A total of 1,931 small vials of a blood-clotting substance used by hemophiliacs has been recalled by the American Red Cross because one of the 20,000 donors whose plasma was used to make the substance is experiencing symptoms of AIDS.

A spokeswoman for the Red Cross said yesterday that Baltimore is one of 12 regional blood centers that received the recalled substance, but that none of the vials had been distributed to hospitals or physicians.

All bottles of the possibly contaminated substance received by the Baltimore office have been quarantined, the spokeswoman said. The contaminated batch was shipped to the blood centers in early August. No other area blood centers received supplies from the suspect batch.

Hemophiliacs are among the four groups that have a higher risk of getting acquired immune deficiency syndrone (AIDS), partly because they use blood-clotting factors concentrated from the blood of many donors, according to medical experts.

About 100 of nearly 6,300 cases of AIDS diagnosed in the United States since 1981 have been linked to transfusions of blood or blood products. Hemophiliacs usually receive injections of the substance, known as Antihemophilic Factor (AHF), about 40 times a year.

The Baltimore office serves Harford, Carroll, Anne Arundel and Baltimore counties, Baltimore City and York, Pa., Red Cross officials said.