Increased soluble HLA-DRB1in B-cell acute lymphoblastic leukaemia.
Soluble HLA (sHLA) are potential tumour markers released in order to counter immune surveillance. sHLA-class II is less known especially in acute lymphoblastic leukaemia (ALL). This study aimed to investigate soluble, surface and allelic expression of HLA Class II (sHLA-DR) in B-cell ALL patients and compare with soluble expression in normal individuals. A sandwich enzyme-linked immunosorbent assay (ELISA) was developed to measure soluble HLA-DRB1 in plasma. Flow cytometric analysis was performed to determine median fluorescence intensity in HLA-DR surface expression. HLA-DNA typing by polymerase chain reaction, sequence specific oligonucleotides, PCRSSO was performed to determine HLA-DRB1 type in ALL samples. Results showed sHLA-DRB1 (mean±SEM) was significantly increased (p=0.001) in plasma of ALL patients (0.260 ±0.057 μg/mL; n=30) compared to healthy controls (0.051 ± 0.007µg/mL; n=31) of Malay ethnicity. However, these levels did not correlate with percentage or median fluorescence intensity of HLA-DR expressed on leukemia blasts (CD19+CD34 ± CD45(lo)HLA-DR+) or in the normal B cell population (CD19+CD34- CD45(hi)HLA-DR+) of patients. No significant difference was observed in gender (male/female) or age (paediatric/adult). Only a trend in reduced sHLA was observed in patients carrying HLA-DR04. These results have to be validated with a larger number of samples.
Universiti Putra Malaysia, Department of Pathology, Immunology Unit, 43400 UPM Serdang, Selangor, Malaysia. maha@upm.edu.my.
Norfazieda
N
Hassan
Jasbir Singht
JS
Dhaliwal
Hishamshah
H
Mohd Ibrahim
Raudhawati
R
Osman
Siti-Zuleha
SZ
HIdris
Le Jie
le J
Lee
Maha
M
Abdullah
D000293:Adolescent; D000328:Adult; D014408:Biomarkers, Tumor / Q000032:analysis*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D059811:HLA-DRB1 Chains / Q000096:biosynthesis*; D006801:Humans; D008297:Male; D016133:Polymerase Chain Reaction; D015452:Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / Q000276:immunology* / Q000473:pathology; D055815:Young Adult
D014408:Biomarkers, Tumor; D059811:HLA-DRB1 Chains