Impact of HIV co-infection on immunological biomarker profile of HTLV-1 infected patients.

The impact of HIV co-infection on the plasma immunological biomarker profile of HTLV-1 infected patients was evaluated. The plasma levels of leukotrienes and chemokines/cytokines were quantified by ELISA and Cytometric Bead Array. A total of 138 volunteers were enrolled and divided into two subgroups ("HTLV-1(+)HIV(-)" and "HTLV-1(+)(HIV(+)"), which were categorized according to the HTLV-1-associated neurological disease (AS, pHAM and HAM). Reference controls were BD and HIV mono-infected patients. HAM(+) exhibited higher CD4+ T-cell counts as compared to HIV+ mono-infected patients and lower HTLV-1 proviral load as compared to mono-infected HAM(-) patients. AS(+) exhibited higher levels of CysLT, CXCL8/IL-8 and lower levels of CCL5/RANTES as compared to AS(-). Increased levels of IL-6 and TNF with reduced levels of CXCL10/IP10 and CCL5/RANTES were observed in co-infected pHAM(+) as compared to mono-infected pHAM(-). HAM(+) patients revealed an increase in CXCL8/IL-8, CCL2/MCP-1, CXCL-10/IP-10, TNF and a decrease in IL-2 as compared to HAM(-) subgroup.

Flow cytometric-based protocols for assessing anti-MT-2 IgG1 reactivity: High-dimensional data handling to define predictors for clinical follow-up of Human T-cell Leukemia virus type-1 infection.

The present work provides an innovative methodological approach to assess the anti-HTLV-1 IgG1 reactivity with practical application in clinical laboratory. Serum from non-infected healthy controls (NI) and HTLV-1-infected patients, categorized as asymptomatic (AS), putatively progressing to HTLV-1 associated myelopathy/tropical spastic paraparesis - HAM/TSP (pHAM) or with clinical diagnosis of HAM/TSP (HT) were assayed in two-parallel flow cytometry platforms, referred as: Fix and Fix&Perm protocols. Operating-characteristics analysis indicated that a single pair of attributes ("serum dilution/cut-off") for Fix and Fix&Perm protocols presented excellent performance for the diagnosis of HTLV-1 infection. Conversely, Fix and Fix&Perm protocols displayed weak/moderate overall performances when applied with prognosis purposes of HTLV-1 infection. A panoramic snapshot provided by the reactivity boards revealed clearly the higher sensitivity of Fix&Perm protocol for detecting seropositivity for HT, suggesting that stepwise combinatory criteria would improve the global performance of using a single pair of attributes. Three data mining strategies were tested, including endpoint titer analysis, heatmap assemblage and decision tree analysis. Bi-dimensional heatmap analysis demonstrated that, while the clustering profile of NI vs HTLV-1+ revealed segregation in opposite poles, AS vs HT presented discrete segregation but still displaying an intertwined distribution pattern. The combination of methods for segregating AS from HT displayed a moderate but superior global accuracy (85.7%; LOOCV=71.4%). The comprehensive data analysis support that the combination of methods have improved the performance to the differential diagnosis of AS and HT, with direct association with laboratorial records, including serum cytokine levels and proviral load.

Immunological signature of the different clinical stages of the HTLV-1 infection: establishing serum biomarkers for HTLV-1-associated disease morbidity.

This study aimed at establishing the immunological signature and an algorithm for clinical management of the different clinical stages of the HTLV-1-infection based on serum biomarkers. A panel of serum biomarkers was evaluated by four sets of innovative/non-conventional data analysis approaches in samples from 87 HTLV-1 patients: asymptomatic carriers (AC), putative HTLV-1 associated myelopathy/tropical spastic paraparesis (pHAM/TSP) and HAM/TSP. The analysis of cumulative curves and molecular signatures pointed out that HAM/TSP presented a pro-inflammatory profile mediated by CXCL10/LTB-4/IL-6/TNF-α/IFN-γ, counterbalanced by IL-4/IL-10. The analysis of biomarker networks showed that AC presented a strongly intertwined pro-inflammatory/regulatory net with IL-4/IL-10 playing a central role, while HAM/TSP exhibited overall immune response toward a predominant pro-inflammatory profile. At last, the classification and regression trees proposed for clinical practice allowed for the construction of an algorithm to discriminate AC, pHAM and HAM/TSP patients with the elected biomarkers: IFN-γ, TNF-α, IL-10, IL-6, IL-4 and CysLT. These findings reveal a complex interaction among chemokine/leukotriene/cytokine in HTLV-1 infection and suggest the use of the selected but combined biomarkers for the follow-up/diagnosis of disease morbidity of HTLV-1-infected individuals.

