HTLV‐1‐associated infective dermatitis: updates on the pathogenesis

Abstract

HTLV-1-associated infective dermatitis (HAID) is the main paediatric manifestation of human T-cell lymphotropic virus type 1 (HTLV-1). It is characterised by a chronic exudative eczematous eruption and persistent infection with Staphylococcus aureus (SA) and beta-haemolytic streptococci (BHS). Prevalence is highest in the Caribbean and Brazil; however, cases have been reported in other HTLV-1 endemic regions. Approximately 20 million people worldwide are infected with HTLV-1 and only 5-10% suffer from disease. Other manifestations include adult T-cell leukaemia/lymphoma (ATLL) and tropical spastic paraparesis/HTLV-1-associated myelopathy (TSP/HAM). HAID may also progress to ATLL or TSP/HAM. Treatment options are limited to prolonged antibiotic therapy. The aim of this paper is to review existing evidence and propose new theories on the pathogenesis of HAID. The current view is that HTLV-1 infection is required and in susceptible individuals leads to immune dysregulation with subsequent immunosuppression and superinfection with SA and BHS. Evidence suggests that host, environment and genetic factors may play a causative role. Genetic factors within ethnic groups determine host immune response and carrier state or disease manifestation of HTLV-1 infection. Increased IgE levels may contribute to the SA and BHS superinfection in HAID. Additionally, the possible impact of filaggrin, skin proteinase dysregulation, Langerhans cell dysfunction and TH2 chemokines is highlighted. More than 45 years since the discovery of HAID, the exact pathogenesis is still not fully understood. Further research is still needed to clearly elucidate the exact pathogenic mechanism of HAID.

Privileged Structures Meet Human T-Cell Leukemia Virus-1 (HTLV-1): C2-Symmetric 3,4-Disubstituted Pyrrolidines as Nonpeptidic HTLV-1 Protease Inhibitors

“…Within the first subset of inhibitors (1−6) being varied only in P 1 /P 1 ′ position, a steady increase in affinity from the allylsubstituted derivative (1) via sterically more demanding allylic substituents (2 and 3) to the benzyl-substituted derivative (4) can be observed, the latter representing the most potent derivative of this subset with an affinity of 2.0 μM. However, the introduction of hydrophobic residues in the para-position of the benzyl moiety such as an iodo (5) or a CF 3 substituent (6) clearly reduces the affinity.…”

Recurrent Facial Erythema with Cytotoxic T Cell Infiltration as a Possible Reactive Eruption in a Human T-Cell Lymphotropic Virus Type 1 Carrier

“…HTLV-1-associated infective dermatitis is a chronic exudative eczematous eruption prevalent in children of the Caribbean area and South America [7]. This disease is seen in HTLV-1 carriers, and some of the patients develop HAM/TSP.…”

Human T-cell leukemia virus-associated malignancy

“…Characterized by ‘floaters’ and foggy vision in the eye, this condition is classified as an intermediate uveitis and can be the only symptom of HTLV-1 infection or associated with HAM/TSP [49]. Infective dermatitis associated with HTLV-1 (IDH) is a pediatric form of severe, recurrent eczema commonly associated with endemic HTLV-1 infection [50]. Importantly, IDH has been considered an indicator of future ATL or HAM/TSP development [51].…”