New York, Mar 9 (IANS): Researchers have identified a gene that increases the risk of a severe and potentially life-threatening reaction to the commonly prescribed antibiotic vancomycin.

Vancomycin, used to treat serious and life-threatening bacterial infections, has been known to be a common antibiotic trigger for a severe reaction known as DRESS -- Drug Rash with Eosinophilia and Systemic Symptoms.

The genetic risk factors predisposing specific patients were not known yet.

The new study, led by researchers from the Vanderbilt University in the US, showed that vancomycin triggers DRESS only in people carrying specific variations in human leukocyte antigen (HLA) genes.

DRESS has been characterised by fever, widespread skin rash and internal organ damage.

Routine testing for HLA gene could improve patient safety and reduce unnecessary avoidance of other antibiotics, said the study published in the Journal of Allergy and Clinical Immunology.

Since many patients who develop DRESS are often exposed to multiple antibiotics and other drugs simultaneously, the team used a specific diagnostic test developed in their laboratories called gamma-interferon ELISpot.

ELISpot exposed patients' white blood cells to vancomycin and other concurrently administered antibiotics. This test enabled them to determine which drug was most likely causing DRESS.

"This test will be important in the clinical care of patients starting vancomycin and will prevent mortality and short and long-term complications," said Elizabeth Phillips, researcher at the varsity.

"This observation also represents significant progress as we zero in on the mechanisms of these life-threatening immune-mediated drug reactions," she said.