Prevalence of HTLV type I infection in Iran: a serological and genetic study

Immigrating and vicinity are not risk factors in the prevalence and transmission rate of human T-lymphotropic virus type 1: A Survey in an endemic region of Iran and Afghan refugees

Human T-lymphotropic virus type 1 (HTLV-1) is a retrovirus associated with two life-threatening diseases; HAM/TSP and ATLL. Due to the slow-growing HTLV-1 infection worldwide, WHO urged for elimination. A large border with Afghanistan, northeast Iran is an endemic region for HTLV-1 infection. Historically, Afghanistan has common sociocultural similarities to Persian peoples. This study was conducted to evaluate HTLV-1 prevalence in Afghan refugees. Also, the HTLV-1 transmission rate and understanding of whether or not the Silk Road has been the route of HTLV-1 infection to Iran were investigated. This case-control study was conducted in a rural area of Fariman city, with Afghan residents who migrated around 165 years ago, from 1857, the Treaty of Paris at the end of the Anglo-Persian war, and a refugee camp in Torbat-e-Jam city. These populations in HTLV-1 endemic area were compared to a segregated population of Afghan refugees in Semnan, the centre of Iran. Blood samples of 983 volunteers were assessed with the ELISA method for the presence of HTLV-1 antibodies and then confirmed by PCR technique. All samples from Afghan refugee camps, Semnan and Torbat-e-Jam, were negative for HTLV-1 infection. However, the prevalence of HTLV-1 infection in Fariman, a rural population of Afghan origin, was approximately 2.73%. The results showed that HTLV-1 is not endemic in Afghanistan, a war-stricken region with refugees distributed worldwide. The land Silk Road has not been the route of HTLV-1 transmission to Northeastern Iran. Importantly, HTLV-1 endemicity might occur during a long time of living in an endemic area.

Updates on the Epidemiology of the Human T-Cell Leukemia Virus Type 1 Infection in the Countries of the Eastern Mediterranean Regional Office of the World Health Organization with Special Emphasis on the Situation in Iran

Background: The epidemiology and prevalence of the Human T-cell leukemia virus type-1 (HTLV-1) infection represent a recommended priority by global health agencies. An in-depth revision to update the status of this infection in countries including those of the Eastern Mediterranean Regional Office (EMRO) of the World Health Organization is hence required. Methods: Ninety-seven studies evaluating the HTLV-1 infection in low- and high-risk populations in EMRO countries were retrieved from the international electronic databases and were used to assess the epidemiological status of the infection in these countries. Results: Most epidemiologic reports were published from Iran, with more than 50% of Iranian prisoners and around 4% of healthy individuals reported to have the infection. In Egypt, a considerable prevalence of the virus spans around 1.11% of blood donors. Foci of HTLV-1 infection are also present in some countries and require a careful epidemiological evaluation. In the other EMRO countries, a lower prevalence that does not exceed 1% was reported. Conclusion: The epidemiology and prevalence of HTLV-1 in the EMRO countries require a tight revision and update. Published studies reveal a scarce distribution of the virus in the African countries of EMRO, while a lower prevalence is denoted in the Asian countries of EMRO, except in Iran, where the prevalence is high.

Epidemiology of blood-borne viral infections in Afghanistan

Although a few studies have been done on transmissible blood-borne viral infections in high-risk groups, little attention has been given to assessing the infection status of the general population in Afghanistan. To investigate the epidemiological status in the general population, we tested the serological markers of hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis delta virus (HDV), human immunodeficiency virus 1 (HIV-1) and human T-cell leukemia virus (HTLV) infections. In total, 492 samples were selected randomly from Nangarhar, Herat, Mazar-e Sharif, Kandahar, and Kabul from subjects between 25 and 70 years old. The samples were tested for the presence of HBsAg, anti-HBs, anti-HBc, anti-HDV, anti-HCV, anti-HIV-1 and anti-HTLV I/II antibodies using chemiluminescent immunoassays on Abbott Architect automated platforms. In addition, 220 HBsAg-positive samples identified among 5897 samples from the general population of the same regions of Afghanistan were included in the study and tested for both HBsAg and anti-HDV to investigate HDV prevalence in the country. Viral loads of HBV, HCV and HDV were determined in all seropositive samples using Ampliprep/Cobas TaqMan HBV, HCV, Test Roche (CA, USA), and an in-house method, respectively. Out of 492 samples, 31 (6.3%), 136 (27.6%) and 149 (30.3%) were found to be positive for HBsAg, anti-HBs and anti-HBc, respectively. Anti-HDV positivity was detected in five (2.1%) out of 234 HBsAg-positive samples (including 14 of the randomly selected samples that were not among the 220 previously identified as HBsAg positive). Only eight out of 492 (1.6%) subjects were positive for anti-HCV antibodies. Seven out of 489 (1.4%) were positive for anti-HIV-1 antibodies, and three out of 466 cases (0.6%) were positive for anti-HTLV I/II antibodies. These results suggest that Afghanistan is an intermediate endemic region for HBV, HDV and HCV infection. The prevalence of HIV-1 seems to be significantly higher than the global prevalence and that of the eastern Mediterranean region. In addition, the HTLV I/II screening results suggest that these viruses should be monitored in Afghanistan to confirm the trend observed in the current study.

