Characterization of Epstein-Barr viral strains in parotid gland saliva and peripheral blood of patients with primary Sjogren's syndrome and healthy EBV carriers

Increased Epstein-Barr virus (EBV) replication has been reported in the salivary and lacrimal glands in Sjögren's syndrome (SS). We studied whether or not certain EBV strains would occur preferentially in the peripheral blood and parotid gland saliva of 18 EBV-seropositive patients with primary Sjögren's syndrome (pSS) and 12 EBV-seropositive control persons. Transforming EBV was detected in the blood of 11 of 18 (61%) pSS patients and 9 of 12 controls (75%). Unexpectedly, neither transforming nor Raji-superinfecting EBV strains were detected in SS parotid saliva, whereas these EBV types were detected in control saliva in 7 and 8 cases, respectively (P <0.001). Transforming EBV strains were further characterized by ‘Ebnotyping,’ i.e., analysis of the size spectrum of the viral antigens EBNA 1, 2, 3, and 6 in immunoblots of lymphoblastoid cell lines (LCL). Previous work has shown that a single EBV strain (Ebnotype) dominates the blood and oropharynx of healthy carriers and that unrelated individuals carry different EBV strains, reflecting the vast polymorphism of Ebnotypes in the general population. Two unexpected observations were made. First, an identical Ebnotype was detected in 4 unrelated individuals, i.e., in the blood of 1 pSS patient and in the saliva of 3 control persons. Second, carriage of 2 to 4 different Ebnotypes by a single individual was observed in 4 cases, i.e., in the blood of 1 pSS patient, and in the blood and saliva of 3 control persons. As only 1 control person had received a blood transfusion, it is suggested that (super)infection with exogenous EBV strains via salivary transmission and/or recombination of endogenous virions may have contributed to this situation

Detection of EBV-DNA in serum samples of an immunosuppressed child during a three years follow-up: association of clinical and PCR data with active infection Detecção de EBV-DNA em amostras de soro de criança imunodeprimida durante três anos de seguimento: associação de dados clínicos e de PCR com a infecção ativa

Twenty-four whole blood and serum samples were drawn from an eight year-old heart transplant child during a 36 months follow-up. EBV serology was positive for VCA-IgM and IgG, and negative for EBNA-IgG at the age of five years old when the child presented with signs and symptoms suggestive of acute infectious mononucleosis. After 14 months, serological parameters were: positive VCA-IgG, EBNA-IgG and negative VCA-IgM. This serological pattern has been maintained since then even during episodes suggestive of EBV reactivation. PCR amplified a specific DNA fragment from the EBV gp220 (detection limit of 100 viral copies). All twenty-four whole blood samples yielded positive results by PCR, while 12 out of 24 serum samples were positive. We aimed at analyzing whether detection of EBV-DNA in serum samples by PCR was associated with overt disease as stated by the need of antiviral treatment and hospitalization. Statistical analysis showed agreement between the two parameters evidenced by the Kappa test (value 0.750; p < 0.001). We concluded that detection of EBV-DNA in serum samples of immunosuppressed patients might be used as a laboratory marker of active EBV disease when a Real-Time PCR or another quantitative method is not available.<br>Vinte e quatro amostras de sangue total e de soro foram colhidas durante seguimento por 36 meses de criança de oito anos de idade, imunodeprimida devido a transplante cardíaco. O paciente apresentou VCA-IgG e IgM positivos e EBNA-IgG negativo aos cinco anos de idade quando foi diagnosticada mononucleose infecciosa. Quatorze meses depois o VCA-IgG e o EBNA-IgG eram positivos e o VCA-IgM negativo. Este padrão sorológico persiste desde aquela época mesmo durante episódios sugestivos de reativação. As amostras de sangue total e de soro foram analisadas pela Reação em Cadeia da Polimerase (PCR) que amplificou fragmento oriundo da gp220 do EBV (detecção de 100 cópias virais). Todas as 24 amostras de sangue total e 12 amostras de soro foram positivas por PCR. Com o objetivo de verificar se a detecção de DNA do EBV em soro estaria associada à reativação da doença, os resultados de PCR foram analisados em relação à necessidade de hospitalização e uso de anti-viral. O teste de Kappa mostrou que existe concordância entre a presença de DNA do EBV em soro e a necessidade de hospitalização e tratamento com anti-virais (valor de 0,750; p < 0,001). Concluímos que a detecção de DNA do EBV em amostras de soro de pacientes imunosuprimidos poderia ser usada como marcador laboratorial de atividade da infecção quando técnicas quantitativas de amplificação não estiverem disponíveis