A population-based study comparing multiple sclerosis clinic users and non-users in British Columbia, Canada

BACKGROUND AND PURPOSE

Much clinical knowledge about multiple sclerosis (MS) has been gained from patients who attend MS specialty clinics. However, there is limited information about whether these patients are representative of the wider MS population. The objective of this study was to compare incident MS cases who were MS clinic users to non-users of the specialty MS clinics in British Columbia, Canada.

METHODS

This was a retrospective record-linkage cohort study using prospectively collected data from the British Columbia Multiple Sclerosis database and province-wide health administrative databases.

RESULTS

There were 2841 incident MS cases between 1996 and 2004 including 1648 (58%) that had registered at an MS clinic ('clinic cases') and 1193 (42%) that had not ('non-clinic cases'). Gender and socioeconomic status distributions were similar; however, non-clinic cases were older, accessed health services more frequently and had a higher burden of comorbidity than clinic cases. Only 1% of the non-clinic cases had filled a prescription for an MS-specific disease-modifying therapy, compared to 51% of the clinic cases.

CONCLUSIONS

Our findings have several important implications: even within a publicly funded healthcare system, a high proportion of individuals with MS may not access a specialty MS clinic; the needs of MS patients managed in the community may differ from those referred to an MS clinic; findings from studies involving clinic-based MS cohorts may not always be generalizable to the wider MS population; and access to population-based health administrative data offers the opportunity to gain a broader understanding of MS.

Genetic susceptibility to MS: a second stage analysis in Canadian MS families

Four published genome screens have identified a number of markers with increased sharing in multiple sclerosis (MS) families, although none has reached statistical significance. One hundred and five markers previously identified as showing increased sharing in Canadian, British, Finnish, and American genome screens were genotyped in 219 sibling pairs ascertained from the database of the Canadian Collaborative Project on Genetic Susceptibility to MS (CCPGSMS). No markers examined met criteria for significant linkage. Markers located at 5p14 and 17q22 were analyzed in a total of 333 sibling pairs and attained mlod scores of 2.27 and 1.14, respectively. The known HLA Class II DRB1 association with MS was confirmed (P<0.0001). Significant transmission disequilibrium was also observed for D17S789 at 17q22 (P=0.0015). This study highlights the difficulty of searching for genes with only mild-to-moderate effects on susceptibility, although large effects of specific loci may still be present in individual families. Future progress in the genetics of this complex trait may be helped by (1) focussing on more ethnically homogeneous samples, (2) using an increased number of MS families, and (3) using transmission disequilibrium analysis in candidate regions rather than the affected relative pair linkage analysis.

Blood mononuclear cells in patients with HTLV-I-associated myelopathy: lymphocytes are highly activated and adhesion to endothelial cells is increased

We have investigated lymphocyte subpopulations and blood mononuclear cell (MNC) adhesion to activated endothelial monolayers in patients with human T lymphotropic virus type I (HTLV-I) associated myelopathy (HAM), in HTLV-I asymptomatic carriers (carriers), and in seronegative controls. HAM patients and carriers had higher levels of CD4(+)CD29(+) "memory cells" than controls (P < 0.05). The percentage of CD3(+)CD27(-) "primed T cell" was elevated in patients with HAM (P < 0.05), but not in carriers. HAM patients had higher levels of CD8(+)CD57(+) "cytotoxic cells" (P < 0.05) than controls and carriers. The percentages of CD4(+) cells coexpressing activation markers HLA-DR and CD25, and of CD8(+) cells expressing HLA-DR, were significantly higher in HAM patients and carriers than in controls. Functional experiments indicated that MNC from HAM patients adhered more to activated endothelial monolayers than MNC from carriers or controls. Blocking studies demonstrated that the adhesion molecules VLA-4 and ICAM-1 and also L-selectin all contributed to increased binding. Analysis of expression of molecules involved in adhesion indicated that in HAM patients, L-selectin (CD62L) expression on CD4(+) and CD8(+) subsets was lower than in controls. Interestingly, HAM patients had a lower percentage of CD4(+) subsets expressing L-selectin than carriers (P < 0.05). In contrast, the percentage of CD4(+) and CD8(+) cells expressing VLA-4 (CD49d) was found to be higher in both HAM patients and carriers compared with controls. After 2 days in culture without mitogen, the percentage of T cells expressing ICAM-1 (CD54) increased in culture in carriers and more profoundly in HAM, but not in controls (P < 0. 05). After culture, T cells expressing the early activation antigen CD69 were also increased in HAM and carriers (P < 0.05) but not in controls. Interestingly, the levels of CD8(+) cells coexpressing activation antigen HLA-DR and CD38 were higher in HAM patients compared with both carriers and controls (P < 0.05) after culture. These findings are consistent with the observations that HTLV-I produces chronic lymphocyte activation with increased adhesion. This may be sufficient to initiate events leading to central nervous system inflammation and ultimately to HAM.