Epidemiology of human T-lymphotropic virus type 1 among blood donors and general population in Iran: a meta-analysis

Aim: The present meta-analysis aims to assess the epidemiology of human T-lymphotropic virus type 1 (HTLV-1) among blood donors and general population in Iran. Methods: The present study was designed according to PRISMA guidelines. Results: The prevalence of HTLV-1 in 34 studies with a sample size of 3,626,364 blood donors was 0.20% (95% CI: 0.15–0.26) and the prevalence of this virus among men and women blood donors was 0.20% (95% CI: 0.15–0.27) and 0.64% (95% CI: 0.13–3.01), respectively and the female-male odds ratio was 3.13 (1.35–7.25, p = 0.008). In five studies consisting of 4763 individuals, the prevalence of HTLV-1 among the general population who lived in the main HTLV-1 endemic regions (Khorasan provinces, in northeastern Iran) was 2.5% (95% CI: 1.3–4.7) and the prevalence of this virus among men and women was 2.4% (95% CI: 0.8–7.1) and 3.4% (95% CI: 2.0–5.7), respectively. According to the systematic review, the prevalence of HTLV-1 in general population living in non-endemic regions of HTLV-1 was reported to be 0.07% to 1.8%. Conclusion: Considering the high prevalence of HTLV-1 in the main HTLV-1 endemic regions of Iran, persistent prevention programs are required in blood transfusion centers in these regions.

Prevalence and phylogenic study of human T-lymphotropic virus 1 in patients with thalassemia in the northeast of Iran

Aim: This study aimed to investigate the frequency and phylogenetic distribution of human T-lymphotropic virus type 1 (HTLV-1) in thalassemia cases. Methods: Between 2006 and 2013, a total of 100 thalassemic individuals were investigated for HTLV-1 infections. Results: Four people (4%) were reactive for HTLV antibodies. No considerable correlation was seen between factors such as age, blood transfusion history, surgery, marital status, gender and blood types. All HTLV-1 sequences belonged to the transcontinental (A) subgroup in the cosmopolitan (a) subtype. Conclusion: In addition to phylogenetic distribution, our results demonstrate that the prevalence of HTLV-1 infection among thalassemia patients in Mashhad is higher than that of previous studies.

Prevalence and phylogenetic analysis of HTLV-1 in a segregated population in Iran

Human T-lymphotropic virus type 1 (HTLV-1) infection is an important health issue that affects a variety of endemic areas. The Khorasan province, mainly its capital Mashhad in northeastern Iran, was reported to be as one of these endemic regions. Torbat-e Heydarieh, a large city Southwest border to Mashhad with a segregated population was investigated for the prevalence and associated risk factors of HTLV-1 infection in 400 randomly selected individuals. Blood samples were tested for the presence of HTLV-1 antibodies via the ELISA method and then were confirmed by an Immunoblot test. For the presence of HTLV-1 in lymphocytes of infected subjects, PCR was performed on LTR and TAX regions. DNA sequencing of LTR fragment was also carried out to determine the phylogenetic of HTLV-1, using the Maximum likelihood method. HTLV-1 sero-reactivity (sero-prevalence) among the study population was 2% (8/400), of which 1.25% had HTLV-1 provirus in lymphocytes (actual prevalence). HTLV-1 infection was significantly associated with the age, marital status, and history of blood transfusion (P < 0.05). However, there were no statistical differences between HTLV-1 infection, and gender, surgery, and hospitalization. In regression analysis, age showed the most significant correlation with the infection (P = 0.006, OR = 4.33). Based on our phylogenetic study, the HTLV-1 prevalent sequence type of Torbat-e Heydarieh belongs to the cosmopolitan subtype A. HTLV-1 prevalence in Torbat-e Heydarieh (1.25%) is low comparing to those of both Mashhad (2-3%) and Neishabour (3.5-5%) in the province of Khorasan. Thus, traveling mobility and population mixing such as marriage, bureaucratic affairs, occupation, and economic activities could be the usual routs of HTLV-1 new wave of spreading in this segregated city.

Seroepidemiology of human T-cell lymphotropic virus among Iranian adult thalassemic patients

BACKGROUND

A large number of transfusion-dependent thalassemic patients is at a substantial risk for transfusion-transmitted infections. Human T-cell lymphotropic virus (HTLV) is a blood-borne pathogen and can be transmitted via cellular products. We aimed to evaluate the seroprevalence of HTLV in transfusion-dependent thalassemic patients referred to Tehran Adult Thalassemia Clinic.

METHODS

From 2008 to 2010, 257 transfusion-dependent thalassemic patients who referred to Tehran Adult Thalassemia Clinic were enrolled. The seroprevalence of HTLV, hepatitis B virus (HBV), hepatitis C virus (HCV), and HIV were assessed using enzyme-linked immunosorbant assay (ELISA). Also, the samples with positive result for anti-HTLVAb (by ELISA) were reassessed using Western blot for HTLV.

