of T(3) on the expression of transferrin receptor (TfR) and ferritin (Fn) in K562 cells and its possible mechanism. METHODS: Flow cytometry was used for the detection of TfR expression, radioimmunoassay for Fn expression, RNA/protein band shift assay for the binding activity of iron regulatory protein (IRP) and iron responsive elements (IRE), and RT-PCR for TfR and Fn mRNA levels. RESULTS: Different concentration of T(3) significantly increased Fn expression of K562 cells, especially at 100 nmol/L and 200 nmol/L (p < 0.05). However, T(3) had no effect on TfR expression. T(3) decreased the binding activity between IRP and IRE, particularly at concentration of 50 nmol/L. Different concentration of T(3) increased Fn-H mRNA level at different time point while it had no effect on TfR mRNA level. CONCLUSION: T(3) increased Fn expression of K562 cells through the possible mechanisms of either the post-transcriptional regulation or transcriptional modulation.
Assuntos
Ferritinas/biossíntese , Receptores da Transferrina/biossíntese , Tri-Iodotironina/farmacologia , Ferritinas/efeitos dos fármacos , Ferritinas/genética , Citometria de Fluxo , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Humanos , Células K562 , RNA Mensageiro/genética , Radioimunoensaio , Receptores da Transferrina/efeitos dos fármacos , Receptores da Transferrina/genética , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
OBJECTIVE: To study the apoptosis and proliferation of CD(34) positive (CD(34)(+)) bone marrow cells (BMC) in patients with polycythemia vera (PV). METHODS: The expression of Annexin V and Ki67 of the CD(34)(+) BMC in 20 PV patients and control cases [10 essential thrombocythemia (ET), 12 normal persons] were assessed by bicolor flow cytometry (FCM), and the correlation between apoptosis and clinical situation was analysed in PV patients. RESULTS: The Annexin V expressions of CD(34)(+) BMC were (15.96 +/- 1.45)% in PV patients and (15.53 +/- 1.76)% in ET patients which were lower than that in normal subjects [(23.61 +/- 3.89)%, (P < 0.05)]. The Ki67 expression of CD(34)(+) BMC was (48.79 +/- 11.68)% in PV patients and (49.60 +/- 9.98)% in ET patients, which were significantly higher than that in normal controls (33.87 +/- 6.82)%. The ratio of apoptosis/proliferation in PV patients was 0.33 +/- 0.10 and in ET patients 0.32 +/- 0.02 which were significantly lower than that in normal controls 0.72 +/- 0.11 (P < 0.01). The apoptosis of CD(34)(+) BMC was negatively correlated with the hemoglobin (Hb) levels (r = -0.481, P = 0.037), white blood cells (WBC) (r = -0.538, P = 0.026) and the numbers of endogenous erythroid colony (EEC) (r = -0.632, P = 0.50), and the ratio of apoptosis/proliferation was negatively correlated with the Hb (r = -0.537, P = 0.018) and WBC (r = -0.667, P = 0.003) in PV patients. CONCLUSION: There were lower apoptosis and higher proliferation in CD(34)(+) BMC of PV patients. Lower apoptosis was correlated with the severity of the disease.
Assuntos
Antígenos CD34/análise , Apoptose , Células da Medula Óssea/citologia , Policitemia Vera/patologia , Adulto , Anexina A5/análise , Divisão Celular , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
OBJECTIVES: To explore the proliferative capacity of bone marrow hematopoietic stem cells and the function of T helper (Th) lymphocytes of patients with immuno-related pancytopenia (IRP). METHODS: Twenty-five untreated IRP patients, 15 IRP patients in complete remission (CR) and 10 normal controls were studied for in vitro yields of CFU-GM, CFU-E and BFU-E from bone marrow mononuclear cells (BMMNC). The mRNA expressions of IL-4, IL-10, IFN-gamma and IL-2 genes in unstimulated BMMNC from 25 untreated IRP patients,15 IRP patients in CR, 19 patients with other hematological diseases presenting pancytopenia and 10 normal controls were detected by reverse transcription polymerase chain reaction (RT-PCR). RESULTS: There was no significant difference of the yields of CFU-E, CFU-GM or BFU-E among the untreated, and in CR IRP patients and normal controls (P > 0.05). The mRNA expressions of IL-4 and IL-10 of Th2 cells were significantly higher in untreated IRP patients than in the other groups. The mRNA expressions of IFN-gamma and IL-2 of the Th1 cells in all IRP patients were not higher than those in the other groups. CONCLUSIONS: The cytopenia of IRP patients was not caused by the qualitative abnormality of the hematopoietic stem cells but by the destruction or suppression of hematopoietic stem cells from certain extrinsic insults. The imbalance of Th lymphocytes subtypes and overfunction of Th2 lymphocytes played important roles in the pathogenetic mechanism of IRP leading to increased and overfunctional B lymphocytes, which produced autoantibodies destructing or suppressing hematopoiesis in IRP.
