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+/-CD45loHLA-DR+) or in the normal B cell population (CD19+CD34- CD45hiHLA-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.

The Wiskott-Aldrich Syndrome (WAS) is an X-linked immunodeficiency condition characterized by microthrombocytopenia, eczema and recurrent infections. It is caused by mutations in the Wiskott-Aldrich Syndrome protein (WASP) gene. We investigated two Malay boys who presented with congenital thrombocytopenia, eczema and recurrent infections. Here we report two cases of WASP mutation in Malaysia from two unrelated families. One had a novel missense mutation in exon 1 while the other had a nonsense mutation in exon 2. Both patients succumbed to diseaserelated complications. A differential diagnosis of WAS should be considered in any male child who present with early onset thrombocytopenia, especially when this is associated with eczema and recurrent infections.

An RT-PCR assay detected the t(4;11) translocation in two infants with acute lymphoblastic leukemia (ALL). Case P76 was a 10-month-old, female infant, who presented with a WBC of 137.4 x 10(9)/l and a pre-pre-B ALL immunophenotype. Case P120 was a 6-month-old female infant, with a WBC > 615 x 10(9)/l and a pre-pre-B ALL immunophenotype. RT-PCR of cDNA from both these cases generated a 656 bp and a 542 bp respectively, which sequencing confirmed as t(4;11) fusion transcripts. The primers and conditions selected for this assay are compatible with a one-step multiplex PCR for the main translocations in childhood ALL.
Lower case tea ; Leukemia, Lymphocytic, Acute ; Reverse Transcriptase Polymerase Chain Reaction ; L ; Lower case ecks