RESULTS

Among the 257 transfusion-dependent thalassemic patients who were tested for anti-HTLVAb, 29 (11.3%, 95% CI = 7.8-15.6%) were found to be anti-HTLVAb positive by ELISA and Western blot. No case was detected to be HBsAg positive, whereas 16% had HBV seroconversion criteria, and more than 95% had anti-HBsAb in their sera. Also, 103 (40.1%) patients were HCV seropositive, 13 (5.1%) patients of which were co-infected with HCV/HTLV. Among the HTLV-infected patients, 44.8% were co-infected with HCV, whereas 39.5% of HTLV-seronegative individuals were HCV mono-infected (P > 0.05).

CONCLUSION

This study showed that transfusion-dependent thalassemic patients were in higher risk for transmission of different blood-borne pathogens such as HTLV. The screening of HTLV in Iranian blood donors is recommended.

Characterization of overt and occult hepatitis B virus infection among HTLV-1 positive healthy carriers in the Northeast of Iran; AN HTLV-I endemic area

To date, no studies have provided data on hepatitis B virus (HBV) prevalence among asymptomatic, healthy human T-lymphotropic virus (HTLV-I) positive carriers. This sero- and molecular epidemiology study was performed on patients in the Northeast of Iran, which is an endemic area for HTLV-I infection. A total of 109 sera were collected from HTLV-I positive healthy carriers who were admitted to Ghaem Hospital, Mashhad City. All were tested for HBV serology and subsequently, real time PCR was carried out on the samples, regardless of the results of the serology. Standard PCR and direct sequencing were applied on positive samples. All cases were negative for HBsAg, Anti-HBc, and anti-HBs were positive in 34 (31.1%), and 35 (32%) individuals, respectively. There were 19 (17.4%) cases that were positive only for anti-HBs, and they had already received HBV vaccine. 16 (15%) were positive for both anti-HBs and anti-HBc, indicating a past-resolved HBV infection. 18 (16.5%) were isolated as anti-HBc, and 56 (51.3%) were negative for all HBV serological markers. Only one subject (0.9%) had detectable HBV DNA (2153 copy/ml), and assigned as being an occult HBV infection. The low prevalence of HBsAg, despite the high percentage of anti-HBc positive cases, might be related to the suppression effect of HTLV-I on surface protein expression. The low prevalence of HBV infection among HTLV-I positive healthy carriers from an endemic region, indicates that the epidemiology of HTLV-I and HBV coinfection is related to the endemicity of HBV in that region, rather than HTLV-I endemicity.

Clinical features of HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) in northeast Iran

This study aimed to introduce clinical manifestations of patients in northeast Iran with HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and describe the epidemiological features, as well as risk factors for HTLV-1 infection. This is a cross-sectional study of HTLV-1 infected cases and HAM/TSP patients referred by outpatient neurology clinics as well as Mashhad Blood Transfusion Center from 2005 to 2010. The study comprises 513 cases, including 358 healthy carriers (HCs) and 145 HAM/TSP patients. The majority of carriers were male (73.5%), whereas 67.6% of HAM/TSP sufferers were female (P < 0.001). The mean age of HAM/TSP patients and HCs was 45.9 ± 13.6 and 39.5 ± 11.58 years, respectively (P < 0.001). The history of transfusion, surgery, hospitalization and cupping was observed in a significant greater number of HAM/TSP patients than the HCs (P < 0.001, P < 0.001, P < 0.001 and P = 0.029, respectively). Gait disturbance was the most common complaint in HAM/TSP patients (72.4%). This research develops an HTLV-1 data registry in an endemic area such as Mashhad which can serve useful purposes, including evaluation of clinical and laboratory characteristics of HAM/TSP patients and epidemiological data of HTLV-1-infected cases.

Epidemiological Aspects and World Distribution of HTLV-1 Infection

The human T-cell leukemia virus type 1 (HTLV-1), identified as the first human oncogenic retrovirus 30 years ago, is not an ubiquitous virus. HTLV-1 is present throughout the world, with clusters of high endemicity located often nearby areas where the virus is nearly absent. The main HTLV-1 highly endemic regions are the Southwestern part of Japan, sub-Saharan Africa and South America, the Caribbean area, and foci in Middle East and Australo-Melanesia. The origin of this puzzling geographical or rather ethnic repartition is probably linked to a founder effect in some groups with the persistence of a high viral transmission rate. Despite different socio-economic and cultural environments, the HTLV-1 prevalence increases gradually with age, especially among women in all highly endemic areas. The three modes of HTLV-1 transmission are mother to child, sexual transmission, and transmission with contaminated blood products. Twenty years ago, de Thé and Bomford estimated the total number of HTLV-1 carriers to be 10-20 millions people. At that time, large regions had not been investigated, few population-based studies were available and the assays used for HTLV-1 serology were not enough specific. Despite the fact that there is still a lot of data lacking in large areas of the world and that most of the HTLV-1 studies concern only blood donors, pregnant women, or different selected patients or high-risk groups, we shall try based on the most recent data, to revisit the world distribution and the estimates of the number of HTLV-1 infected persons. Our best estimates range from 5-10 millions HTLV-1 infected individuals. However, these results were based on only approximately 1.5 billion of individuals originating from known HTLV-1 endemic areas with reliable available epidemiological data. Correct estimates in other highly populated regions, such as China, India, the Maghreb, and East Africa, is currently not possible, thus, the current number of HTLV-1 carriers is very probably much higher.