Pregnancy and multiple sclerosis. A prospective study

OBJECTIVE

To conduct a prospective assessment of pregnancy on women with multiple sclerosis (MS), focusing on pregnancy outcome and relapses during gestation and up to 6 months after delivery.

DESIGN

Expected numbers of relapses were based on data for (1) "self-controls": the mothers ("cases") themselves prior to becoming pregnant and (2) "matched controls": female patients with MS "matched" to the mothers for year of birth, age of MS onset, MS type, MS course, and initial MS symptom(s).

SETTING

Cases and controls were identified from an ambulatory care MS clinic that serves the province of British Columbia, Canada.

PATIENTS OR OTHER PARTICIPANTS

Women with a diagnosis of MS who attended the MS clinic during 1982 through 1986 and subsequently became pregnant during 1982 through 1989 inclusive were included in this study as cases. Matched controls were women with MS who attended the MS clinic during the same period but did not become pregnant.

RESULTS

No significant increase in relapse rate was found for cases during the first two trimesters of gestation. The number of relapses was significantly less than expected during the third trimester compared with matched controls (chi 2 = 6.80, df = 1, P < .02), but not compared with self-controls (chi 2 = 3.39, df = 1, P > .05). The observed number of relapses for the 6 months after delivery did not differ significantly from expected (self-controls: chi 2 = 2.84, df = 2, P > .05; matched controls: chi 2 = 1.76, df = 2, P > .05).

CONCLUSION

These data suggest that neither pregnancy nor the 6-month period after delivery is a risk factor for relapse in MS. They are consistent with previous observations that, in the long term, pregnancy does not influence subsequent MS disability.

Magnetic resonance imaging in the evaluation of clinical trials in multiple sclerosis

Magnetic resonance imaging (MRI) provides an objective method of evaluating multiple sclerosis clinical trials and is at least five times more sensitive to disease activity. In a recent clinical trial, MRI was also approximately twice as sensitive as clinical measurements to the treatment effect of a drug.

Progressive multiple sclerosis: abnormal immune functions in vitro and aberrant correlation with enumeration of lymphocyte subpopulations

In a series of 27 consecutive progressive multiple sclerosis (MS) patients under age 50 we have simultaneously measured 3 in vitro immune functions and 6 markers and compared their results to a group of 21 controls. We have confirmed a reduction of concanavalin A (Con A) -induced suppression and NK function contrasting with increased IgG secretion in response to pokeweed mitogen (PWM). Among 6 monoclonal antibody-recognized subpopulation (Leu 1, Leu 2, OKT8, Leu 3, Leu 7 and Leu 11) only Leu 2+ lymphocytes were statistically reduced. OKT8+ were slightly reduced, Leu 3+ were slightly increased. Discriminant analysis revealed that the 3 immune functions together with the results of OKT8 and Leu 3 enumeration were sufficient to appropriately classify most of the individuals. Only 3 MS and 4 controls were misclassified. Correlation analysis suggested disappearance of the doubly labelled OKT8/Leu 7 population in MS patients. In MS as opposed to controls Con A-induced suppression did not correlate with suppressor cell markers but correlated with NK cell markers suggesting that in MS this population mediates Con A-induced suppression. IgG secretion and Con A suppressor cell function were inversely correlated in MS patients but not in controls, suggesting that in chronic progressive multiple sclerosis a common abnormality underlies both increased response to PWM and decreased induction of suppression by Con A.