Assuntos
Células da Medula Óssea/citologia , Células-Tronco Hematopoéticas/citologia , Pancitopenia/imunologia , Linfócitos T Auxiliares-Indutores/fisiologia , Adolescente , Adulto , Divisão Celular , Células Cultivadas , Criança , Citocinas/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , RNA Mensageiro/análiseRESUMO
OBJECTIVE: To evaluate the quantitative and functional changes of T helper (Th) cell subsets in the bone marrow of severe aplastic anemia (SAA) patients and the relationship between these changes and the patients hematopoietic function. METHODS: By FACS, the quantity and ratio of Th1 and Th2 cells, the percentage of CD3(+)CD8(+) cells in the bone marrow were detected in 24 patients with SAA at active phase, 15 patients with SAA at recovery phase, and 16 normal controls. By radioimmunoassay, the serum levels of TNF-alpha, or IL-4 in 20 SAA patients at active phase, 12 at recovery phase and 16 normal controls were measured. The relationships between CD3(+)CD8(+) cells, TNF-alpha and Ret, ANC; and between Th1 cells and CD3(+)CD8(+) cells, TNF-alpha or Ret, ANC; between IL-4, balance of Th1/Th2 and Ret, ANC were evaluated. RESULTS: The percentages of Th1 and Th2 cells, and ratio of Th1/Th2 in bone marrow of SAA patients at active phase were (4.87 +/- 2.64)%, (0.41 +/- 0.26)% and 21.22 +/- 5.07, respectively, being higher than those of normal controls [(0.42 +/- 0.30)% (P < 0.01), (0.24 +/- 0.17)% (P < 0.05) and (1.57 +/- 0.93) (P < 0.01), respectively] and all of them reduced to normal levels of SAA at recovery phase (P > 0.05). The percentage of CD3(+)CD8(+) cells significantly decreased from (32.32 +/- 8.69)% at active phase to (13.76 +/- 2.96)% at recovery phase (P < 0.01). The serum levels of TNF-alpha and IL-4 at active phase was (4.29 +/- 3.15) microg/L and (1.24 +/- 0.73) microg/L, respectively, being higher than those of normal controls (1.21 +/- 1.16) microg/L, (1.18 +/- 0.97) microg/L, but only the difference of TNF-alpha was statistically significant (P < 0.01). In recovery SAA patients, the serum levels of TNF-alpha significantly decreased to (1.46 +/- 1.41) microg/L (P < 0.01), and the levels of IL-4 increased markedly to (3.05 +/- 1.94) microg/L. The CD3(+)CD8(+) cells and TNF-alpha of patients negatively correlated with Ret (P < 0.05; P < 0.05) and ANC (P < 0.05; P < 0.05), Th1 cells correlated with CD3(+)CD8(+) cells and TNF-alpha positively (P < 0.01; P < 0.05), the Ret and ANC negatively (P < 0.01; P < 0.01), IL-4 and the balance of Th1/Th2 positively correlated with Ret and ANC (P < 0.05, P < 0.01; P < 0.01, P < 0.01). CONCLUSION: The bone marrow failure in SAA might be caused not only by the increase of Th1 cells, Th1 type effector cells and cytokines, but also by insufficient compensation of Th2 cells and Th2 type cytokines, which shifted the balance of Th1/Th2 favorable to Th1.