Adult T-cell leukemia: a review of epidemiological evidence

Adult T-cell leukemia (ATL) is an aggressive T-cell malignancy caused by human T-cell leukemia virus type I (HTLV-1) infection and often occurs in HTLV-1-endemic areas, such as southwestern Japan, the Caribbean islands, Central and South America, Intertropical Africa, and Middle East. To date, many epidemiological studies have been conducted to investigate the incidence of ATL among general population or HTLV-1 carriers and to identify a variety of laboratory, molecular, and host-specific markers to be possible predictive factors for developing ATL because HTLV-1 infection alone is not sufficient to develop ATL. This literature review focuses on the epidemiology of ATL and the risk factors for the development of ATL from HTLV-1 carriers, while keeping information on the epidemiology of HTLV-1 to a minimum. The main lines of epidemiological evidence are: (1) ATL occurs mostly in adults, at least 20-30 years after the HTLV-1 infection, (2) age at onset differs across geographic areas: the average age in the Central and South America (around 40 years old) is younger than that in Japan (around 60 years old), (3) ATL occurs in those infected in childhood, but seldom occurs in those infected in adulthood, (4) male carriers have about a three- to fivefold higher risk of developing ATL than female, (5) the estimated lifetime risk of developing ATL in HTLV-1 carriers is 6-7% for men and 2-3% for women in Japan, (6) a low anti-Tax reactivity, a high soluble interleukin-2 receptor level, a high anti-HTLV-1 titer, and high levels of circulating abnormal lymphocytes and white blood cell count are accepted risk factors for the development of ATL, and (7) a higher proviral load (more than 4 copies/100 peripheral blood mononuclear cells) is an independent risk factor for progression of ATL. Nevertheless, the current epidemiological evidence is insufficient to fully understand the oncogenesis of ATL. Further well-designed epidemiological studies are needed.

Human T-lymphotropic virus type 1 prevalence in northeastern Iran, Sabzevar: an epidemiologic-based study and phylogenetic analysis

Human T-lymphotropic virus type 1 (HTLV-I) is an important global health problem in the world mainly in the endemic areas of HTLV-I infection. It was previously reported that Mashhad, in northeastern Iran, is a new endemic region of HTLV-I. The aim of this study was to examine the prevalence and phylogenetic analysis of HTLV-I in Sabzevar, located in the southeast of Mashhad. In this cross-sectional study 1445 individuals were selected by multistage cluster sampling. Serum samples were screened for anti-HTLV-I antibody using enzyme-linked immunosorbent assay (ELISA); all of the ELISA-positive samples were confirmed by polymerase chain reaction (PCR). Long terminal repeat (LTR) sequencing was carried out to determine the type of HTLV-I in Sabzevar. In the primary screening by ELISA, 26/1445 (1.8%) of those sampled were reactive for HTLV-I antibody. Twenty-four out of 26 samples were confirmed HTLV-I infection by PCR (24/1445). The overall prevalence of HTLV-I infection in Sabzevar is 1.66%. The prevalence of the virus infection in men and women was 2.42% (11/455) and 1.31% (13/989), respectively. Seroprevalence was associated with age, increasing significantly among those older than 30 years (p=0.015), and a history of surgery (p=0.002), imprisonment (p=0.018), and hospitalization (p=0.005). Three out of 24 positive HTLV-I samples were selected for sequencing and phylogenetic analysis of LTR. The results showed that HTLV-I in Sabzevar belonged to the cosmopolitan subtype. The present study showed Sabzevar is a new endemic area for HTLV-I infection. Our study emphasizes that systemic HTLV-I screening of blood donors in Sabzevar and other cities in Khorasan province is important and should be taken into account.

Guillain-Barré-like Syndrome, as a Rare Presentation of Adult T-cell Leukemia-Lymphoma (ATLL): A Case Report

We report a 21-year-old woman who was admitted because of unilateral facial paresis and then developed progressive ascending flaccid tetraparesis with generalized areflexia. Electrodiagnostic studies revealed acute motor axonal polyradiculoneuropathy (AMAN type of Guillain-Barré Syndrome). Further evaluations revealed severe leukocytosis, increased erythrocyte sedimentation rate (ESR), increased protein content and presence of a few lymphocytes in cerebrospinal fluid (CSF), and then presence of human T-cell lymphotropic virus type 1 (HTLV-I) in serum and CSF. Finally, biopsy of the enlarged lymph nodes resulted in the diagnosis of Adult T-cell Leukemia-Lymphoma. The HTLV-1 has been endemic to certain parts of Iran like Khorasan province in the northeast since 1985 with 2.3% prevalence rate of infection. Thus, some rare neurologic complications occasionally occur in this area as a result of being infected with HTLV-1.

Design and development of a quantitative real time PCR assay for monitoring of HTLV-1 provirus in whole blood

BACKGROUND

Proviral load quantification of human T-lymphotropic virus type 1 (HTLV-1) is an essential marker for disease progression. Therefore, accurate and precise quantification of the virus is important. However, many articles published about detection and quantification of HTLV-1 virus neither reported any databank for the pre-validation of their primer and probe sequences nor stressed on its importance. Consequently, this failure may cause proviral load measurement variations of different HTLV-1 strains.

