Original research paper
Impact of serum adiponectin and leptin levels in acute leukemia Salah Aref1 , Lamiaa Ibrahim1, Emad Azmy 2, Rasha Al Ashary 3 1
Hematology Unit, Clinical Pathology Department, Mansoura, Egypt, 2Hematology Unit, Mansoura Cancer Institute, Mansoura, Egypt, 3Pediatric Hematology Oncology Department, Mansoura Faculty of Medicine, Mansoura, Egypt Adipocytokines was stated to exert biological effect on tumor cells. Two adipokines, leptin and adiponectin in particular, have come to be recognized for their influence on tumor biology including leukemia. The prognostic effect of leptin and adiponectin concentrations in acute leukemia patients remains to be identified. This study was conducted on 80 acute leukemia patients: 35 acute myeloid leukemia (AML), 45 acute lymphoid leukemia (ALL), and 20 controls of matched age and sex. Leptin and adiponectin were assayed by enzyme-linked immunosorbent assay at diagnosis. Serum leptin levels were significantly higher in ALL patients, and significantly lower in AML patients when compared with normal controls (P = 0.01, P = 0.04 respectively). On the other hand, serum adiponectin levels were significantly lower in AML and ALL patients as compared with normal controls (P = 0.00 for both). No significant differences exist regarding body mass index between acute leukemia patients and normal controls (P > 0.05). Correlation studies revealed that there were significant negative correlations between serum adiponectin levels and bone marrow (BM) blast cells and serum lactic dehydrogenase (sLDH) in acute leukemia groups (r 0.542, P < 0.01, r 0.699, P < 0.001, respectively). Regarding serum leptin levels there were positive significant correlations with BM blast cells (r 0.74, P < 0.01), total WBC counts (r = 0.59, P < 0.05), sLDH (r 0.738, P < 0.01) in ALL group; and significant negative correlations with BM blast cells (r 0.542, P < 0.01) and sLDH in the AML group. Adipocytokines may represent a new non-invasive biomarker in acute leukemia patients. Estimation of adiponectin and leptin serum levels at acute leukemia diagnosis could also be considered as a prognostic marker, which will be used in acute leukemia stratification. Keywords: Adiponectin, Leptin, Prognosis, AML, ALL
Introduction Acute leukemia is characterized by clonal proliferation of the hematopoietic progenitor cells and accumulation of immature cells. The overall long-term free survival after intensive chemotherapy is less than 50%, but the prognosis can be improved by allogeneic stem cell transplantation for subsets of younger patients. The further investigation of these new treatment strategies will require detailed knowledge about the regulation of leukemic hematopoiesis by the cytokine network in the bone marrow (BM).1 Both leukemia and its treatment can have a severe catabolic effect. Even, when well and in remission patients with cancer are severely catabolic even in remission state.2 Adipokines are a group of novel and highly active molecules that are abundantly secreted by adipocytes, Correspondence to: Dr Salah Aref, Hematology Unit, Clinical Pathology Department, Mansoura Faculty of Medicine, Mansoura, Egypt. Email:
[email protected]
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© W. S. Maney & Son Ltd 2013 DOI 10.1179/1607845412Y.0000000059
and act at both the local and systemic levels. They have attracted considerable interest due to their potential role in the development of cancer as a risk factor. Adipokines have been shown to regulate the survival, proliferation, differentiation and function of normal hematopoietic and leukemic cells.3 Two adipokines, leptin and adiponectin in particular, have come to be recognized for their influence on tumor biology.4 Leptin is a 16-kDa peptide hormone predominantly produced by white adipose tissue. The main function of leptin in the human body is the regulation of energy expenditure and control of appetite. Serum level of leptin reflects the amount of energy stored in the adipose tissue and is in proportion to body fat mass.5 Leptin appears to play an important role in immunity and hematopoiesis. Leptin exerts proliferative, anti-apoptotic, and differentiating effects on hematopoietic neoplastic cells. Marrow adipocytes are a significant source of leptin in the BM.6 Leptin induces its action through receptors, which was reported to
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be expressed in leukemic cells from patients with acute myeloblastic leukemia (AML), higher expression in blast crisis than chronic phase in CML were reported. They are expressed weakly in acute lymphoid leukemia (ALL) blasts, but not in CLL cells.7 Adiponectin, an adipocyte-derived secretory protein, is a 30-kDa complement C1q-related protein. Adiponectin circulates as several multimeric species, including a high molecular weight form thought to be the most clinically relevant. Serum levels of adiponectin are markedly decreased in individuals with visceral obesity and states of insulin resistance, such as type 2 diabetes mellitus and atherosclerosis.8 In addition to the relations between adipocytokines and obesity or diabetes, numerous other functions of these hormones in the human body have been identified, including potential roles in the regulation of inflammation, angiogenesis and tumor growth. Disturbances in the production of adipocyte-derived hormones may thus represent a new link explaining the well-known association between obesity and increased the prevalence of malignancies.9 The aim of the current study is to assess the levels of leptin and adiponectin in acute leukemia, and to assess their prognostic roles.
