Spastic paraparesis associated with human T-lymphotropic virus type I: a clinical, serological, and genomic study in Iranian-born Mashhadi Jews

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.

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.

HTLV-1 infection and the viral etiology of multiple sclerosis

The HTLV-1 virus produces a progressive inflammatory, and then degenerative, myelopathy which evolves progressively from onset. HTLV-1 in endemic in populations which are recognized as having low risk of multiple sclerosis . Multiple sclerosis generally evolves as a relapsing-remitting disease and affects predominantly Caucasians. In Caucasians, HAM/TSP can be marked by fluctuations as well as relapses. In Asians MS affects preferentially the spinal cord. The author hypothesizes that population selection through environmental factors has pushed the immune response of Caucasians towards generating relapsing-remitting disease and that of Primordial populations towards progressive disease. HTLV-1 endemicity being the marker of Primordial populations and its absence that of Caucasians.

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.

Human T-lymphotropic virus type 1 infection

Human T-cell lymphotropic virus type-1 (HTLV-1) is aetiologically associated with adult T-cell leukaemia/lymphoma (ATL). HTLV-1 infection can also lead to various non-malignant diseases, for example, HTLV-1 associated myelopathy/tropical spastic paraparesis and HTLV-1 uveitis. HTLV-1 is endemic in southern Japan and the Caribbean. HTLV-1 infection is mainly transmitted by either breast-feeding, sexual intercourse or blood transfusions. Primary prevention of HTLV-1 in endemic areas by screening of blood and by refraining from breast-feeding have been successful. The incidence of ATL is rather low among HTLV-1 carriers (<5%). The precise mechanism of development of ATL remains unknown. It is a multiple-step process which does not require viral expression in the later stages of leukaemogenesis. Many samples have mutations of the tumour suppressor genes, p53 and/or p16(INK4A). Four subtypes of ATL have been identified, each having distinctive clinical features. Monoclonal integration of HTLV-1 proviral DNA into tumour cells is found in each of the subtypes. At present, no effective therapy for ATL exists.

Evidence for the cofactor role of human T-cell lymphotropic virus type 1 in mycosis fungoides and Sézary syndrome

The aetiology of mycosis fungoides (MF) and Sézary syndrome (SS) is unknown. A pathogenic role for the human T-cell lymphotropic virus type 1 (HTLV-1) has been suggested but remains controversial. We used an animal model to test the possibility that peripheral blood mononuclear cells (PBMC) obtained from MF patients harbour the HTLV-1 virus which may be infective. The polymerase chain reaction (PCR) was used to detect HTLV-1 proviral DNA sequences in PBMC of 27 MF patients and one SS patient of non-Iranian origin. Positive results were found in six of the patients. Twelve of the 28 patients tested by Western blot showed HTLV-1 antibodies. Twenty-eight immunosuppressed inbred Fisher F344 rats were inoculated intravenously with cultures of PBMC obtained from the 28 patients. Eight of these 28 rats showed antibodies to HTLV-1 while the proviral genome was demonstrated in the blood of only two of the rats. PBMC from two MF patients, in spite of showing negative results for the proviral genome by PCR, still induced HTLV-1 antibody formation in the F344 rat model. None of 10 control rats inoculated with normal donor PBMC showed antibodies to HTLV-1, nor the proviral genome. The present study suggests that HTLV-1 plays a cofactor role in MF/SS patients.

