In a recent study entitled “High prevalence of bronchiectasis is linked to HTLV-1-associated inflammatory disease,” a team of researchers analyzed whether the human T-lymphotropic virus type-1 (HTLV-1), the agent responsible for several human diseases, including adult T-cell leukemia/lymphoma, is associated with pulmonary conditions, specifically bronchiectasis. The study was published in the journal BMC Infectious Diseases.
The human T-lymphotropic virus type-1 (HTLV-1) is the causative agent of adult T-cell leukemia/lymphoma (ATLL), HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and HTLV-1-associated uveitis. However, the list of diseases linked to HTLV-1 is likely to increase and include polymyositis, arthropathy, Sjögren’s syndrome (keratoconjunctivitis sicca), thyroiditis and infective dermatitis.
Notably, the association of HTLV-1 infection with respiratory syndromes, such as bronchiectasis, is considerably less recognized. In this new research, authors hypothesized that if HTLV-1 is associated with an increased risk of bronchiectasis (a disease characterized by a permanent enlargement of parts of the airways of the lung, with symptoms including chronic cough with mucus production, shortness of breath and chronic pain), it would be detectable in patients with high levels of HTLV-1 pro-viral load (VL). To this end, authors performed a retrospective case review study where they analyzed a 464 HTLV-1 seropositive patients attending the National Centre for Human Retrovirology, St Mary’s Hospital in London between 1993 and 2012. The team registered HTLV-1 patients either as symptomatic patients (SP) or as asymptomatic carriers (ACs). The SPs had HTLV-1-associated diseases, such as ATLL; strongyloidiasis; HAM/TSP; or other HTLV associated inflammatory disease (HAID) — polymyositis, uveitis and arthritis.
The team found that bronchiectasis is common in HTLV-1 infected individuals in the UK (3.4 %) and it occurs in higher levels when compared to the general population (0.1 %). Specifically, they found a positive bronchiectasis diagnosis determined by CT scanning in 1 Ac individual and 13 SPs. Additionally, the team observed that Non-African/Afro-Caribbean patients with pre-existing HTLV-1-associated disease have a higher risk. In agreement with authors’ hypothesis, HTLV-1 viral load was significantly higher in patients with symptomatic HTLV-1 infection than in the ACs.
In light of their results, authors emphasize that it is important to screen symptomatic HTLV-1 patients for pulmonary disease (through radiological imaging) soon after HTLV-1 diagnosis via CT scanning. Additionally, they suggest that bronchiectasis should also be considered a HTLV-associated disease and levels of HTLV should be measured in patients with unexplained bronchiectasis.