Patients and methods The present study was conducted on 80 patients with untreated acute leukemia (60 males and 40 females), age ranged from 33 to 75 years, and 20 controls of matched age and sex. They were recruited from Mansoura Oncology Center. The study was approved by the research ethics committee and consents were obtained from patients in the study. Group I: Includes 35 patients with ALL before start of therapy Group II: Includes 45 AML patients before start of therapy Group III: Includes 20 healthy controls of matched age and sex. • Patients with febrile neutropenia, sepsis, any organ failure, with hypertension or diabetes were excluded. • Body mass index (BMI) was calculated by dividing body weight (kg) by square height (m2). We dichotomized BMI as BMI < 25 (non-overweight and nonobese) and BMI > 25 (overweight and obese).
Specimen collection: • Blood samples were collected for complete blood count (1 cm EDTA) from three groups. • Blood were collected from group I and group II (2 cm EDTA) for immunophenotyping using flow cytometry. • Two milliliters serum samples were collected for serum leptin, adiponectin, and serum lactic dehydrogenase (sLDH) estimation from the three studied groups. Blood samples were obtained after an overnight fast.
Impact of serum adiponectin and leptin levels in acute leukemia
All patients were subjected at presentation to a full clinical history and physical examination and the following laboratory investigations: • Complete blood counts (CBCs). • BM aspirate • Immunophenotyping was done using EPICS XL flow cytometer (Coulter Electronics, Hialeah, FL, USA). Panel included T-cell markers (CD1, CD3, CD4, CD5, CD7, CD8), B-cell markers (CD10, CD19, CD22, CD34, cytoplasmic u), and myeloid markers (MPO, CD13, CD33, HLA-DR).
Cytogenetic analysis Pretreatment cytogenetic analyses of BM or peripheral blood (PB) were performed. Metaphases chromosomes were banded by G-banding technique and Karyotyped according to the International System for Human Cytogenetic Nomenclature. A minimum of 20 metaphases was required to be examined for a patient to be classified as having normal cytogenetic. Leptin assay DRG® Leptin (Sandwich) ELISA (EIA-2395) (R&D Systems, Minneapolis, MN, USA): The DRG Leptin ELISA kit is a solid-phase enzyme-linked immunosorbent assay (ELISA) based on the sandwich principle. The micro titer wells are coated with a monoclonal antibody directed towards a unique antigenic site on a leptin molecule. The intensity of color developed is proportional to the concentration of leptin in the sample. The concentration of the samples can be read directly from standard curve. Adiponectin assay R&D Quantikine Human Total Adiponectin/Acrp30 Immunoassay (DRP300) (R&D Systems). Quantitative sandwich enzyme immunoassay technique. The concentration of the samples can be read directly from standard curve.
SLDH ezyme assay SLDH were determined on the day of admission or before start of chemotherapy was started in all acute leukemia patients. SLDH levels were determined using kits obtained from Biomerieux S.A. Marcy L’ toile, France.
Statistical analysis The statistical analysis of data was performed by using excel program and SPSS version 16 (statistical package for social science). Qualitative data were described in the form of numbers and percentages. Quantitative data were described in the form of mean (±) standard deviation (SD). Statistical analysis was performed by comparison between groups using chi-square test regarding qualitative data while quantitative non-parametric data comparison was performed
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Impact of serum adiponectin and leptin levels in acute leukemia
using one-way analysis of variance and paired sample t-test. The probability of being by chance (P value) was calculated for all parameters (P is significant if < or =0.05 at confidence interval 95%).