Assuntos
Anemia Aplástica/patologia , Medula Óssea/patologia , Linfócitos T Auxiliares-Indutores/patologia , Adolescente , Adulto , Anemia Aplástica/sangue , Anemia Aplástica/fisiopatologia , Medula Óssea/metabolismo , Complexo CD3/sangue , Antígenos CD8/sangue , Criança , Feminino , Sistema Hematopoético/metabolismo , Sistema Hematopoético/patologia , Sistema Hematopoético/fisiopatologia , Humanos , Interleucina-4/sangue , Masculino , Pessoa de Meia-Idade , Radioimunoensaio , Linfócitos T Auxiliares-Indutores/metabolismo , Células Th1/metabolismo , Células Th1/patologia , Células Th2/metabolismo , Células Th2/patologia , Fator de Necrose Tumoral alfa/sangue , Adulto JovemRESUMO
OBJECTIVE: To investigate the expression of apoptosis receptor FAS (CD95) and apoptosis related protein Bcl-2 and Bax in CD34 positive bone marrow cells of the patients with polycythemia vera (PV). METHODS: The expressions of apoptosis receptor FAS (CD95) and apoptosis related protein Bcl-2 and Bax in bone marrow CD34(+) cells from 21 PV patients, 8 essential thrombocythemia (ET) and 11 normal persons were assessed by bicolor flow cytometry (FCM), and the expressions of Bcl-2 and Bax mRNA were assessed by RT-PCR, and their correlation was analysed. RESULTS: There was no difference between the expressions of CD95 in CD34(+) bone marrow cells of PV patients (42.65 +/- 15.56)%, and that of ET patients (45.31 +/- 17.62)% and of normal person (37.55 +/- 15.19)% (P > 0.05). There was no difference between the expression of Bax in CD34(+) bone marrow cells of PV patients (35.83 +/- 9.33)% and of normal persons (41.65 +/- 9.04)% (P > 0.05). The expression of Bcl-2 in CD34(+) bone marrow cells of PV patients (79.35 +/- 14.43)% was significantly higher than that of normal controls (55.84 +/- 13.43)% (P < 0.01). The ratio of Bax/Bcl-2 of PV patients (0.47 +/- 0.14) was significantly lower than that in normal controls (0.76 +/- 0.24) (P < 0.01). The expression of Bcl-2 mRNA in PV patients' bone marrow hematopoietic cells was higher than that of normal controls (P < 0.01). There was no difference between the expression of Bax mRNA in bone marrow hematopoietic cells of PV patients and that of normal controls. Bcl-2 expression was negatively correlated with Annexin V expression in CD34(+) bone marrow cells of PV patients. CONCLUSION: Over-expression of Bcl-2, one of anti-apoptosis genes, in CD34(+) bone marrow cells might be involved in the lower apoptosis of PV patients.
Assuntos
Antígenos CD34/sangue , Células da Medula Óssea/patologia , Policitemia Vera/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Células da Medula Óssea/metabolismo , Feminino , Citometria de Fluxo , Humanos , Masculino , Pessoa de Meia-Idade , Policitemia Vera/sangue , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Proteína X Associada a bcl-2/sangue , Proteína X Associada a bcl-2/genética , Receptor fas/sangueRESUMO
OBJECTIVE: To study the clinical features of severe aplastic anemia (SAA) patients with complication of infection. METHODS: A retrospective analysis of prevalence of infection occurring in 229 SAA patients, their bacterial spectrum, and the effect of GM-CSF or G-CSF on the infection were done. RESULT: The prevalence of infection in SAA patients was 86.0%, among which 54.2% was infected with gram-positive organisms, 40.0% with gram-negative bacilli and 5.8% with fungal infections. Septicemia occurred mostly with E. coli and Pseudomonas infection. Patient's neutropenia was significantly related to the infection. The patients with neutrophil count less than 0.2 x 10(9)/L had more frequent and severe infection. Age, hemoglobin level, subtype of T lymphocytes and antithymocyte globulin therapy were not related to infection. Prophylaxis usage of floxacin could not reduce patient' gastrointestinal infection. The total mortality of SAA patients with infection was 23.1%. Pulmonary infection and septicemia increased mortality, and GM-CSF/G-CSF therapy reduce mortality. CONCLUSION: SAA patients were at high risk of infection which was significantly associated with severe neutropenia. GM-CSF or G-CSF therapy exerts an assistant role to antibiotics in controlling the infections.
