title: Familial clusters of HTLV-1-associated myelopathy/tropical spastic paraparesis.
abstract: OBJECTIVE
  HTLV-1 proviral loads (PVLs) and some genetic factors are reported to be associated with the development of HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). However, there are very few reports on HAM/TSP having family history. We aimed to define the clinical features and laboratory indications associated with HAM/TSP having family history.
  
  
  METHODS
  Records of 784 HAM/TSP patients who were hospitalized in Kagoshima University Hospital and related hospitals from 1987 to 2012 were reviewed. Using an unmatched case-control design, 40 patients of HAM/TSP having family history (f-HAM/TSP) were compared with 124 patients suffering from sporadic HAM/TSP, who were admitted in series over the last 10 years for associated clinical features.
  
  
  RESULTS
  Of the 784 patients, 40 (5.1%) were f-HAM/TSP cases. Compared with sporadic cases, the age of onset was earlier (41.3 vs. 51.6 years, p<0.001), motor disability grades were lower (4.0 vs. 4.9, p = 0.043) despite longer duration of illness (14.3 vs. 10.2 years, p = 0.026), time elapsed between onset and wheelchair use in daily life was longer (18.3 vs. 10.0 years, p = 0.025), cases with rapid disease progression were fewer (10.0% vs. 28.2%, p = 0.019), and protein levels in cerebrospinal fluid (CSF) were significantly lower in f-HAM/TSP cases (29.9 vs. 42.5 mg, p<0.001). There was no difference in HTLV-1 PVLs, anti-HTLV-1 antibody titers in serum and CSF, or cell number and neopterin levels in CSF. Furthermore, HTLV-1 PVLs were lower in cases with rapid disease progression than in those with slow progression in sporadic cases [corrected]
  
  
  CONCLUSIONS
  We demonstrated that HAM/TSP aggregates in the family, with a younger age of onset and a slow rate of progression in f-HAM/TSP cases compared with sporadic cases. These data also suggested that factors other than HTLV-1 PVLs contribute to the disease course of HAM/TSP.
authors.affiliation: Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima city, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nozuma
authors.affiliation: Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima city, Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Matsuura
authors.affiliation: Department of Molecular Pathology, Center for Chronic Viral Diseases, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima city, Japan.
authors.forename: Toshio
authors.initials: T
authors.lastname: Matsuzaki
authors.affiliation: Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima city, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Watanabe
authors.affiliation: Department of Molecular Pathology, Center for Chronic Viral Diseases, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima city, Japan.
authors.forename: Ryuji
authors.initials: R
authors.lastname: Kubota
authors.affiliation: Department of Molecular Pathology, Center for Chronic Viral Diseases, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima city, Japan.
authors.forename: Shuji
authors.initials: S
authors.lastname: Izumo
authors.affiliation: Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima city, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Takashima
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002648:Child; D005190:Family; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015493:Paraparesis, Tropical Spastic / Q000175:diagnosis / Q000453:epidemiology*