Transmission of HTLV-I to rats via peripheral blood mononuclear cells and serum from a patient with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) with amyotrophic lateral sclerosis (ALS)-like features

We tested the possibility that lymphocytes and serum obtained directly from a patient with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) induce infection in rats. Inbred Fischer F344 immunosuppressed rats were inoculated intravenously with 10x10(6) peripheral blood mononuclear cells (PBMC; 3 rats) and serum (3 rats) obtained from a HAM/TSP patient, who was seropositive and polymerase chain reaction (PCR)-positive for the HTLV-I proviral genome. Antibodies to HTLV-I appeared in the rat sera 2 months later; rat peripheral blood lymphocytes, spleen, salivary gland, and spinal cord were found to contain the proviral genome. Control rats inoculated with normal donor PBMC and serum tested negative for the HTLV-I antibodies and for the HTLV-I proviral genome by PCR. The positive control F344 rats inoculated with 5x10(6) cells of a SLB-1 HTLV-I cell line were found to be infected after 2 months. This study demonstrates for the first time that HTLV-I can be transmitted not only by human cellular components but also by human cell-free sera in a rat model.

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.

Detection of HTLV type I provirus by in situ polymerase chain reaction in mouthwash mononuclear cells of HAM/TSP patients and HTLV type I carriers

Molecular studies have revealed the presence of HTLV-I provirus DNA in saliva of HTLV-I-infected subjects. However, cellular localization has not been determined. In the present study, we have used in situ PCR technique to study saliva-associated cells for localization of HTLV-I proviral DNA. We found that HTLV-I proviral DNA was present in the nuclei and cytoplasm of salivary lymphocytes in five (71%) of seven HTLV-I-seropositive subjects. The percentage of infected cells in positive mouthwash samples ranged from 0.5 to 2%. None of the HTLV-I-negative patients had HTLV-I provirus in saliva. The localization of HTLV-I provirus DNA suggests that salivary lymphocytes can serve as vector for HTLV-I infection through saliva.

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.

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

Several publications describe the presence of the human T cell lymphotropic virus type I (HTLV-I) in Jewish individuals born in Mash-had, Iran. We report here the results of HTLV-I serological and genetic studies in the non-Jewish population of Mash-had as well as a neighboring area: Gonbad-Kavous. Seven hundred and seven serum samples from Mash-had (694 healthy individuals and 13 patients with lymphoma) and 90 from Gonbad-Kavous were tested for HTLV antibodies by gelatin particle agglutination assay (PA) and confirmatory Western blots (WBs). Seropositive rates of 3.0% (21 of 694) in Mash-had, 0% (0 of 90) in Gonbad-Kavous, and 100% (13 of 13) in lymphoma cases were observed. HTLV-I DNA sequence were amplified by polymerase chain reaction directly from the fresh PBMCs of seropositive individuals. Phylogenetic analysis of the viral DNA sequence indicated that the HTLV-I present in Mash-had belong to the HTLV-I cosmopolitan clade. Altogether, these data indicate that Mash-had, located in northeastern Iran, is a newly recognized endemic center for HTLV-I.

Detection of proviral human T-cell lymphotrophic virus type I DNA in mouthwash samples of HAM/TSP patients and HTLV-I carriers

Human T-cell lymphotrophic virus type I (HTLV-I), is a member of the oncogenic retroviruses family endemic in several parts of the world and also recently identified in the Jewish Mashhadi population who immigrated from Iran to Israel. The virus is the causative agent of adult T-cell leukemia (ATL) and a chronic myelopathy known both as tropical spastic paraparesis (TSP) or HTLV-I associated myelopathy (HAM). The known modes of HTLV-I transmission are by sexual intercourse, from mother to child in breast milk, via blood transfusion, and by sharing of needles by parenteral drug users. In the present study we examined the presence of HTLV-I provirus genomic DNA by nested polymerase chain reaction (PCR) and by DNA hybridization in mouthwash samples obtained from 13 Mashhadi-born Iranian Jews with spastic paraparesis associated with HTLV-I, 4 Mashhadi-born Iranian Jews asymptomatic carriers for HTLV-I and 21 healthy controls. Proviral HTLV-I DNA was detected by mouthwash PCR in 12 of 17 HTLV-I infected subjects (71%) but in none of 21 controls. Proviral DNA was also detected in mouthwash samples using HTLV-I probe by dot blot hybridization assay. The presence of HTLV-I proviral DNA in whole saliva may suggest a possible transmission of the virus via saliva and explain the increased rate of infection in elderly Mashhadi-Jewish population.

