39% individuals may have antibodies against common gene therapy vector – AAV

A small study of 323 patients in the UK has found that 39% of them have antibodies known to be causing complications in gene therapy procedures.

AAV – adeno-associated virus – is common vector used to deliver gene editing molecules into cells inside human body. The virus is in principle harmless. However, in specific cases there is possibility of adverse reaction leading even to death. A history of gene therapies painfully experienced toxic reacton to AAV in 1999 as death of Jesse Gelsinger freezed whole clinical approach.

Body’s immune system reaction to AAV depends on previous exposition to adenoviruses. Presence of AAV antibodies is one of the indications of possible complications during gene therapy.

The study points to a variation of AAV antibodies level in relation to age: 36% of infants had antibodies, 7% of primary school children, and then 54% within adults. Overall average was 39%. The variations indicate that paediatric patients might have different responses in groups spanning only a few years, as they go from 5/14 through 1/14 to 8/14 of anti-AAV phenotype.

More: “Age-related seroprevalence of antibodies against AAV-LK03 in a UK population cohort”, D. Perocheau et al., 2018, doi:10.1089/hum.2018.098.