Suppressor T-lymphocytes in multiple sclerosis: analysis of patients with acute relapsing and chronic progressive disease

T cell-specific antigens as identified by the anti-Leu 1, anti-Leu 2a, and anti-Leu 3a monoclonal antibodies were quantitated in 31 normal control subjects, 21 adults with spinal cord injury, 58 patients with stable multiple sclerosis, 31 patients with chronic progressive multiple sclerosis, and 15 patients with multiple sclerosis in acute relapse. The only significant deviations from normal values were a slightly low mean T cell (Leu 1-positive) value in patients in acute relapse and a low suppressor T cell (Leu 2a-positive) mean value in patients with chronic progressive multiple sclerosis. We were unable to confirm previous studies using the OK series of monoclonal antibodies that reported low suppressor T cell levels (OKT5 and OKT8 positive) in patients with acute relapses. We suggest that modulation (a spontaneous or induced variability in the expression) of individual cell surface antigens may explain the differences seen between our study and other reported series.

Central nervous system infection and immune response in mice inoculated into the lip with herpes simplex virus type 1

Virus may be recovered from various areas of the central nervous system (CNS) of mice for as long as 11 days after inoculation of herpes simplex virus type 1 (HSV-1) into the lip. The probability of isolation from any particular region of the CNS seems to be a function of the distance of that area from the root-entry zone of the trigeminal nerve. It is also mouse strain-dependent, with much more extensive evidence of brain infection being found in BALB/c and C3H rather than C57BL/6 mice, in which it is limited to the pons. The virus could not be isolated from the CNS of BALB/c mice after 10 days, though HSV-1 is readily recovered from the trigeminal ganglia at least through day 38. Significant concentrations of HSV-1-specific immunoglobulin (Ig) were demonstrated consistently in cerebrospinal fluid (CSF) from day 12 after exposure to virus. The persistence of relatively high concentrations of IgM in the CSF indicates that much of this antibody may be synthesized locally in the brain.

Cytotoxic activity and interferon production by lymphocytes from patients with multiple sclerosis

Peripheral blood lymphocytes from MS patients and from healthy control donors were compared for their ability to mediate spontaneous and antibody-dependent cell-mediated cytotoxicity. They were also compared for their ability to respond to infection with various strains of measles and sSPE viruses with interferon production and enhanced NK activity. Neither SLMC nor ADCC against several different target cells was found to be impaired in the MS population. Furthermore, no defect was detected in the response of patients' lymphocytes to virus challenge in vitro in terms of both activation of NK cells and interferon production. Enhanced NK activity was also induced by an exogenous interferon preparation and by Poly I:C to the same extent in patients and controls.

Cytotoxic activity and interferon production by lymphocytes from patients with multiple sclerosis

Peripheral blood lymphocytes from MS patients and from healthy control donors were compared for their ability to mediate spontaneous and antibody-dependent cell-mediated cytotoxicity. They were also compared for their ability to respond to infection with various strains of measles and sSPE viruses with interferon production and enhanced NK activity. Neither SLMC nor ADCC against several different target cells was found to be impaired in the MS population. Furthermore, no defect was detected in the response of patients' lymphocytes to virus challenge in vitro in terms of both activation of NK cells and interferon production. Enhanced NK activity was also induced by an exogenous interferon preparation and by Poly I:C to the same extent in patients and controls.