Human Immunodeficiency Virus
Human Immunodeficiency Virus (HIV) has high prevalence in many parts of the world; in 2014 (WHO data), 2.6 million children were estimated to be living with HIV and over 90% living in Sub-Saharan Africa. HIV is associated with increased rates of musculoskeletal and rheumatic manifestations: arthritis is a common presenting feature of HIV infection (70% of cases).
- An acute sero-conversion illness is associated with arthralgia, fever, rash, lymphadenopathy and flu-like symptoms.
- Persistent or chronic HIV arthritis occurs with a spectrum of clinical patterns.
- Spondyloarthropathy: the reported prevalence of this type of arthritis increased in Africa with the HIV pandemic despite a low prevalence of HLA-B27; this is more common in boys with lower limb arthritis and associated with spondylitis, sacroiliitis, enthesitis and anterior uveitis (painful red eye).
- Polyarthritis is well described in adults with HIV but less so in children. Oligoarticular arthritis is not uncommon but monoarthritis, especially in the large joints such as hip and knee, should raise suspicion of Tuberculosis (TB) arthritis which commonly co-exists with HIV infection.
- Psoriasis, dactylitis and nail dystrophy with asymmetrical large and small joint involvement are common feature of HIV related arthritis.
- Auto-antibodies are common and may relate to immune dysregulation with polyclonal activation of B-cells and hypergammaglobulinaemia. Rheumatoid Factor (RF), Anti-Citrullinated Peptide Antibodies (ACPA), Anti-Nuclear Antibody (ANA) and Anticardiolipin antibodies (ACLA) are observed irrespective of clinical features of rheumatic disease and their interpretation can be challenging in the context of differential diagnosis.
- Severe untreated HIV arthropathy can lead to joint contractures and disability.
- Uveitis is a feature associated with HIV arthritis and can be a painful red eye or asymptomatic (rather like JIA related uveitis).
- Bone and joint infection are more common and the spectrum of organisms is different; streptococcal infections are more common than staphylococcal infection. Infection with TB must always be considered, especially with monoarthritis and chronic musculoskeletal pain.
- Radiographs are usually normal in HIV arthritis. Evidence of joint damage is helpful in the differential diagnosis (infection and especially TB, avascular necrosis, malignancy).
- Radioisotope bone scans may be useful in excluding bone and joint infection and avascular necrosis.
- Specialist assessment is needed to confirm the diagnosis, exclude other differential diagnoses and screen for co-existent infections.
- With HIV infection there is also increased susceptibility to infections such as TB and enteropathic organisms associated with arthritis.
- The treatment for HIV arthritis involves Anti-Retroviral Therapy (ART) - Protease Inhibitors (e.g., Indinavir) - which have markedly improved the outcome of HIV.
- Most children with HIV arthropathy respond to ART; symptoms resolve within weeks or months. NSAIDs provide symptom relief and intra-articular corticosteroids are helpful with oligo-articular disease and as bridging agents whilst starting ART or other immunosuppressive treatments. Chloroquine has anti-retroviral effects (in-vitro studies) and is often used in the treatment of HIV arthropathy.
- In resistant cases, treatment approaches are similar to those used for JIA but such treatments must only be given under specialist guidance due to the infection risk (especially TB); CD4 counts and HIV viral loads are important in assessing the severity of HIV infection as well as monitoring of ART and immunosuppression. Clinical trials and outcome studies are needed to inform clinical practice.
- ART may paradoxically also induce musculoskeletal symptoms; ART associated myositis (with raised creatine kinase enzymes) is reported as is arthralgia, monoarthritis, avascular necrosis.