Assuntos
Anemia Aplástica/complicações , Infecções/etiologia , Adolescente , Adulto , Idoso , Antibacterianos/uso terapêutico , Bactérias/isolamento & purificação , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Infecções/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Fatores de TempoRESUMO
OBJECTIVE: To analyse the relapse rate and risk factors of autoimmune hemolytic anemia (AIHA) and Evans syndrome. METHODS: Fifty two cases of AIHA and Evans syndrome in remission being followed up for 1 - 14 years (median time 3.8 years) were analysed for relapse rate. The risk factors of relapse were analysed by case-control study. RESULTS: The total relapse rate of these AIHA and Evans syndrome patients was 57.7%, and the median remission duration to the first relapse was 9 months. The relapse rates in patients with negative Coombs test, warm autoantibodies and both of warm and cold autoantibodies were 30.8% (4/13), 54.0% (13/24) and 86.7% (13/15), respectively. The relapse rate in patients with cold antibody was the highest (P < 0.05). The relapse rate in patients with antibody titer >or= 100 was 92.9% (13/14) and was higher than that in patients with antibody titer < 100 [59.5% (13/22)] (P < 0.05). Patients treated with prednisone and cyclosporin relapsed less than those treated with prednisone alone, and the relapse was related to the therapy course of prednisone and CsA. CONCLUSION: Because of the high relapse rate, AIHA and Evans syndrome should be treated according to the class of autoantibodies, and with longer course of prednisone and cyclosporin and prophylaxis of infection.
Assuntos
Anemia Hemolítica Autoimune/etiologia , Trombocitopenia/etiologia , Adolescente , Adulto , Idoso , Anemia Hemolítica Autoimune/imunologia , Autoanticorpos/sangue , Criança , Ciclosporina/uso terapêutico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prednisona/uso terapêutico , Recidiva , Fatores de Risco , Síndrome , Trombocitopenia/imunologiaRESUMO
OBJECTIVE: To investigate the growth of endogenous erythroid colony (EEC) in polycythemia vera (PV) patients and its clinical significance. METHODS: Bone marrow mononuclear cells of 26 PV patients, 2 secondary erythrocytosis (SE) and 19 normal controls were cultured by Marsh's method for EEC. RESULTS: 1. EEC was present in 25/26 (96.2%) PV patients and was not found in 2 SE patients and 19 normal controls. 2. The number of EEC and the ratio of EEC/Epo-dependent CFU-E (EEC ratio) were positively correlated with the hemoglobin (Hb) levels (r = 0.608, P = 0.01) in PV patients, but did not correlate with white blood cell (WBC) counts, platelet counts and neutrophil alkaline phosphatase scores. 3. EEC did not correlate with PV patients' serum Epo levels (r = 0.518, P = 0.125). 4. Fifteen PV patients were treated with hydroxyurea and/or interferon-alpha. Their EEC ratio before treatment was correlated positively with the time required for complete remission (CR) (r = 0.651, P = 0.009) and negatively with the time before relapsing (r = -0.529, P < 0.02). 5. EECs of 7 PV patients treated with HU/IFN were decreased after their blood cell counts normalization. 6. There was a positive correlation between the EEC ratio and the attacks of vascular thrombosis (r = 0.524, P = 0.01). (7) The apoptosis of bone marrow mononuclear cells of PV patients was less than that of normal controls. PV patients' EEC was negatively correlated with the apoptosis of their bone marrow mononuclear cells (r = -0.192, P < 0.045). CONCLUSION: EEC is peculiarly present in PV patients, and is a sensitive parameter in reflecting the abnormal hematopoietic clone burden and in diagnosing and monitoring the disease.