Human T-cell lymphotropic virus type I (HTLV-I) proviral DNA viral load among asymptomatic patients and patients with HTLV-I-associated myelopathy/tropical spastic paraparesis

Montanheiro, Patrícia; Oliveira, Augusto César Penalva de; Vergara, María Paulina Posada; Milagres, Antonio C.P.; Tauil, Carlos Bernardo; Marchiori, Paulo Eurípedes; Duarte, Alberto J. S.; Casseb, Jorge

doi:10.1590/s0100-879x2005001100011

Cited by 63 publications

(51 citation statements)

References 19 publications

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“…In addition, our triplex assay was validated with a much broader range of HTLV-infected samples, including a wide variety of HTLV genotypes and subtypes together with PBMC samples obtained from individuals with diverse HTLV-1-associated clinical manifestations. We were thus able to assess the difference in PVL according to disease manifestation: the median PVL in ATLL and HAM/TSP patients was significantly higher than that in ACs, a finding consistent with previous publications (11,18,22,30,36,39).…”

Section: Discussionsupporting

confidence: 88%

Development and Validation of a Multiplex Real-Time PCR Assay for Simultaneous Genotyping and Human T-Lymphotropic Virus Type 1, 2, and 3 Proviral Load Determination

et al. 2009

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The human T-lymphotropic virus (HTLV) proviral load remains the best surrogate marker for disease progression. Real-time PCR techniques have been developed for detection and quantification of cosmopolitan HTLV type 1a (HTLV-1a) and HTLV-2. Since a growing level of diversity in subtypes and genotypes is observed, we developed a multiplex quantitative PCR for simultaneous detection, genotyping, and quantification of proviral loads of HTLV-1, 2, and 3. Our assay uses tax type-specific primers and dually labeled probes and has a dynamic range of 10 5 to 10 HTLV copies. One hundred sixty-three samples were analyzed, among which all of the different subtypes within each HTLV genotype could be detected. The performance of proviral load determination of our multiplex assay was compared with that of a previously published HTLV-1 singleplex quantitative PCR based on SYBR green detection, developed at a different institute. Linear regression analysis showed a statistically significant (P < 0.0001) and strong (r 2 ‫؍‬ 0.87) correlation between proviral load values measured with the two distinct real-time PCR assays. In conclusion, our novel assay offers an accurate molecular diagnosis and genotyping, together with the determination of the proviral load of HTLV-infected individuals, in a single amplification reaction. Moreover, our molecular assay could offer an alternative when current available serological assays are insufficient.Since the discovery of human T-lymphotropic virus type 1 (HTLV-1) in 1980 (16, 40), three other genotypes and 10 subtypes have been recognized. The precise geographical distribution and the clinical consequences of these infections are still a matter of debate. This can be attributed at least in part to the fact that there are insufficient accurate tools for HTLV diagnosis, genotyping, and measurement of viral burden.HTLV-1 is endemic in several geographical areas, including sub-Saharan Africa, South America, the Caribbean Islands, Japan, and Melanesia. It has been estimated that worldwide 10 to 25 million people are infected with this retrovirus (41, 53). Most HTLV-1-infected individuals remain asymptomatic throughout their lifetimes. However, 5 to 10% of infected people develop clinical complications, among which adult Tcell leukemia/lymphoma (ATLL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) are the most severe. Other manifestations of HTLV-1 infection include infective dermatitis (25), uveitis (34), arthritis (38), and Strongyloides stercoralis infection (53). Some of these manifestations could accelerate disease development and/or progression (12, 16). For HTLV-1, a distinction is made between seven subtypes: the worldwide, cosmopolitan subtype HTLV-1a; the Central African subtypes HTLV-1b, -d, -e, -f, and -g; and the Australo-Melanesic subtype 23,41,52).HTLV-2 was discovered in 1982. This retrovirus is endemic in Amerindian and pygmy populations and epidemic in intravenous drug users (16,49). In contrast to the case for HTLV-1, convincing epidemiological demonstra...

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Section: Discussionsupporting

confidence: 88%

Development and Validation of a Multiplex Real-Time PCR Assay for Simultaneous Genotyping and Human T-Lymphotropic Virus Type 1, 2, and 3 Proviral Load Determination

et al. 2009

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“…The HTLV-1 proviral load was quantified by real-time PCR using TaqMan probes for the pol gene in two million PBMCs. The albumin gene was the internal genomic control and MT2 cells were used as positive controls [Montanheiro et al, 2005]. Amplification and data acquisition were carried out using the I-cycler Sequence Detector System (BioRad, Hercules, CA).…”

Section: Methodsmentioning

confidence: 99%

“…Amplification and data acquisition were carried out using the I-cycler Sequence Detector System (BioRad, Hercules, CA). The normalized value of the HTLV-1 proviral load was calculated as the ratio of HTLV-1 DNA average copy numbers/albumin DNA average copy numbers Â 2 Â 10 6 and expressed as the number of HTLV-1 copies/ 10 4 PBMC [Montanheiro et al, 2005]. After giving informed consent, patients underwent a neurological assessment by a neurologist blinded to their HTLV status.…”

