Serological evidence for reactivation of EBV infection due to uraemic immunodeficiency.

BACKGROUND: Reactivation of EBV infection is a common finding in immunocompromised individuals. The influence of 'uraemic immunodeficiency' on EBV infection is so far not well defined. METHODS: We determined specific antibodies to EBV nuclear antigens (EBNA) 1 and 2 in sera of 286 patients with immunodeficiency due to progressive chronic renal failure and of 51 healthy controls. We used the baculovirus vector expression system for recombinant production of EBNA1 and EBNA2. RESULTS: Serological evidence of reactivated or chronic persistent EBV infection, i.e. an anti-EBNA1/anti-EBNA2 ratio (E1/E2) < 1, was found in 18% of patients with chronic renal failure not yet receiving renal replacement therapy (CRF), 11% of peritoneal dialysis patients (CAPD), 25% of haemodialysis patients (HD), 24% of renal transplant recipients (TX), and in 6% of healthy controls. Rate of EBV reactivation was significantly increased in HD (P = 0.004) and TX (P = 0.006) patients compared to healthy controls. Moreover, the difference between HD and CAPD patients was statistically significant (P < 0.05). This finding may reflect additional effects modulating the function of the immunosystem, probably through activation of immunologically competent cells by contact with the artificial surfaces of dialysis membranes. Although the rate of EBV reactivations is expected to increase further under conditions of therapeutic immunosuppression, our serological approach did not detect an additional effect of immunosuppressive therapy following renal transplantation. However, this finding may reflect an impaired endogenous synthesis of antibodies caused by immunosuppressive agents. CONCLUSIONS: We conclude that determination of E1/E2 is useful for assessment of EBV infection in patients with chronic renal failure and 'uraemic immunodeficiency'. In patients with immunosuppressive therapy following renal transplantation additional testing including direct estimation of viral load, is necessary to correctly assess the state of EBV infection.

[Malnutrition in hemodialysis patients. Self-assessment, medical evaluation and "verifiable" parameters]. / Malnutrition bei Hämodialysepatienten. Selbsteinschätzung, ärztliche Beurteilung und "objektivierbare" Parameter.

BACKGROUND: Malnutrition in hemodialysis patient is associated with increased mortality and morbidity. Inventions to treat malnutrition are often ineffective. Underestimation by the patients of the importance of dietary interventions might negatively influence any therapeutic outcome. We examined the correlation between nutritional assessment by the patient himself and clinical assessment by the physician. PATIENTS AND METHODS: Subjective global assessment (SGA) was performed in 68 chronic hemodialysis patients Serum concentrations of albumin, prealbumin, transferrin and cholesterin were measured Protein intake was estimated by protein catabolic rate (nPCR). In form of a questionnaire patients were asked to assess then own nutrition. RESULTS: According to SGA-criteria, moderate to severe malnutrition was found in 34% of our patients. In this unauthorized group serum albumin was < 4.0 g/dl in 45% of patients and correlated best with clinical nutritional assessment. Specificity was lower for prealbumin, transferrin, cholesterin, and nPCR. The questionnaire was completed by 85% of patients. Self-assessment of their own nutrition was discrepant to clinical assessment in 84% of malnourished patients. A similar percentage (79%) of malnourished patients considered their own body weight to be adequate, while only 21% indicated desire to gain weight. CONCLUSIONS: Our data indicate that a significant percentage of malnourished hemodialysis patients shows a tendency to overestimate their own nutrition. This may negatively influence patient compliance and should be considered in dietary counseling of malnourished chronic hemodialysis patients.

Sero-epidemiological analysis of the risk of virus infections for childhood leukaemia.

Virus infections have been thought to be involved in the development of childhood leukaemia. In order to address this issue we determined, in a case-control study, the prevalence of antibodies to viruses infecting blood or bone-marrow cells [Epstein-Barr virsus (EBV), human herpes virus type 6 (HHV-6), parvovirus B19] as well as to the human virus known for its tumour-suppressive properties, the adeno-associated virus type 2 (AAV-2), in the sera of 121 children with leukaemia in Germany, and in 197 control individuals, hospitalized for other reasons, and matched for age and gender to the cases. In addition, we developed a questionnaire to be answered by the children's parents, in order to gain information on previous infections of the children as well as to calculate for factors which may influence serological findings. Comparative determination of the prevalence of antibodies against AAV-2, B-19 or HHV-6 revealed no significant differences in cases and controls. However, antibodies to EBV were more frequently found in children with leukaemia younger than 6 years of age (age at the time of diagnosis of leukaemia) than in controls. Apparently, infection with AAV-2 has no protective effect in childhood leukaemia, in contrast to results observed for other malignancies. Similarly, and in accordance with results on leukaemia in adults, we found no indication of a protective effect of infection with the parvovirus B-19. The data suggest that EBV, which is known to be involved in various lymphomas, may play a role in the development of childhood leukaemia in young children.

Anti-EBNA1/anti-EBNA2 ratio decreases significantly in patients with progression of HIV infection.

Reactivation of EBV infection is common in immunocompromised individuals. We determined specific antibodies to EBV-encoded nuclear antigens (EBNA)1 and 2 in 102 sera of HIV-infected individuals. Anti-EBNA1/anti-EBNA2 ratio (E1/E2) is less than 1 in chronic infection and exceeds 1 in healthy EBV-positive carriers. 52% of cases had E1/E2 < 1. E1/E2 decreased remarkably during the progression of HIV infection. Detectable HIV-Antigen, decline of CD4+ cell count and CD4+/CD8+ ratio were correlated with an increasing prevalence of E1/E2 below 1. We conclude that determination of E1/E2 is useful in immunocompromised patients.