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

Abstract

The Mashhadi‐Jewish community originating in Iran is a closed and ethnically segregated population with a unique history and a high rate of intrafamilial marriage among its members. A high risk of infection by human T‐lymphotropic virus type I (HTLV‐I) and of adult T‐cell leukemia associated with such infection was found in this population. HTLV‐I is also associated with a syndrome of progressive spastic paraparesis. We therefore evaluated the occurrence of HTLV‐I infection and spastic paraparesis in Mashhadi‐born Iranian Jews who immigrated to Israel. We examined 83 Mashhadi‐born subjects (52 women, 31 men; mean age, 61 ± 15.5 years) and 73 age‐matched non‐Mashhadi Iranian‐born Jews. Blood samples were tested for HTLV‐I antibodies by particle agglutination test. The polymerase chain reaction (PCR) was used to detect HTLV‐I proviral DNA sequences from peripheral blood mononuclear cells. Fifteen Mashhadi‐born Jews (18%) were both seropositive and PCR‐positive for HTLV‐I. Four HTLV‐I‐seronegative subjects were found to be positive for HTLV‐I proviral DNA by PCR. Of the 19 HTLV‐I–infected subjects (11 women, 8 men; mean age, 59 ± 16 years), 13 (68%) had spastic paraparesis of varying severity. There were no signs of myelopathy in the Mashhadi‐born subjects who were negative for HTLV‐I proviral DNA by PCR. None of the non‐Mashhadi Iranian Jews was seropositive or PCR‐positive for HTLV‐I proviral DNA, or had clinical signs of spastic paraparesis. Our study indicates a high incidence of HTLV‐I infection and spastic paraparesis in Mashhadi‐born Iranian Jews. Possible transmission mechanisms may be related to a high rate of infection in this closed community, or to a genetically transmitted virus in a susceptible high‐inbred population.