OBJECTIVE

The aim of this study was to develop a TaqMan assay for HTLV-1 proviral load quantification which is based on a conserved region of tax gene with minimal sequence variability.

STUDY DESIGN

For the purpose of finding the most conserved region of tax gene, all the HTLV-1 Gene Bank records including tax gene sequence (524 records by December 2009) were aligned in order to design on the most conserved region of this gene. The specificity, sensitivity, inter and intra assay and the dynamic range of the assay were experimentally determined by their respective methodology.

RESULT

The assay has a dynamic range of 10-10(7) HTLV-1 plasmid DNA/rxn (reaction) and the limit of detection (LOD) less than 10 copies/rxn. The assay gave coefficient of variation (CV) for the Ct values of less than 1% and 4.8% for intra and inter assay, respectively. Clinical sensitivity and specificity were determined to be 97.8% and 100%, respectively.

CONCLUSION

This TaqMan assay is able to reliably quantify proviral load due to the fact that it has been designed on a conserved region of HTLV-1 tax gene with minimal sequence variability.

High prevalence of HTLV-I infection in Mashhad, Northeast Iran: a population-based seroepidemiology survey

BACKGROUND

Mashhad, in the northeast of Iran has been suggested as an endemic area for human T cell lymphotropic virus type I (HTLV-I) infection since 1996.

OBJECTIVES

We performed a community-based seroepidemiology study to examine the prevalence and risk factors for HTLV-I infection in the city of Mashhad.

STUDY DESIGN

Between May and September 2009, overall 1678 subjects from all the 12 geographical area of Mashhad were selected randomly by multistage cluster sampling for HTLV antibody. The study population included 763 males and 915 females, with the mean age of 29.1 ± 18.5 years. 1654 serum samples were assessed for HTLV antibody using ELISA and reactive samples were confirmed by Western blot and PCR.

RESULTS

The overall prevalence of HTLV-I infection in whole population was 2.12% (95% CI, 1.48-2.93) with no significant difference between males and females (p = 0.093) and the prevalence of HTLV-II seropositivity was 0.12% (95% CI, 0.02-0.44). The HTLV-I Infection was associated with age (p<0.001), marital status (p<0.001), education (p = 0.047), and history of blood transfusion (p = 0.009), surgery (p<0.001), traditional cupping (p = 0.002), and hospitalization (p = 0.004). In logistic regression analysis, age was the only variable that had a significant relation with the infection (p = 0.006, OR = 4.33).

CONCLUSIONS

Our results demonstrated that Mashhad still remains an endemic area for HTLV-I infection despite routine blood screening. Thus, further strategies are needed for prevention of the virus transmission in whole population.

Epidemiology of HTLV-1 in Neyshabour, Northeast of Iran

BACKGROUND

HTLV-1 infection is endemic in Mashhad, Northeast of Iran. This study was designed to assess the epidemiology of HTLV-1 and potential risk factors in Neyshabour, Northeastern Iran.

METHODS

All those who referred to Iranian Academic Center for Education, Culture and Research (ACECR)- Mashhad Laboratory in Neyshabour for evaluation of HTLV-I by ELISA, were tested using WB if the ELISA result was positive. A questionnaire about risk factors of infection was completed for all cases.

RESULTS

HTLV-1 infection was positive in 7.2% (35/483) of the participants according to the results of enzymelinked immunosorbent assay (ELISA) and western blot (WB) tests. Infection was significantly associated with age, family size, income and blood transfusion. However, gender, education, birthplace, race, marital status, and history of surgery, dentistry, traditional cupping, and hospitalization showed no significant relation.

CONCLUSION

It seems that HTLV-I infection is highly endemic in Neyshabour and it is seems that more effective treatment strategies are needed.

Molecular analysis of human T cell lymphotropic virus type 1 and 2 (HTLV-1/2) seroindeterminate blood donors from Northeast Iran: evidence of proviral tax, env, and gag sequences

Human T cell lymphotropic virus type 1 and 2 (HTLV-1/2) Western blot indeterminate results are a problem for blood banks in endemic areas. To determine the prevalence of HTLV-1/2 infection among indeterminate donors, we analyzed 130 cases from Mashhad, an HTLV-1/2 endemic area in Northeast Iran. The most frequent Western blot bands were GD21 alone (37.2%) followed by rgp46-2 alone (32.1%). We further tested 40 available DNA samples of these cases by PCR for viral sequences, tax, gag, and pol, and found five cases (12.5%) to be positive for two or three HTLV-1 genes. There were no significant age, sex, and blood group differences between PCR-positive and PCR-negative cases. Among PCR-positive individuals, the most prevalent Western blot bands were variable combinations of rgp46-1, GD21, and gp21. The mean of the optical density (OD) of the enzyme-linked immunosorbent assay (ELISA) test was significantly higher in PCR-positive individuals. The frequency of the rgp46-1 band was also significantly higher in PCR-positive cases compared to PCR-negative ones. In conclusion, the majority of HTLV-indeterminate donors lack the HTLV provirus and therefore are not considered infected. However, in some cases with higher ODs in the ELISA test and seroreactivity to env proteins, rgp46-1 and GD21 in particular may be indicative of infection and need further evaluation by molecular methods.

