Cd44 expression and soluble cd44 as a potential marker of tumor load in pediatric acute leukemia

Abstract EN

Background : CD44 standard transcript (CD44s) is known to be widely expressed on ANLL and in a high percentage of ALL where it is reported to correlate with tumor burden.

Different isoforms have been reported to be expressed on ANLL and/or ALL with various impacts on prognosis.

In the present study the expression of CD44s and its variant isoforms CD44v4, v6 and v7 / 8 were analyzed in 76 newly diagnosed children with acute leukemia and correlated with immunophenotyping, TLC and tumor burden.

Patients and Methods : the cases comprised 62 ALL and 14 ANLL cases, ALL cases included 42 males and 20 females with an age range of 1 to 17 years, a mean of 3.6 years and a median of 4 years.

ANLL cases included 4 males and 10 females with an age range of 2 to 16 years, a mean of 9 years and a median of 9.5 years.

Results : CD44s was detected on all ANLL and 98.3 % (61 / 62) of ALL cases tested.

CD44v4 was encountered, probably for the first time, in 7 / 52 ALL and 1 / 14 ANLL ; no other variants were encountered.

Serum CD44 (sCD44) level was elevated in 25 / 35 ALL and in 11 / 14 ANLL with no correlation to CD44s expression.

Conclusion : CD44 variant isoform expression could be used as a marker for monitoring minimal residual disease (MRD) in positive cases.

Serum CD44s levels can also be used as a tumor marker for follow up of patients and monitoring of therapy in ALL and ANLL cases independent of CD44 expression.