Higher Human T-Lymphotropic Virus Type 1 Subtype C Proviral Loads Are Associated With Bronchiectasis in Indigenous Australians: Results of a Case-Control Study

Abstract

In this case-control study, HTLV-1 infection increased risk of bronchiectasis 1.84 times. HTLV-1 proviral loads for bronchiectasis patients were significantly higher than those of controls. HTLV-1 proviral loads correlated with the extent of radiologically determined pulmonary injury.

Geographic variation in the aetiology, epidemiology and microbiology of bronchiectasis

“…These data however do not elucidate whether viruses are a cause or consequence of exacerbations, an area for future investigation. Despite this, recent work from both Europe and the Asia-Pacific has indicated a potential role for human T-lymphotropic virus type 1 (HTLV-1) mediated inflammation in the causation of bronchiectasis [109,110]. A separate New Zealand based study similarly proposed adenovirus infection as a potential cause of post-infectious bronchiectasis (Fig.…”

A Multiplex Droplet Digital PCR Assay for Quantification of HTLV-1c DNA Proviral Load and T-Cells from Blood and Respiratory Exudates Sampled in a Remote Setting

“…A higher HTLV-1 proviral burden resides in cells extracted from BAL samples compared with peripheral blood, and suggests differences in the location of the HTLV-1 inflammatory response. In fact, measurement of specific compartments such as the lungs may be a better indicator for risk of disease progression, specifically HTLV-1c-associated respiratory diseases such as bronchiectasis [11].…”

“…Human T-cell leukemia virus type 1 (HTLV-1) is a lymphoproliferative and ultimately oncogenic retrovirus that primarily infects CD4 + T-cells [3] and is the causative agent of adult T-cell leukemia/lymphoma, HTLV-1-associated myelopathy/tropical spastic paraparesis [4, 5] and various other immune-mediated disorders [6-10]. In remote Australia, HTLV-1 infections are most significantly associated with bronchiectasis and multiple blood stream bacterial infections [2, 11, 12]. The HTLV-1 viral DNA burden is measured as the proviral load (PVL), which is the proportion of peripheral blood mononucleated cells (PBMCs) carrying an integrated copy of the HTLV-1 viral DNA.…”

Infection with human retroviruses other than HIV-1: HIV-2, HTLV-1, HTLV-2, HTLV-3 and HTLV-4

“…By order of strength of association these conditions are: intermediate uveitis, infective dermatitis, myositis (polymyositis or inclusion body myositis), arthritis, infiltrative lung disease and invasive cervical carcinoma (TABLE 3). Recently an association has been reported between HTLV-1 infection and bronchiectasis in Indigenous Australians, leading to a higher risk of lower respiratory tract infections [107].…”