INACTIVATED COVID-19 VACCINE CAN INDUCE REACTIVE POLYARTHRITIS IN OLDER PATIENTS: REPORT OF TWO CASES.

Reactive arthritis is an acute, sterile, non-suppurative and inflammatory arthropathy that usually follows infection process. Gastrointestinal, genitourinary and respiratory tract infections generally provoke reactive arthritis. Also, reactive arthritis can be seen after vaccination. Reactive arthritis cases have been reported after tetanus, combined diphteria-poliomyelitis-tetanus toxoid, hepatitis B or influenza vaccination. Although reactive arthritis is more common in youngs, healthcare workers should be aware of the development of post inactivated COVID-19 vaccine reactive arthritis in older patients. We present two cases with ReA induced by inactivated coronavirus 2019 (COVID-19) vaccination (CoronaVac, Sinovac). Both patients in our study were over 70 years old and presented with polyarthritis that developed after vaccination. Rheumatoid factor and anti-nucleer antibody were negative and patients responded well to short-term steroid therapy, arthritis were not resistant.

Epstein-Barr virus gH is essential for penetration of B cells but also plays a role in attachment of virus to epithelial cells.

Entry of Epstein-Barr virus (EBV) into B cells is initiated by attachment of glycoprotein gp350 to the complement receptor type 2 (CR2). A complex of three glycoproteins, gH, gL, and gp42, is subsequently required for penetration. Gp42 binds to HLA class II, which functions as an entry mediator or coreceptor and, by analogy with other herpesviruses, gH is then thought to be involved virus-cell fusion. However, entry of virus into epithelial cells is thought to be different. It can be initiated by attachment by an unknown glycoprotein in the absence of CR2. There is no interaction between gp42 and HLA class II and instead a distinct complex of only the two glycoproteins gH and gL interacts with a novel entry mediator. Again, by analogy with other viruses gH is thought to be critical to fusion. To investigate further the different roles of gH in infection of the two cell types and to examine its influence on the assembly of the gH-gL-gp42 complex, we constructed two viruses, one in which the gH open reading frame was interrupted by a cassette expressing a neomycin resistance gene and the gene for green fluorescent protein and one as a control in which the neighboring nonessential thymidine kinase gene was interrupted with the same cassette. Virus lacking gH exited from cells normally, although loss of gH resulted in rapid turnover of gL and gp42 as well. The virus bound normally to B lymphocytes but could not infect them unless cells and bound virus were treated with polyethylene glycol to induce fusion. In contrast, virus that lacked the gH complex was impaired in attachment to epithelial cells and the effects of monoclonal antibodies to gH implied that this resulted from loss of gH rather than other members of the complex. These results suggest a role for gH in both attachment and penetration into epithelial cells.

Epstein-Barr virus uses HLA class II as a cofactor for infection of B lymphocytes.

Infection of B lymphocytes by Epstein-Barr virus (EBV) requires attachment of virus via binding of viral glycoprotein gp350 to CD21 on the cell surface. Penetration of the cell membrane additionally involves a complex of three glycoproteins, gH, gL, and gp42. Glycoprotein gp42 binds to HLA-DR. Interference with this interaction with a soluble form of gp42, with a monoclonal antibody (MAb) to gp42, or with a MAb to HLA-DR inhibited virus infection. It was not possible to superinfect cells that failed to express HLA-DR unless expression was restored by transfection or creation of hybrid cell lines with complementing deficiencies in expression of HLA class II. HLA class II molecules thus serve as cofactors for infection of human B cells.

The Epstein-Barr virus (EBV) BZLF2 gene product associates with the gH and gL homologs of EBV and carries an epitope critical to infection of B cells but not of epithelial cells.

Glycoprotein gp85, the product of the BXLF2 open reading frame (ORF), is the gH homolog of Epstein-Barr virus (EBV) and has been implicated in penetration of virus into B cells. Like its counterparts in other herpesviruses, it associates with a gL homolog, gp25, which is the product of the BKRF2 ORF. Unlike the gH homologs of other herpesviruses, however, gp85 also complexes with two additional glycoproteins of 42 and 38 kDa. Glycoproteins gp42 and gp38 were determined to be alternatively processed forms of the BZLF2 gene product. Coexpression of EBV gH and gL facilitated transport of gH to the cell surface and resulted in formation of a stable complex of gH and gL. It also restored expression of an epitope recognized by monoclonal antibody E1D1, which immunoprecipitates the native gH complex but not recombinant gH expressed in isolation. Coexpression of gH, gL, and the BZLF2 ORF restored expression of an epitope recognized by a second monoclonal antibody, F-2-1, which immunoprecipitates the native gH-gL-gp42/38 complex but not the complex of recombinant gH and gL alone. The epitope recognized by antibody F-2-1 was mapped to the BZLF2 gene product itself. Antibody F-2-1 inhibited the ability of EBV to infect B lymphocytes but had no effect on the ability of the virus to infect the epithelial cell line SVK-CR2. In contrast, antibody E1D1 had no effect on infection of the B-cell line but inhibited infection of the epithelial cell line. These results indicate that penetration of the two cell types by EBV involves differential use of the gH-gL-gp42/38 complex and suggest the hypothesis that the BZLF2 gene product has evolved as a unique adaptation to infection of B lymphocytes by EBV.

The Epstein-Barr virus-associated protein p105 is not encoded by the Epstein-Barr virus genome.

Rabbit antibodies made to an Epstein-Barr virus (EBV)-associated hydrophobic protein p105 that cross-reacts antigenically with the herpes simplex virus glycoprotein gB inhibited the ability of EBV to induce immunoglobulin synthesis by normal B cells. Sequencing of p105 indicated that it was a keratin-like protein and not encoded by EBV. Analysis of EBV-producing cells with and without mycoplasma indicated that p105 is probably a mycoplasma protein that associates with the EBV virion.

A case of Pyemotes dermatitis. With a note on the role of these mites in skin disease.

Acute dermatitis developed in a fisherman after contact with old cherry-wood. A Pyemotes mite, probably P. beckeri, found in the wood, was thought to be responsible--thus illustrating the importance of appropriate laboratory examinations for ectoparasites. Human skin erruptions caused by indigenous, in contrast to imported, Pyemotes species have not previously been reported in Britain. These tarsonemoid mites attack small insect hosts and their possible role in dermatoses is discussed. Dermatitis caused by these mites is probably world-wide in distribution, but during the last century the confusing acarological nomenclature surrounding Pyemotes has resulted in an equally confusing variety of dermatological diagnoses.