Electrophysiological analysis shows dizziness as the first symptom in human T cell lymphotropic virus type-associated myelopathy/tropical spastic paraparesis.

Dizziness is a symptom in human T cell lymphotropic virus type-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and may occur due to vestibulospinal tract dysfunction. This tract can be assessed by an electrophysiological test called vestibular-evoked myogenic potential (VEMP). The aim was to correlate the result of VEMP generated by acoustic stimuli and dizziness in individuals with human T cell lymphotropic virus type 1 (HTLV-1)-asymptomatic infection and HAM/TSP. VEMP was recorded from the sternocleidomastoid muscle of 60 HTLV-1-negative adults (60±8 years) and 60 individuals infected with HTLV-1, 30 being asymptomatic (59±8 years) and 30 with HAM/TSP (59±8 years). In all groups, 90% of the participants were women. VEMP was generated by acoustic stimuli (short tone bursts), with an intensity of 118 dBHL and band-pass filter from 10 Hz to 1,500 Hz, and presented 200 stimuli at a frequency of 1,000 Hz with a record time of 60 ms. Of 60 HTLV-1-negative individuals, 14 (23%) reported dizziness; VEMP was normal in all. In the HTLV-1-asymptomatic group, 11(37%) complained of dizziness (p=0.31); VEMP was altered in four (40%) subjects with dizziness and in one (5%) without dizziness (p=0.00). In the group with HAM/TSP, dizziness was reported by 17 (57%) subjects (p=0.002); VEMP was altered in 11 (64%) with dizziness and in 5 (38%) without dizziness (p=0.15). Dizziness without an apparent etiology in HTLV-1-asymptomatic carriers deserves attention in terms of a possible subclinical spinal cord involvement that can be clarified through spinal electrophysiological tests. Damage of the vestibulospinal tract seems to occur in the early stages of HAM/TSP.

Proviral load and the balance of serum cytokines in HTLV-1-asymptomatic infection and in HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP).

This study compared the proviral load and the plasma cytokine profiles (interleukin-IL-2, IL-4, IL-6, IL-10, TNF-α, IFN-γ) in 87 HTLV-1-infected individuals, including 28 with HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), 32 with possible pHAM/TSP and 27 asymptomatic carriers (AC). The control group was composed by 21 HTLV-1-seronegative individuals. Our finding demonstrated that HAM/TSP group presented higher proviral load as compared to all other HTLV-1 groups (p<0.0001). The HAM/TSP group showed higher serum concentration of IL-6 (p=0.0009) as compared to all other groups. Moreover, higher serum concentration of IFN-γ (p=0.0118) and IL-4 (p=0.0166) were observed in HAM/TSP group as compared to the healthy controls. Additionally, the HAM/TSP group also showed higher serum concentration of TNF-α (p=0.0239) and IFN-γ (p=0.0118) as compared to AC. No differences in the serum concentration of IL-2 and IL-10 were observed among the groups. The analysis of cytokine balance demonstrated that HAM/TSP presented higher pro-inflammatory profile with enhanced IFN-γ/IL-10 and IFN-γ/IL-4 ratio as compared to AC and pHAM/TSP. Further analysis pointed out to a positive correlation between the IFN-γ response and the proviral load in AC. Conversely, a negative association between TNF-α and IL-2 with the proviral load was the hallmark of HAM/TSP group. These findings suggested that the proviral load and the pro-inflammatory cytokine profile may be independent events in the peripheral blood of HAM/TSP individuals. The knowledge about the existence of individual virological/immunological behavior upon HTLV-1 infection, may guide to the establishment of more effective therapeutic interventions.