Immunoregulatory circuits in multiple sclerosis: is there a "short"?

Intravenous immunoglobulin treatment in the prevention of childbirth-associated acute exacerbations in multiple sclerosis: a pilot study

Acute exacerbations frequently occur after childbirth in patients with relapsing-remitting multiple sclerosis (MS). The present pilot study was initiated in an attempt to reduce the number of childbirth-associated acute exacerbations in the postpartum period. We treated nine MS patients with a history of 12 childbirth-associated acute exacerbations that had occurred 2-9 weeks after previous deliveries. The patients were administered intravenous immunoglobulin (IVIg) at a dose of 0.4 g/kg per day for 5 consecutive days during the 1st week after childbirth and at 6 and 12 weeks thereafter. None of the treated patients relapsed during the 6-month period after delivery. However, three patients had a remote relapse, two at 8 months and one at 10 months after childbirth, but these probably represented the natural course of disease and were not associated with childbirth. We conclude that IVIg treatment may prevent acute childbirth-associated exacerbations in relapsing-remitting MS patients.

The involvement of specific anti myelin basic protein antibody-forming cells in multiple sclerosis immunopathology

Irrespective of the large body of literature on the putative role of antibodies in the development of multiple sclerosis (MS), the detection of specific antibody-forming B cells (AFCs) in the central nervous system (CNS) tissues has not been described. In this study we show that autoantigen-specific AFCs can be found in CSN tissue sections of MS patients. Applying a newly developed myelin basic protein (MBP)-enzyme conjugate technique, we have detected MBP-specific AFCs in autopsy periventricular white matter and cerebellum tissue sections of MS patients. We demonstrated the presence of MBP-specific AFCs in CNS tissue sections in five out of 12 MS patients. No MBP-specific AFCs were detected in CNS tissue sections of 11 patients with other neurological diseases, such as Parkinson's and Alzheimer's disease, or in brain tissue sections of eight deceased persons without neurological diseases. In MS patients, anti-MBP AFCs were present in brain tissue sections both with and without plaques. The proportion of MBP-specific AFCs in some of the MS patient brain tissues reached over 50% of all AFCs. The high relative frequency of the anti-MBP AFCs and their localization in periventricular white matter and cerebellum of MS patients only, suggests that anti-MBP AFCs represent a cell population, which could play an important role in MS immunopathology.

Multiple sclerosis and latitude: a new perspective on an old association

For 68 years latitude has been identified as an important risk factor in the occurrence of multiple sclerosis (MS), but not satisfactory explanation has been offered for this relationship. Epidemiological studies of MS, however, have failed to take into account the degree of change in the amount of ambient light over the course of the year, a variable which is closely related to photoperiod and latitude. Seasonal affective disorder (SAD), another illness for which latitude is a risk factor, appears to be related to the decrease in ambient light during the winter months, and offers some relevant insights into the geographical distribution of risk for developing MS. Researchers have found a relationship between degree of reported seasonal difficulties in a population sample and altered immunological function. Furthermore, the effects of bright light on mood have been shown to be regulated through the eye. We hypothesize that the risk of developing MS is related to impairment of the immune system caused by light deprivation prior to adulthood.

T-lymphocyte subpopulations in acute unilateral optic neuritis

The authors prospectively analyzed T-lymphocyte subpopulations in the peripheral blood of nine patients with acute unilateral optic neuritis and compared them with 25 controls without neurologic disease. The presence or absence of alterations in circulating T-cell subsets has not been examined previously in patients with isolated optic neuritis. The authors found the mean ratio of inducer (CD4) to suppressor (CD8) T-lymphocytes was 2.07 +/- 0.51 for the group with optic neuritis, statistically indistinguishable from a value of 1.78 +/- 1.04 for the control group. Multiple sclerosis (MS) subsequently developed in one patient. Her inducer/suppressor T-cell ratio was initially 2.66, but progressively increased to 3.68 concomitant with the clinical manifestation of focal neurologic signs. Although optic neuritis may be the initial clinical sign of MS, the periodic alteration of circulating T-lymphocytes increasing the inducer/suppressor T-cell ratio in MS was not observed in those with isolated optic neuritis.

Multiple sclerosis: why?

Multiple sclerosis is a chronic inflammatory demyelinating condition of the nervous system. Its etiology is obscure. Something in the environment strikes a susceptible host. Somehow the immune system produces central nervous system lesions. Magnetic resonance imaging scans show far greater "lesion" formation in the brain than was expected from clinical exacerbations. White blood cell changes suggest the disease is not entirely localized to the CNS. Some immunomodulatory treatments temporarily slow the rate of deterioration.

Immune mechanisms in the pathogenesis of demyelinating diseases

The loss of myelin which characterises many human and experimental demyelinating diseases, among them multiple sclerosis, is thought to be immune mediated, but the precise mechanisms responsible remain unknown despite intense research. Normally, myelin in the central nervous system (CNS) is protected from systemic immune responses by the blood brain barrier, which separates nervous tissue from the peripheral circulation. Here we review evidence suggesting that an understanding of the demyelinating disorders may be helped by considering their immune pathogenesis in two stages. The first is damage to the blood brain barrier; this appears to be cell mediated, and allows infiltration into the CNS of other immune effectors. These include complement and also macrophages, which together may mediate the second stage, injury to the myelin/oligodendrocyte complex.