Human T cell leukemia virus type I-infected patients with Hashimoto's thyroiditis and Graves' disease.
BACKGROUND
Autoimmune thyroid diseases have been reported to be associated with human T cell leukemia virus type I (HTLV-I) infection. HTLV-I proviral load is related to the development of HTLV-I-associated myelopathy/tropical spastic paraparesis and has also been shown to be elevated in the peripheral blood of HTLV-I-infected patients with uveitis, arthritis, and connective tissue disease.


OBJECTIVE
The objective of the study was to evaluate the proviral load in HTLV-I-infected patients with Hashimoto's thyroiditis (HT) or Graves' disease (GD) and ascertain the ability of HTLV-I to infect thyroid cells.


METHODS
A quantitative real-time PCR assay was developed to measure the proviral load of HTLV-I in peripheral blood mononuclear cells from 26 HTLV-I-infected patients with HT, eight HTLV-I-infected patients with GD, or 38 asymptomatic HTLV-I carriers. Rat FRTL-5 thyroid cells were cocultured with HTLV-I-infected T cell line MT-2 or uninfected T cell line CCRF-CEM. After coculture with T cell lines, changes in Tax and cytokine mRNA expression were studied by RT-PCR.


RESULTS
HTLV-I proviral load was significantly higher in the peripheral blood of patients with HT and GD than asymptomatic HTLV-I carriers. In the peripheral blood from HTLV-I-infected patients with HT, HTLV-I proviral load did not correlate with the thyroid peroxidase antibody or thyroglobulin antibody titer. After coculture with MT-2 cells, FRTL-5 cells expressed HTLV-I-specific Tax mRNA. These cocultured FRTL-5 cells with MT-2 cells expressed IL-6 mRNA and proliferated more actively than those cocultured with CCRF-CEM cells.


CONCLUSIONS
Our findings suggest the role of the retrovirus in the development of autoimmune thyroid diseases in HTLV-I-infected patients.
Matsuda
Takehiro
T
Division of Molecular Virology and Oncology, Graduate School of Medicine, University of the Ryukyus, 207 Uehara, Nishihara, Okinawa, 903-0215, Japan.
Tomita
Mariko
M
Uchihara
Jun-Nosuke
JN
Okudaira
Taeko
T
Ohshiro
Kazuiku
K
Tomoyose
Takeaki
T
Ikema
Tomoki
T
Masuda
Masato
M
Saito
Mineki
M
Osame
Mitsuhiro
M
Takasu
Nobuyuki
N
Ohta
Takao
T
Mori
Naoki
N
D000328:Adult; D000368:Aged; D000818:Animals; D018791:CD4 Lymphocyte Count; D002460:Cell Line; D049109:Cell Proliferation; D018920:Coculture Techniques; D016207:Cytokines / Q000096:biosynthesis / Q000235:genetics; D004279:DNA, Viral / Q000096:biosynthesis / Q000235:genetics; D005260:Female; D006111:Graves Disease / Q000150:complications*; D015490:HTLV-I Infections / Q000150:complications* / Q000821:virology; D006801:Humans; D015458:Leukemia, T-Cell / Q000150:complications; D015459:Leukemia-Lymphoma, Adult T-Cell / Q000821:virology; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D012334:RNA, Neoplasm / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013967:Thyroiditis, Autoimmune / Q000150:complications*; D019562:Viral Load
D016207:Cytokines; D004279:DNA, Viral; D012333:RNA, Messenger; D012334:RNA, Neoplasm