Molecular characterization of human T-lymphotropic virus, type 1 (HTLV-1) found in Kuwait: close similarity with HTLV-1 isolates originating from Mashhad, Iran

Human T-lymphotropic virus, type 1 (HTLV-1) infection was detected in two unrelated Kuwaiti patients with tropical spastic paraparesis (HAM/TSP) and in the asymptomatic mother of one of them. The family roots of these patients were traced to the Najaf region of Iraq. The DNA sequence of three PCR-amplified fragments (env, 512 bp; pol, 140 bp; LTR, 704 bp) was determined for each of Kuwaiti HTLV-1 isolates (KUW-1,2,3). All three Kuwaiti HTLV-1 were identical in env and pol fragments and virtually identical in LTR. Two rare substitutions were found in the env and pol fragments. They were shared only with two isolates from Reunion Island (substitution in env), and two isolates from India and the Caribbean (substitution in pol). The sequences of env and pol fragments of the Middle Eastern HTLV-1 isolates were not available. However, the comparison of Kuwaiti isolates with representative Middle Eastern HTLV-1 was possible for the LTR fragment. The phylogenetic analysis of LTR sequences of KUW and 34 other HTLV-1 isolates has shown that Kuwaiti HTLV-1 belongs to a cosmopolitan "a" subtype of HTLV-1 and tends to cluster together with HTLV-1 originating from the Mashhad region of Iran. These results suggest that common origin of Mashhadi and Kuwaiti (Najafi) HTLV-1 and the possibility of another pocket of HTLV-1 infection in the Middle East, located in the Najaf region of Iraq.

Human T-cell lymphotropic virus type I in Iranian-born Mashhadi Jews: genetic and phylogenetic evidence for common source of infection

High prevalence of human T-cell lymphotropic virus type I (HTLV-I) infection and disease has been identified among Iranian-born Mashhadi Jews, an ethnically segregated, highly inbred population. To determine the origin and genetic diversity of HTLV-I in this group, 1,039 bp spanning selected regions of the HTLV-I gag, pol, env and pX genes were enzymatically amplified and sequenced directly from DNA of five Mashhadi Jews (three with spastic myelopathy and two asymptomatic carriers). Alignment and comparison of these sequences with cosmopolitan and Australo-Melanesian topotypes of HTLV-I indicated that the HTLV-I strains from Mashhadi Jews, which were > or = 99.9% identical among themselves, exhibited considerable sequence similarity (> or = 99%) to HTLV-I strains from southern India, suggesting a common source of infection. Phylogenetic analysis, using the maximum parsimony method, was consistent with a single-source introduction of HTLV-I into the Mashhadi Jewish community.

HTLV-I from Iranian Mashhadi Jews in Israel is phylogenetically related to that of Japan, India, and South America rather than to that of Africa and Melanesia

A new endemic focus of human T-lymphotropic virus type I (HTLV-I) was recently reported among Mashhadi Jews, a group of immigrants from northeastern Iran to Israel. We extracted DNAs from fresh peripheral blood mononuclear cells (PBMCs) and/or gargle mouthwash from 10 HTLV-I carriers, who consisted of members of one family, and HTLV-I-associated myelopathy (HAM) and adult T-cell leukemia (ATL) patients. Long terminal repeat (LTR) regions of proviral DNAs were sequenced and analyzed phylogenetically. In a phylogenetic tree, all the Mashhadi HTLV-I isolates belonged to subtype A, one of the three subtypes of the cosmopolitan type of HTLV-I, and made a tight cluster distinct from the other isolates of subtype A from Japan, India, the Caribbean Basin, and South America. Although a few nucleotide substitutions were observed among the clones sequenced, no characteristic sequence variation was found in different disease manifestations, even in one family or different sources of DNA preparation.