The drug hypersensitivity syndrome, DRESS is not due to an allergy but the reactivation of virus in a latent state in patients. These data could improve the treatment offered to victims of the syndrome.
DRESS syndrome (Drug Rash with Eosinophilla and systemic symptoms) has been described for the first time in the late 1950s but his name has been given in 1997 by French researchers from the Department of Dermatology, Henri Mondor Hospital in Paris . This drug hypersensitivity observed in the weeks after taking a drug type current antibiotic or anti-epileptic. This syndrome affects approximately one in 8000 and led to the death of 10% of them. The symptoms are similar to those of infection (fever, swollen lymph nodes) and can become serious when the inflammation spreads to the liver, kidney, lung or heart.
The doctors assumed that it was an allergic reaction against the drug in question since the symptoms were related to excessive production of blood cells eosinophils, cells of the immune system may be involved in the phenomena of hypersensitivity. This is again a team of French researchers, this time based in Rouen Inserm (Unit 905, Pathophysiology and biotherapy of inflammatory and autoimmune diseases) and conducted by Philippe Musette, who had advance knowledge of the syndrome DRESS proposing a new theory, presented in the journal Science, Translational Medicine.
To do this, the researchers analyzed the cases of 40 patients with this syndrome after taking one of three drugs, including carbamazepine, sulfamethoxazole and allopurinol. In 76% of them, the multiplication of a virus in the blood, the Epstein-Barr virus (EBV), responsible for mononulcéose, or herpes virus (HHV-6 or HHV-7), been highlighted.
Towards a more appropriate treatment
These viruses, herpetic both are present in approximately 90% of the population but in a dormant state. They are entered in the organism, often asymptomatic, and have never been eliminated. It comes as the virus can reactivate, even after many years, which seems to be the case in these patients.
Coinciding with this viral reactivation, the immune system is on the alert: cytotoxic T lymphocytes (CD8 +) are activated and ready to destroy the infected cells. Whether in the blood, skin, liver or lungs, CD8 + lymphocyte populations detected have mostly the same receptor, which specifically recognizes a portion of the shell of the virus. In addition, large amounts of tumor necrosis factor α (TNF) and interferon-γ are secreted. The production of these two cytokines involved in inflammatory reactions, is particularly high among patients with more severe symptoms at the visceral level.
These results demonstrate that the immune response is not directed against the drug but against viruses reactivated. Thus, the drugs would be able to cause reactivation of latent virus in less certain, a fact which is not explained but will certainly be the subject of further research. Treatment of DRESS syndrome may therefore also evolve: corticosteroids and antiviral drugs may be administered to control inflammation and cons respectively against the herpes virus.
The Epstein-Barr virus, two viral particles are visible in this image taken with an electron microscope, is involved in the DRESS syndrome. © Wikimedia Commons
No comments:
Post a Comment