Skeletal muscle involvement in tropical spastic paraparesis/HTLV-1-associated myelopathy.
The frequency of muscle involvement in TSP/HAM is not known, nor is the precise role that HTLV-1 and the diverse cytokines play in the genesis of HTLV-1-associated diseases. In order to better define the frequency and characteristics of the skeletal muscle involvement in TSP/HAM, we studied 11 affected patients. EMG was performed in 9 patients and muscle biopsy was performed in all 11. Muscle tissue was analyzed using: reverse transcriptase PCR for interleukin-1 in 8; PCR for HTLV-1 proviral DNA in 5; and electron microscopy for viral particles in 3. We found pathologic alterations in all 11 patients. Four patients (36%) had a neurogenic process, while a primary muscle involvement was observed in the rest (64%). Four patients (36%) had polymyositis, and 3 (27%) had a noninflammatory myopathy. Muscle weakness in the upper limbs was significantly associated with inflammation in the muscle biopsy. EMG was abnormal in only 2 of 9 patients. Reverse transcriptase PCR did not demonstrate message for interleukin-1 in any sample examined. PCR did identify HTLV-1 proviral DNA in the muscle of 3 patients. Retroviral-like particles were found, by EM, in only one biopsy. HTLV-1 may play an important role in the pathogenesis of the frequent myopathies associated with HAM/TSP.
Gabbai
A A
AA
Department of Neurology, Escola Paulista de Medicina, Brazil.
Wiley
C A
CA
Oliveira
A S
AS
Smith
R
R
Schmidt
B
B
Nóbrega
J A
JA
Bordin
J O
JO
Román
G C
GC
D000328:Adult; D001483:Base Sequence; D017931:DNA Primers; D004279:DNA, Viral / Q000235:genetics; D005260:Female; D015368:Human T-lymphotropic virus 1 / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009132:Muscles / Q000473:pathology*; D015493:Paraparesis, Tropical Spastic / Q000235:genetics / Q000473:pathology*; D011533:Proviruses / Q000235:genetics
D017931:DNA Primers; D004279:DNA, Viral