Absence of HTLV-1 related sequences in MS from high prevalence areas in western Norway

HTLV-1 and its neurological complications

BACKGROUND

Since its discovery in 1980, human T-cell lymphotropic virus type-1 (HTLV-1) has been associated with a number of neurological diseases. The distribution of HTLV-1-associated neurological disease is worldwide. In endemic areas, up to 30% of the population may be infected with HTLV-1; however, only a small percentage of infected persons develops neurological disease.

REVIEW SUMMARY

In 1986, HTLV-1 infection was reported in patients of chronic progressive myelopathy of uncertain etiology, and the disease entity was called HTLV-1-associated myelopathy/tropical spastic paraparesis. Recently, HTLV-1 infection has been associated with polymyositis and uveitis. Interestingly, a single patient may display more than one syndrome. Although other neurological syndromes occur in HTLV-1-infected individuals, there is not enough epidemiologic data that show a strong association. Treatment of HTLV-1-associated neurological disease is challenging, and well-controlled studies are lacking.

CONCLUSION

As neurologists and other scientists begin to understand the pathophysiology of HTLV-1 infection, improved therapies should be developed. Randomized trials with longer follow-up are required to understand the effect of treatment on disability and quality of life.

Multiple sclerosis and cancer in Norway. A retrospective cohort study

INTRODUCTION

During the extended course of multiple sclerosis (MS) there are ample opportunities for the patients to develop other illnesses including cancer, a potential long-term complication of the immunosuppressive drug treatment in MS.

MATERIAL AND METHODS

A retrospective cohort study was done to estimate the relative risk of cancer in a population of MS-patients from three Norwegian counties by record linkage with the Cancer Registry of Norway. The cohort comprised 1271 MS-patients, 530 men and 741 women, identified in five longitudinal population-based incidence studies. The reporting of cancer cases has been compulsory in Norway since 1952.

RESULTS

We found 73 cancer cases (standardized incidence ratio (SIR) = 0.86, 95% CI 0.68-1.09). Mean follow-up time was 18.4 years. A significant excess of breast cancers was observed (SIR = 1.70, 95% CI 1.05-2.60). A non-significant excess of cancer in the urinary tract was observed. No significantly increased risk in hematologic and lymphatic malignancies or malignant brain tumors was observed. The incidence of cancer of the digestive organs was significantly lower than expected (SIR = 0.51, 95% CI 0.24-0.93).

CONCLUSION

Overall, the study indicates that an MS-patient is not at any unusual risk for subsequent development of cancer compared to the normal population.

Is there a case for a virus aetiology in multiple sclerosis?

Multiple Sclerosis (MS) is a devastating demyelinating disease with a very high prevalence in North-East Scotland and in the Orkney and Shetland Islands. MS appears to be a multifactorial disorder with environmental and genetic elements and it has been proposed that these, in tandem, provoke an autoimmune response giving rise to the disease. Although there is no direct evidence of a specific virus being involved in MS, there are nevertheless grounds for suspecting a viral association. This review discusses these aspects of MS and suggests that a more aggressive approach to unravelling the role of viruses is needed.