EXPRESSION OF EBV ENCODED LATENT MEMBRANE-PROTEIN-1 (LMP-1) AND BCL-2PROTEIN IN CHILDHOOD AND ADULT HODGKINS-DISEASE - APPLICATION OF MICROWAVE IRRADIATION FOR ANTIGEN RETRIEVAL

Surgical biopsies obtained from 32 children, and 34 adults with Hodgki n's disease (HD) were investigated for the expression of the EBV encod ed Latent Membrane Protein 1 (LMP-1), bcl-2 protein, markers for HD; L euM1 (CD15), BerH2 (CD30) and the new BLA.36, as well as for B (L26) a nd T lymphocytes (UCHL1). Before immunostaining, sections were subject ed to an Antigen Retrieval (AR) procedure based on microwave irradiati on in citrate buffer. In 13 cases staining with and without the AR pro cedure was compared. Immunoreactivity for LMP-1 was found in 44% of th e 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. Immunoreactivit y with BLA.36 was found in 94% of the biopsies from adults and 100% fr om children, with LeuM1 in 83% from adults and 93% from children and w ith BerH2 in 24% from adults and 84% from children. Nuclear PCNA stain ing 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 a dult and 9% cases from the childhood cases we observed reactivity with the B cell marker (L26) in HRS cells. We can conclude that antigen re trieval improves immunostaining results of paraffin sections which wer e previously negative for bcl-2, LeuM1 and BerH2 antibodies. The high percentage of LMP-1 positive cases, both in adults and in children, in dicates that the potential pathogenetic effect of EBV may be of simila r importance both in childhood and in adult HD. The new MAb BLA.36 gav e consistent immunostaining with HRS cells but also with other cell ty pes. In a panel of markers for HRS cells BLA.36 together with LeuM1 (C D15) and BerH2 (CD30) are useful.