Results Hemoglobin and platelet counts were significantly lower and white cell count was significantly higher in acute leukemia patients as compared with controls (P = 0.00) (Table 1). According to cytogenetic findings, the acute leukemia group was classified into three risky subgroups: favorable, intermediate, and unfavorable one. While the serum leptin levels were higher in the unfavorable group, followed by intermediate and the lowest levels in the favorable subgroup, the adiponectin levels were significantly higher in favorable subgroup followed by intermediate and lowest levels in the Table 1
Acute leukemia patient’s characteristics
Age (year) Sex Male Female Pallor Bleeding tendency Splenomegaly Hepatomegaly Lymphoadenopathy WBCs × 103 (cmm) HB (g/dl) Platelets (109/l) BM blasts (%) FAB classification (number)
Cytogenetic Normal Favorable t(8;21)(q22;q22) Inv16 t (16,16) t(12,21) Intermediate t(9;11)(p22;q23)-MLLT3-MLL Unfavorable t(v;11)(v;q23)-MLL rearrangement t(9,22) t(8;14)(q24.1;q32) Immunophenotyping B lineage (CD 19, 20, 22) T lineage (CD 2, 7,3) Myeloid lineage (CD 13, 33, MPO)
Table 2
ALL n = 45
AML n = 35
42.8 ± 12.9 (19–60)
49.1 ± 12.9 (20.0–73.0)
34 (75.5%) 11 (24.5%) 12 (26.6%) 15 (33.3%) 20 (44.5%) 22 (48.8%) 16 (35.5 %) 87.6 ± 25.8 (32.9–167.0) 8.6 ± 1.4 (6.5–11.5) 90.08 ± 149.2 (5.3–675) 75.0 ± 19.2 (35.0–100.0) L1 15 L2 22 L3 8
21 (61.7%) 14 (38.3%) 15 (42.8%) 20 (57.1%) 25 (71.4%) 27 (77.1%) 12 (34.3%) 80.4 ± 21.1 (37.8–193.0) 8.3 ± 2.0 (5.1–13.7) 50.8 ± 32.2 (7.0–119.0) 65.1 ± 22.3 (10.0–90.0) M1 3 M2 9 M4 12 M5 7 M6 4
17/45
10/35
– – 9/45
7/9 10/12 –
–
5/35
– 10/45 9/45
3/35 – –
37/45 8/45 –
– – 35/35
Adipocytokine levels (median, range) in different cytogenetically classified acute leukemia patients
Acute leukemia Leptin (ng/ml) Adiponectin (ng/ml)
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unfavorable group and the differences were statistically significant (P ≤ 0.00 for both) (Table 2). Serum leptin levels were significantly higher in acute lymphoblastic leukemia patients compared to controls (P = 0.01). On the other hand, serum leptin levels were significantly lower in acute myeloid leukemia (AML) as compared with controls (P = 0.00) (Table 3, Fig. 1). Furthermore, serum adiponectin levels were significantly lower in ALL and AML patients compared to controls (P = 0.01, 0.00, respectively) (Table 3, Fig. 2). Correlation studies regarding serum leptin levels; while there were positive significant correlation with BM blast cells percentage (r = 0.79, P < 0.001), blood total WBCs counts (r = 0.54, P < 0.01), sLDH (r 0.738, P < 0.001) in ALL group; there were significant negative correlations with BM blast cells (r 0.542, P < 0.01) and sLDH (r = −0.699, P
0.05) in the AML group (Tables 4 and 5). Moreover, there were significant negative correlation between serum adiponectin levels and bone marrow blast cells and serum lactic dehydrogenase (LDH) in whole acute leukemia group (r −0.542, P < 0.01, r −0.699, P < 0.001, respectively) (Table 6).
Table 5 Correlation between serum leptin levels and BM blast cells, blood leucocytic counts, and sLDH in ALL patients
Table 4 Correlation between serum adiponectin levels and BM blast cells, WBCs, sLDH in acute leukemia patients
Table 6 Correlation between serum leptin levels and BM blast cells, WBCs, LDH in AML patients
Adiponectin (ng/mL)
Blast cells (BM)
WBCs × 103/cmm (blood)
r P value
−0.599 0.05
Leptin (ng/mL)
Blast cells% (BM)
WBCs × 103/cmm (blood)
LDH (IU/l)
r P value
0.74 0.01
0.59 0.02
0.738 0.01
LDH (IU/L)
Leptin (ng/mL)
Blast cells (BM)
WBCs × 103/cmm (blood)
LDH (IU/l)
−0.762