Adult T-cell leukemia/lymphoma in the Middle East: first report of two cases from Lebanon

BACKGROUND

Adult T-cell leukemia/lymphoma (ATL) is an aggressive lymphoproliferative disorder caused by human T-cell leukemia virus type I (HTLV-I). HTLV-I is endemic in southern Japan, the Caribbean, Central and South America, certain areas of Africa, and the southeastern United States. In the Middle East, North East Iran, particularly the region of Mashhad, has been recognized as an endemic region.

CASE REPORTS

In this report, the first two cases of ATL diagnosed in Lebanon are described. The first patient of Lebanese origin presented with acute ATL. The second patient of Romanian origin developed acute ATL in early relapse after autologous transplantation for ATL. Both patients had lymphocytosis, severe hypercalcemia, and CD25+ T-cell immunophenotype on peripheral blood. In both patients, HTLV-I serology was positive by enzyme-linked immunosorbent assay and confirmed by Western blot and HTLV-I oncoprotein Tax expression was documented in the leukemic cells. Upon screening, seven direct family members of the first patient were HTLV-I positive; four of them were regular blood donors.

CONCLUSIONS

Screening blood donors for HTLV-I seropositivity is not currently performed in Lebanon. A large screening study in Lebanon is needed to confirm whether South Lebanon is a new endemic region for HTLV-I infection and to recommend mandatory screening of blood donors for HTLV-I infection.

Association between ABO and Rhesus blood group systems among confirmed human T lymphotropic virus type 1-infected patients in Northeast Iran

The distribution of ABO and Rhesus blood group types was investigated in 984 randomly selected human T lymphotropic virus-1(HTLV-1)-infected blood donors from April 2004 to March 2007. A total of 1081 healthy controls admitted for blood donation in this period were enrolled in this study. Infected and control individuals were from the same region and their ABO/Rhesus blood group types were determined by the standard tube test technique. All blood samples were screened for HTLV-1 using an enzyme-linked immunosorbent assay (ELISA) and positive samples were confirmed by Western blot (WB). The unmatched analyses showed significant differences in frequency of the A+ blood group between healthy controls and HTLV-1-infected individuals (OR = 0.8, 95% CI = 0.66-0.97) and also a significant association was observed between these two groups(OR = 1.42, 95% CI = 1.1-1.99, p = 0.021). No significant difference in blood group (A-, B+, B-, O+, O-, and AB-) was observed between cases and controls. It is the first report of an association between HTLV-1-infected patients and ABO/Rh blood groups in our literature review. Our results might suggest that the A+ blood group decrease the risk of HTLV-1 infection in healthy controls, while the AB+ blood group is more frequent in HTLV-1 carriers and increases the risk of HTLV-1 infection.

Increased microvessel density in involved organs from patients with HTLV-I associated adult T cell leukemia lymphoma

Adult T-cell leukemia-lymphoma (ATLL) is a rapidly progressive lymphoproliferative disorder secondary to infection with the human T cell lymphotropic virus type I (HTLV-I). The role of angiogenesis in the development and prognosis of many hematologic malignancies is established. We have previously shown that ATLL derived cells secrete high levels of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (b-FGF), induce endothelial tube formation in vitro and establish functional gap junction-mediated communication with endothelial cells. We also demonstrated that plasma from ATLL and tropical spastic paraparesis/HTLV-I associated myelopathy patients exhibit very high levels of VEGF and b-FGF. Recently, we showed that treatment with the combination of zidovudine and interferon alpha reduced both HTLV-I proviral load and importantly VEGF plasma levels suggesting a potential anti-angiogenic effect of this therapy. In this report, we evaluated microvessel density (MVD) in involved organs from 20 patients with ATLL, as compared to normal organs from matched controls. We show evidence of significantly increased MVD in all tested involved organs from ATLL patients, suggesting that angiogenesis plays an important role in the development or organ invasion of ATLL, and could represent a potentially interesting target for anti-angiogenic therapy of ATLL.

Zidovudine and interferon-alpha treatment induces a high response rate and reduces HTLV-1 proviral load and VEGF plasma levels in patients with adult T-cell leukemia from North East Iran

Human T-cell lymphotropic virus type I (HTLV-I) associated adult T-cell leukemia/lymphoma (ATLL) is endemic in southern Japan, the Caribbean, intertropical Africa, and Brazil. Recently north east Iran, particularly the region of Mashhad, has been recognized as a new endemic region. ATLL is an aggressive T-cell lymphoproliferative disorder. Patients with ATLL have high plasma levels of VEGF that induce angiogenesis. Prognosis of ATLL remains poor because of immunosuppression and intrinsic resistance to chemotherapy. Important advances in the treatment of ATLL were reported with the combination of zidovudine (AZT) and interferon-alpha. We investigated the effect of AZT/IFN treatment on vascular endothelium growth factor (VEGF) plasma levels and HTLV-I proviral load in ATLL patients from the region of Mashhad. We confirmed that AZT/IFN treatment induces a high response rate and prolonged survival with minimal side effects. We also confirmed that VEGF plasma levels and HTLV-I proviral load are higher in ATLL patients than in asymptomatic carriers. We finally showed that AZT/IFN treatment reduced both HTLV-I proviral load and importantly VEGF plasma levels, suggesting a potential antiangiogenic effect of this therapy. These results provide further evidence for the efficacy and the mechanism of action of AZT/IFN therapy for ATLL in a developing country.

