EPSTEIN-BARR VIRUS STATUS AND THE HISTOPATHOLOGICAL CHANGES OF PAROTID GLAND LYMPHOID INFILTRATES IN HIV-POSITIVE CHILDREN RUNJAN CHETTY *, MANICKAVALLIE VAITHILINGUM † AND RAJENDRA THEJPAL † Departments of Pathology* and Paediatrics†, University of Natal School of Medicine and King Edward VIII Hospital, Durban, South Africa Summary This study examined the EBV status and the morphology in parotid glands of a large cohort of HIV-positive pediatric patients. Nineteen children with vertically acquired HIV infection, ranging in age from three months to seven years and two months, were analyzed. Seventeen patients were assessed for serological evidence of EBV infection; nine showed evidence of past infection, one each re-activation and current infection and six did not have serological evidence of EBV. Immunohistochemistry and in situ hybridization for EBER 1 and 2 were performed on formalin-fixed, paraffin-embedded tissue. Fourteen of the 19 cases were classified as severe or established myoepithelial sialadenitis (MESA) and five were regarded as having mild MESA. The majority of intraepithelial lymphocytes were of B-cell lineage, while the pericystic infiltrate contained CD8-positive T-lymphocytes. p24 immu- nohistochemistry for HIV showed positive follicular dendritic cells, lymphoid cells and macrophages. Ten of 14 cases were positive for EBER 1 and 2. These included cases that were serologically negative for EBV. This study confirms that the morphology and immunophe- notype of pediatric HIV-associated parotid lesions are similar to those seen in adults. Ten of 14 cases with evidence of EBV within the lymphoid infiltrate showed the same morphology and immunophenotype as cases in which EBV was not detected either by serology or by in situ hybridization. These findings indicate that EBV is not uniformly found in either the tissue or serum of these patients, and may not have a pathogenetic role in HIV-associated lymphoepithelial lesions in the pediatric age group. Key words: Epstein-Barr virus, Human immunodeficiency virus, immuno- histochemistry lymphoepithelial lesions, myoepithelial sialadenitis. Abbreviation: MESA, myoepithelial sialadenitis. Accepted 1 July 1999 INTRODUCTION It is well known that the human immunodeficiency virus (HIV)-1 induces perturbation of the immune system by killing CD4 T-helper lymphocytes and by causing depletion of memory T-helper cells, among other mechanisms of achieving immune dysregulation. 1,2 In some patients expressing certain major histocompatibility complex (MHC) alleles, HIV infection causes an antigen-driven oligoclonal expansion of CD8 + lymphocytes. 1,3 These cells home in on the salivary glands (producing a Sj¨ ogren’s syndrome-like picture), the lungs (causing bronchopulmo- nary lymphoid hyperplasia or lymphoid interstitial pneumo- nia complex) and other viscera. This process has been labelled “diffuse infiltrative lymphocytosis syndrome”. 4 The clinical and epidemiological considerations of this syndrome were thoroughly investigated by Kazi et al. 2 As part of the pathological picture, lymphoepithelial cysts in the salivary glands were noted in HIV-positive patients, and this association has been regarded as being characteristic. With reference to HIV-infected children, McClain et al. and Joshi and colleagues described the spectrum of lymphopro- liferative lesions seen in mucosa-associated lymphoid tissue (MALT). 5,6 The latter paper was based on six patients ranging in age from 28 months to 23 years. The purpose of this paper is to address the Epstein–Barr virus (EBV) and morphological findings in the parotid glands in a larger cohort of HIV-infected children from a different geo- graphical area. All patients in this study had vertically acquired HIV infection and did not receive any anti-viral therapy. MATERIALS AND METHODS Patients and clinical information Nineteen patients with vertically acquired HIV infection and parotid enlargement were studied. Informed consent was obtained from all mothers for serological testing and biopsy. None received anti-viral treatment prior to biopsy. Trucut needle biopsies were performed to investigate the cause of the parotid swelling. ELISA and Western blotting techniques confirmed the HIV status of the patients. EBV serology for viral capsid antigen (VCA) IgM and nuclear antigen (NA) IgG was tested using ELISA and IFA on 17 of the 19 patients. Light microscopy All biopsies were fixed in 10% buffered formalin, processed routinely and H & E sections were cut. Histological assessment of the cases was based on the criteria suggested by Diss et al. and subsequently modified by Quintana et al. 7,8 Immunohistochemistry Immunohistochemistry was performed on the formalin-fixed, paraffin- embedded tissue after microwave antigen retrieval using the streptavidin– biotin complex technique with diaminobenzidine (DAB) as chromogen. The following antibodies were used against: CD3 (Dakopatts, Copenhagen, ISSN 0031–3025 printed/ISSN 1465–3931 online/99/040413–5 © 1999 Royal College of Pathologists of Australasia Pathology (1999) 31, pp. 413–417