Epstein-Barr virus (HHV-4) inoculation to rabbits by intranasal and oral routes results in subacute and/or persistent infection dissimilar to human disease.

OBJECTIVE: We report the infection of New Zealand white rabbits with Epstein-Barr virus (EBV). METHODS: EBV prepared in B95-8 (producer) cells was inoculated to rabbits by combined intranasal and oral routes. Blood and white blood cell (WBC) samples were taken before infection, then on days 8, 28 and 98 post-infection (p.i.). RESULTS: Administration of either 3 × 10(8) (group A, 11 rabbits) or 1 × 10(9) (group B, 10 rabbits) EBV DNA copies per animal induced subacute and/or persistent infection. The IgG antibodies in plasma were detected by ELISA as well as by immunoblot (IB). The IB bands showed mainly antibodies to the BZRF1/Zta transactivation polypeptide (69.2%), the p54 early protein (53.4%) and to the p23 capsid protein (35.8%). No anti-EBNA1 antibody was detected throughout. Viral DNA could be detected by PCR in WBCs and/or spleen of 7 out of 21 infected rabbits (30%), while 60-80% of them showed serologic response. The transiently present EBV DNA was accompanied by LMP1 antigen. CONCLUSIONS: Rabbits developed persistent EBV infection in the absence of EBNA1 antibodies and by the lack of typical infectious mononucleosis-like syndrome. The absence of EBNA1 antibody may reflect the lack of EBNA1 in B cells of EBV-inoculated rabbits.

Effect of low-pathogenicity influenza virus H3N8 infection on Mycoplasma gallisepticum infection of chickens.

Mycoplasma infection is still very common in chicken and turkey flocks. Several low-pathogenicity avian influenza (LPAI) viruses are circulating in wild birds that can be easily transmitted to poultry flocks. However, the effect of LPAI on mycoplasma infection is not well understood. The aim of the present study was to investigate the infection of LPAI virus H3N8 (A/mallard/Hungary/19616/07) in chickens challenged with Mycoplasma gallisepticum. Two groups of chickens were aerosol challenged with M. gallisepticum. Later one of these groups and one mycoplasma-free group were aerosol challenged with the LPAI H3N8 virus. The birds were observed for clinical signs for 8 days, then euthanized, and examined for the presence of M. gallisepticum in the trachea, lung, air sac, liver, spleen, kidney and heart, and for developing anti-mycoplasma and anti-viral antibodies. The LPAI H3N8 virus did not cause any clinical signs but M. gallisepticum infection caused clinical signs, reduction of body weight gain and colonization of the inner organs. These parameters were more severe in the birds co-infected with M. gallisepticum and LPAI H3N8 virus than in the group challenged with M. gallisepticum alone. In addition, in the birds infected with both M. gallisepticum and LPAI H3N8 virus, the anti-mycoplasma antibody response was reduced significantly when compared with the group challenged with M. gallisepticum alone. Co-infection with LPAI H3N8 virus thus enhanced pathogenesis of M. gallisepticum infection significantly.

[Is the primary antiphospholipid syndrome a forerunner of SLE?]. / Primer antifoszfolipid szindróma: a szisztémás lupus erythematosus elofutára?

INTRODUCTION: Antiphospholipid syndrome is a multi-organ autoimmune disorder, characterized by arterial and venous thrombotic events, and a well-defined group of recurrent foetal wasteage due to pathologic antibodies against phospholipids and protein co-factors. Antiphospholipid antibodies can be formed in primary antiphospholipid syndrome, but also in other conditions, most often in systemic lupus erythematosus. This may modify the outcome of lupus increasing the risk for thrombotic complications. Less is known about the outcome in primary antiphospholipid syndrome, whether it may precede the development of systemic lupus. AIMS: Authors hereby describe the case of four patients with primary antiphospholipid syndrome in whom the disease progressed to systemic lupus erythematosus. RESULTS: Lupus followed the primary antiphospholipid syndrome within around a three-year period. It was indicated by the appearance of different antinuclear autoantibodies and clinical complications, such as polyarthritis, nephritis and hematologic disturbances. All of the patients presented cerebrovascular accident as the thrombotic manifestation. All but one, were around forty years old, and had a milder form of lupus. Symptoms of the antiphospholipid syndrome determined the outcome. On the other hand, a typical lupus developed in the youngest patient. CONCLUSIONS: According to present cases antiphospholipid syndrome may be considered as the initiative phase of SLE, but APS being a separate entity also may associate to lupus. Present observations indicate the importance of follow-up the patients with APS by immunologic respect. Future prospective, multi-centre studies with larger number of cases are needed to provide further evidence on the fact that patients with APS may acquire other autoimmune disorder.

Immunoglobulin G from patients with antiphospholipid syndrome impairs the fibrin dissolution with plasmin.

Immunoglobulin G (IgG) isolated from normal human blood plasma stabilizes the structure of perfused crosslinked fibrin and prolongs the time for its dissolution with plasmin, when the fibrin surface is exposed to 500 s(-1) shear rate flow. The IgG from patients suffering in antiphospholipid syndrome with thrombotic complications exerts even stronger antifibrinolytic effect. A patient, whose IgG does not affect the fibrin dissolution with plasmin, displays a bleeding tendency. The shear stress-induced disassembly of the fibrin clots containing IgGs with antifibrinolytic potency occurs at a much more advanced stage of fibrin digestion, as evidenced by the electrophoretic pattern of the ureatreated samples. The antifibrinolytic effects are also produced under static conditions and these are caused by the variable portion of the IgG molecules (fragment Fab), whereas the constant part (fragment Fc) has no inhibitory effect. The IgGs with antifibrinolytic properties do not affect directly the plasmin activity in amidolytic assay, but the IgGs from APS patients obliterate the competition of the fibrin and the peptidyl-p-nitroanilide for the protease in the same assay system suggesting interference of the IgGs with the plasmin action on the fibrin substrate. Thus, the correlation of the clinical symptoms with the effect of the isolated IgG on the dissolution of perfused fibrin clots supports a physiological and a pathological role of IgG in the fibrinolytic process related to the variability of the cross-reactions of immunoglobulins with fibrin, fibrin degradation products or fibrin-plasmin complexes.

Complement Synthesis Influencing Factors Produced by Acute Myeloid Leukemia Blast Cells.

In a previous study, we found hypercomplementaemia in the sera of acute myeloid leukemia patients. In this study we show that the supernatants of mononuclear cells, derived from peripheral blood taken in the blastic phase, from patients with acute myeloid leukemia (CM-AML) increased the in vitro complement protein synthesis of HepG2 hepatocellular carcinoma cells. This effect of CM-AML was mediated by heat labile soluble factors and involved the synthesis of mRNA and protein. Inhibition experiments with anti-cytokine antibodies and immunoaffinity chromatography revealed that this effect of CM-AML is mostly mediated by IL-1 and IL-6.