Differences in viral and host genetic risk factors for development of human T-cell lymphotropic virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis between Iranian and Japanese HTLV-1-infected individuals

Human T-cell lymphotropic virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a neurological disease observed only in 1–2 % of infected individuals. HTLV-1 provirus load, certain HLA alleles and HTLV-1 tax subgroups are reported to be associated with different levels of risk for HAM/TSP in Kagoshima, Japan. Here, it was determined whether these risk factors were also valid for HTLV-1-infected individuals in Mashhad in northeastern Iran, another region of endemic HTLV-1 infection. In Iranian HTLV-1-infected individuals (n=132, 58 HAM/TSP patients and 74 seropositive asymptomatic carriers), although HLA-DRB1*0101 was associated with disease susceptibility in the absence of HLA-A*02 (P=0·038; odds ratio=2·71) as observed in Kagoshima, HLA-A*02 and HLA-Cw*08 had no effect on either the risk of developing HAM/TSP or HTLV-1 provirus load. All Iranian subjects possessed tax subgroup A sequences, and the protective effects of HLA-A*02 were observed only in Kagoshima subjects with tax subgroup B but not in those with tax subgroup A. Both the prevalence of HTLV-1 subgroups and the host genetic background may explain the different risks levels for HAM/TSP development in these two populations.

HTLV-1 Associated Motor Neuron Disease Mimicking "Man-in-the-Barrel" Syndrome

The "man-in-the-barrel" syndrome is a descriptive term that was used in the past for patients with complete flaccid paralysis of the upper extremities caused by symmetric "watershed" brain infarction after cardiovascular arrest or cardiac surgery. However, it is now evident that this syndrome can occur in acute and chronic diseases of the upper and lower motor neuron. We describe a 48-year-old woman with rapid and severe progressive weakness and wasting of both upper extremities mimicking the "man-in-the-barrel" syndrome. The neurologic and electrophysiological findings were compatible with anterior horn cell disease affecting the cervical spinal cord segments. There were only minimal signs suggesting the presence of myelopathy. After the initial rapid onset, progression during the 7 years of follow up was minimal. An extensive etiologic workup disclosed infection with HTLV-1.

Association of a novel single nucleotide polymorphism in the human perforin gene with the outcome of HTLV-I infection in patients from Northeast Iran (Mash-had)

Human T lymphotropic virus I (HTLV-I)-specific cytotoxic T lymphocytes (CTL) recognize the products of the HTLV-I Tax, in the context of HLA-A2 and kill their target through a perforin-dependent mechanism. The efficiency of the CTL response may lead HTLV-I-infected individuals to remain carriers or to the development of HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Perforin is a cytolytic molecule that contributes to CTL-mediated killing of virus-infected cells. Thus polymorphism in the perforin gene may determine the efficiency of the CTL response in HTLV-I-infected individuals. In this study, we performed single-stranded conformational polymorphism (SSCP) and DNA sequencing to analyze the promoter, 5' UTR and first intron of the perforin gene to identify novel polymorphisms. We detected a novel polymorphism in the first intron at position +418*C/T, relative to the transcription start site. Genotyping of patients with HAM/TSP, HTLV-I carriers, and healthy controls revealed that the frequency of the C allele was statistically significantly increased in HAM/TSP patients compared with healthy controls group (p = 0.005). The frequency of the C allele was higher, but not significantly so, in the HAM/TSP group compared with HTLV-I carriers (p = 0.09), whereas there was no difference between HTLV-I carriers and healthy controls. Our results suggest that the perforin +418*C/T polymorphism is associated with the outcome of HTLV-I infection.

Prevalence of human T-lymphotropic virus type 1 among blood donors from Mashhad, Iran

The city of Mashhad is the capital of Khorasan, the northeastern province of Iran, which has been recognized as an area where human T-lymphotropic virus type 1 (HTLV-1) infection is endemic. All serum samples from blood donors are routinely screened for HTLV-1 by using enzyme-linked immunosorbent assay (ELISA). In the present study, 28,926 donors (81.86% male and 18.14% female) with a mean age of 32 years (range, 18 to 65 years) were screened in a 6 months period (July to December 1999). Of these donors in the primary screening, 228 (0.78%) tested positive by ELISA. The positive samples were confirmed by Western blot (WB) analysis. The WB results indicated that, of 228 positive ELISA specimens, 91.2% (208 specimens) were HTLV-1, 4.82% (11 specimens) were HTLV, 3.5% (8 specimens) were indeterminate, and 0.44% (1 specimen) was not confirmed. HTLV refers to samples in which the complete viral antigen banding patterns on WB strips were not present. In order to further evaluate the detection methodologies used, the HTLV-1-seropositive samples, the indeterminant samples, and/or HTLV samples were examined and confirmed by PCR. The HTLV samples were determined to be HTLV-1, the remaining samples were indeterminant, and the negative sample could not be confirmed for HTLV-1 by PCR. The prevalence of HTLV-1 infection in our study was 0.77% among blood bank donors, which reconfirms the city of Mashhad as an area where the virus is endemic compared to other regions in the world. The incidence was correlated with increasing age, and it was higher in females than in males.