Section: Methodsmentioning

confidence: 99%

Presence of tropical spastic paraparesis/human T‐cell lymphotropic virus type 1‐associated myelopathy (TSP/HAM)‐like among HIV‐1‐infected patients

Casseb

Oliveira

Vergara

et al. 2008

Journal of Medical Virology

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A total of 38 HIV-1/HTLV-1 co-infected subjects were identified in this cohort: Twenty-six had already been diagnosed with AIDS and 12 remained asymptomatic. Six of 38 co-infected subjects (18%) were diagnosed as having TSP/HAM and also AIDS, and for 5 of them TSP/HAM was their first illness. One additional incident case was diagnosed after 2 years of follow-up. No modifications on HIV-1 viral load was seen. In contrast, the co-infected with TSP/HAM-like group showed higher HTLV-1 proviral load (505 +/- 380 vs. 97 +/- 149 copies/10(4) PBMC, P = 0.012) than asymptomatic co-infected subjects, respectively. The incidence of myelopathy among HIV-1/HTLV-1 co-infected subjects is probably higher than among patients infected only with HTLV-1, and related to a higher HTLV-1 proviral load. Thus, HTLV-1/2 screening should be done for all HIV-1-infected patients in areas where HTLV-1 infection is endemic.

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“…Alta carga proviral de HTLV-1 em células sangüíneas periféricas tem sido associada com alto risco para doenças neurológicas 24 . No caso do HTLV-2, um número significativo de linfócitos infectados pode contribuir para acelerar a imunodeficiência e aumentar o risco de neuropatia em indivíduos co-infectados com HIV-1 18 .…”

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Carga proviral do HTLV-1 e HTLV-2: um método simples através da PCR quantitativa em tempo real

Tamegão-Lopes

Rezende

Maradei-Pereira

et al. 2006

Rev. Soc. Bras. Med. Trop.

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RESUMOOs vírus linfotrópicos de células T humanas, quando integrados ao genoma da célula hospedeira, provírus, têm como marcador de replicação seu DNA proviral. A carga proviral parece ser um importante fator no desenvolvimento de patologias associadas a estes retrovírus. Neste estudo foi desenvolvida uma metodologia para quantificação absoluta da carga proviral dos HTLV-1 e HTLV-2 através da PCR em tempo real. Cinqüenta e três amostras de doadores de sangue com teste de ELISA reagente foram submetidas à metodologia, que utilizou o sistema TaqMan ® para três seqüências alvo: HTLV-1, HTLV-2 e albumina. A quantificação proviral absoluta foi determinada através da proporção relativa entre o genoma do HTLV e o genoma da célula hospedeira, levando em consideração o número de leucócitos. O método apresentado é sensível (215 cópias/mL), prático e simples para quantificação proviral, além de eficiente e adequado para confirmação e discriminação da infecção pelos tipos virais. Palavras-chaves: HTLV. PCR quantitativa em tempo real. Carga proviral do HTLV. ABSTRACTWhen the human T cell lymphotropic virus (HTLV) is integrated with the host cell genome (provirus), its proviral DNA is a replication marker. Proviral load appears to be an important factor in the development of diseases related to these retroviruses. In this study, a methodology for absolute quantification of the HTLV-1 and HTLV-2 proviral load using real-time PCR was developed. Fifty-three blood donor samples with positive ELISA test result were subjected to this methodology, which utilized the TaqMan ® system for three target sequences: HTLV-1, HTLV-2 and albumin. The absolute proviral load was quantified using the relative ratio between the HTLV genome and the host cell genome, taking into consideration the white blood cell count. The method presented is sensitive (215 copies/ml), practical and simple for proviral quantification, and is efficient and appropriate for confirming and discriminating infections according to viral type. Key-words: HTLV. Quantitative real-time PCR. HTLV proviral load. Os vírus linfotrópicos de células T humanas (HTLV-1

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Human T-cell lymphotropic virus type I (HTLV-I) proviral DNA viral load among asymptomatic patients and patients with HTLV-I-associated myelopathy/tropical spastic paraparesis

Cited by 63 publications

References 19 publications

Development and Validation of a Multiplex Real-Time PCR Assay for Simultaneous Genotyping and Human T-Lymphotropic Virus Type 1, 2, and 3 Proviral Load Determination

Development and Validation of a Multiplex Real-Time PCR Assay for Simultaneous Genotyping and Human T-Lymphotropic Virus Type 1, 2, and 3 Proviral Load Determination

Presence of tropical spastic paraparesis/human T‐cell lymphotropic virus type 1‐associated myelopathy (TSP/HAM)‐like among HIV‐1‐infected patients

Carga proviral do HTLV-1 e HTLV-2: um método simples através da PCR quantitativa em tempo real

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