Expression of EBV Encoded Latent Membrane Protein 1 (LMP-1) and bcl-2 Protein in Childhood and Adult Hodgkin's Disease: Application of Microwave Irradiation for Antigen Retrieval

Abstract
Surgical biopsies obtained from 32 children, and 34 adults with Hodgkin's disease (HD) were investigated for the expression of the EBV encoded Latent Membrane Protein 1 (LMP-1), bcl-2 protein, markers for HD; LeuM1 (CD 15), BerH2 (CD30) and the new BLA.36, as well as for B (L26) and T lymphocytes (UCHL1). Before immunostaining, sections were subjected to an Antigen Retrieval (AR) procedure based on microwave irradiation in citrate buffer. In 13 cases staining with and without the AR procedure was compared. Immunoreactivity for LMP-1 was found in 44% of the biopsies from adults and 53% from children. We also found reactivity for the bcl-2 protein in Hodgkin's and Reed Sternberg (HRS) cells in 48% of the biopsies from adults and 45% from children. Immunoreactivity with BLA.36 was found in 94% of the biopsies from adults and 100% from children, with LeuM1 in 83% from adults and 93% from children and with BerH2 in 24% from adults and 84% from children. Nuclear PCNA staining was seen in HRS in all cases both adult and childhood. The T cell marker (UCHL1) displayed no reactivity with HRS cells. In 21% of the adult and 9% cases from the childhood cases we observed reactivity with the B cell marker (L26) in HRS cells.