Os vírus linfotrópicos de células T humanos (HTLV) na última década (1990-2000): aspectos epidemiológicos

Vinte anos após o isolamento do vírus linfotrópico humano tipo I, muitos aspectos epidemiológicos, patogênicos e filogenéticos já estão esclarecidos. Sabe-se que em regiões endêmicas a prevalência aumenta com a idade e é maior no sexo feminino. Três patologias estão claramente relacionadas a ele: paraparesia espástica tropical / mielopatia associada ao HTLV, leucemia de células T do adulto e uveíte. Os modos de infecção, semelhantes aos dos outros retrovírus, são: transfusão de sangue, relações sexuais não protegidas, transplacentária e durante o aleitamento materno. A história natural das doenças relacionadas ao HTLV-I ainda não está bem estabelecida. O risco de portadores da infecção desenvolverem patologias depende de mais estudos de incidência para serem corretamente estimados. Menos se conhece sobre o HTLV-II. A despeito do alto grau de homologia entre os dois tipos, os vírus interagem de forma bem diversa com os infectados, não havendo uma associação clara de doença com o HTLV-II. Relatos recentes têm apontado sua participação em casos de mielopatia crônica semelhante à TSP/HAM. As implicações incertas do prognóstico para pessoas infectadas pelo vírus linfotrópico humano (HTLV-I/II) e suas formas de transmissão constituem um problema de saúde pública, principalmente em áreas consideradas endêmicas para esse vírus.

Ethnic cluster of HTLV-I infection in Israel among the Mashhadi Jewish population

A high prevalence of human T-lymphotropic virus type I (HTLV-I) infection among Israeli Jews was previously reported. In the present study, screening for HTLV-I of Israeli Jews was expanded to 10 ethnic groups. HTLV-I antibodies were tested by the particle agglutination assay, ELISA, and by Western blot as a confirmatory method. The HTLV-I proviral genome was tested by nested PCR with tax primers (SK43/SK44 and Tr101/Tr102). The PCR tests were carried out in all seropositive subjects and the seronegative family members of the seropositives subjects in the Iranian population. Sixty-eight of the 1,679 subjects (4.1%) were found to be seropositive. The Jews originating from Mashhad had the highest infection rate of 60/306 (20%). Of the 479 Iranian non-Mashhadi Jews, 6 (1.3%) were seropositive. Of the 894 non-Iranian Israelis, only 2 (0.2%) were seropositive. HTLV-I proviral DNA was found in the peripheral blood lymphocytes of 66 out of 68 seropositive subjects and 6 out of 75 seronegative subjects. Sixty out of 123 (49%) Mashhadi Jews and 8 out of 14 (57%) non-Mashhadi Iranian Jews were PCR-positive. Three out of three seropositive non-Iranian Israelis were PCR positive. One non-Iranian Israeli (who originated from Ukraine) without family connections to the Iranian Jews was also PCR-positive. One hundred eighteen saliva samples (84 from subjects of Mashhadi origin, 31 from Iranian origin, and 4 of other origins) were also screened. Antibodies for HTLV-I were found in 23 out of 46 saliva samples from the individuals with particle agglutination (PA) and/or PCR-positive findings in blood. Twenty out of 23 PA-positive saliva samples also contained the proviral DNA. It is concluded that HTLV-I infection in Israel is mainly limited to Jews originating from Iran (most of them from Mashhad) and their family members.

Common origin of human T-lymphotropic virus type-I from Iran, Kuwait, Israel, and La Réunion Island

We found previously that Kuwaiti HTLV-I isolates had two nucleotide substitutions in the most frequently sequenced regions of HTLV-I genome, namely: T-->C 4783 in the pol and T-->C 6569 the env genes. These substitutions were observed rarely in other HTLV-I isolates and seemed to be good markers of the HTLV-I lineage, the "epicentre" of which was located in Mashhad, Iran. To test this hypothesis we sequenced the fragments of HTLV-I genome including sites 4783 and 6569 from seven isolates obtained from the Iranians either living in (five isolates) or originating from (two isolates) Mashhad. RFLP-based tests were also designed and used for typing of the substitutions. All seven isolates were positive for T-->C 4783 and six, from which env fragment was amplifiable, were also positive for T-->C 6569. It is highly probable that all the isolates from Mashhadi Jews belong to the same HTLV-I lineage, although they were not typed yet for the presence of T-->C 6569 substitution. Only 2 "non-Middle Eastern" HTLV-1, both from La Réunion Island were positive for both of the substitutions. Another possible member of Mashhadi lineage of HTLV-I is one isolate from southern India and two isolates from the American Indians, British Columbia, Canada. The determination of the T-->C 4783 and T-->C 6569 markers in HTLV-I isolates of different geographical/ethnic origin may be useful for the reconstruction of the routes of HTLV-I spread from the Middle East and/or Indian subcontinent to other regions of the world and, possibly, for gaining insights into the origin of HTLV-I in Asia.