Human T-cell lymphotropic virus type 1 provirus and phylogenetic analysis in patients with mycosis fungoides and their family relatives.
BACKGROUND
Mycosis fungoides (MF) is a cutaneous T-cell lymphoma of unknown aetiology. A pathogenic role of human T-cell lymphotropic virus type 1 (HTLV-1) has been suggested but remains controversial. To determine whether MF is linked to HTLV-1.


METHODS
Blood samples were collected from 60 patients, 15 family relatives of patients with MF (MFRs), 20 healthy controls and 10 patients with HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The presence of HTLV-1 antibodies in serum was tested by the Western blot rp21e-enhanced test. DNA was extracted from the blood with the Qiagen blood kit. We used 500 ng of DNA either in conventional HTLV-1-specific polymerase chain reaction (PCR) or in real-time PCR using primers sk43 and sk44 together with a tax-specific fluorescent probe.


RESULTS
In Western blot, antibodies against three to four HTLV-1 antigens were detected in 52% of patients with MF. All of the patients with HAM/TSP were positive, while only 7% of the MFRs and none of the 20 healthy controls reacted with HTLV-1 antigens in Western blot. One of 60 patients with MF and one of 15 MFRs were positive in HTLV-1 PCR. These two PCR-positive samples which were quantified in real-time PCR showed that fewer than five in 10(6) cells were HTLV-1 infected. We succeeded in amplifying and sequencing the 5' end of the provirus from the blood of the PCR-positive MFR by seminested PCR. A positive result was also obtained in this test. Phylogenetic tree analyses revealed a high homology of this sequence with other HTLV-1 sequences from the Middle East. The above PCR-positive MFR was the brother of a PCR-negative patient with MF.


CONCLUSIONS
These findings demonstrate that HTLV-1 is probably not the aetiological agent of MF. However, it may play a role in immunosuppression and in the spreading of the disease.
Shohat
M
M
Department of Dermatology, Rabin Medical Center, Beilinson Campus, Petah Tikva, Israel.
Shohat
B
B
Mimouni
D
D
Pauli
G
G
Ellerbrok
H
H
David
M
M
Hodak
E
E
D000328:Adult; D000368:Aged; D004279:DNA, Viral / Q000097:blood; D005260:Female; D015481:HTLV-I Antibodies / Q000097:blood; D015368:Human T-lymphotropic virus 1 / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009182:Mycosis Fungoides / Q000821:virology*; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000379:methods; D011533:Proviruses / Q000235:genetics / Q000302:isolation & purification*; D012878:Skin Neoplasms / Q000235:genetics / Q000821:virology*
D004279:DNA, Viral; D015481:HTLV-I Antibodies