Rheumatoid arthritis and connective tissue disease are unexpectedly more likely in people with HIV taking potent anti-HIV therapy, suggests new research. Two studies of the subject - one from the UK and one from the US - were presented at last week’s American College of Rheumatology meeting in Washington.
Painful joints caused by rheumatic disease used to be common among people with severe HIV infection and AIDS before effective HIV therapy became available. Although potent HIV treatment has made HIV a more manageable disease there have been suggestions that the drugs could be associated with inflammatory diseases like arthritis in some patients.
In the UK study researchers from the Brighton and Sussex Medical School looked at a group of 1100 adults with HIV infection. Anyone suffering a musculoskeletal problem, for example joint pain, was referred to a specialist clinic run by a rheumatologist with an interest in HIV infection.
A total of 63 patients were referred to the clinic meaning that 5% of the population suffered a rheumatic symptom in a year - higher than expected (Walker-Bone 2006).
Ninety per cent of them were currently taking HIV therapy and only 3 people - just 0.5% - had never been treated with antiretovirals. The most common diagnosis was joint pain - or arthralgia - made in 14% of the people referred to the clinic. But 8% were diagnosed with rheumatoid arthritis or connective tissue diseases, a higher rate than expected.
Both conditions are termed autoimmune rheumatic diseases, meaning the immune system is incorrectly identifying the body’s own tissue - in this case joint tissue - as foreign and attacking it.
A separate US study looked at a different population - 888 people with HIV who had been admitted as an inpatient - so generally more immunocompromised. The found that just over 10% of patients had been diagnosed with a rheumatic disorder, joint or bone pain.
Again they found an unexpectedly high rate of autoimmune rheumatic diseases including rheumatoid arthritis (Yao 2006) among people taking HIV therapy.
Both sets of researchers suggest that the ability of antiretroviral drugs to repair the immune system may be leading to unwanted effects - such as this type of autoimmune disease.
It is already known that the rebuilding of the immune system seen after people start taking HIV treatment can trigger inflammatory reactions in some people. It is sometimes called immune reconstitution syndrome (IRS) and can be thought of as an “overreaction” of the newly reconstituted immune response.
Further research is needed to more closely study the effects HIV therapy might be having in those people who start to develop rheumatic conditions, say the authors.
Walker-Bone K et al. Rheumatic manifestations of human immunodeficiency virus (HIV) infection among a British cohort. American College of Rheumatology Annual Meeting, abstract 1566, 2006.
Yao Q et al. A retrospective analysis of rheumatic diseases of 888 inpatients with human immunodeficiency virus (HIV) in the HAART era at Capital Health System in Trenton. American College of Rheumatology Annual Meeting, abstract 1995, 2006.