APOE epsilon variation in multiple sclerosis susceptibility and disease severity: some answers

BACKGROUND

Previous studies have examined the role of APOE variation in multiple sclerosis (MS), but have lacked the statistical power to detect modest genetic influences on risk and disease severity. The meta- and pooled analyses presented here utilize the largest collection, to date, of MS cases, controls, and families genotyped for the APOE epsilon polymorphism.

METHODS

Studies of MS and APOE were identified by searches of PubMed, Biosis, Web of Science, Cochrane Review, and Embase. When possible, authors were contacted for individual genotype data. Meta-analyses of MS case-control data and family-based analyses were performed to assess the association of APOE epsilon genotype with disease risk. Pooled analyses of MS cases were also performed to assess the influence of APOE epsilon genotype on disease severity.

RESULTS

A total of 22 studies (3,299 MS cases and 2,532 controls) were available for meta-analysis. No effect of epsilon2 or epsilon4 status on MS risk was observed (summary OR 1.14, 95% CI 0.96-1.34 and OR 0.89, 95% CI 0.78-1.01). Results obtained from analyses of APOE genotypes in 1,279 MS families were also negative (p = 0.61). Finally, results from pooled analyses of 4,048 MS cases also argue strongly that APOE epsilon status does not distinguish a relapsing-remitting from primary progressive disease course, or influence disease severity, as measured by the Expanded Disability Status Scale and disease duration.

CONCLUSION

Overall, these findings do not support a role for APOE in multiple sclerosis, and underscore the importance of using large sample sizes to detect modest genetic effects, particularly in studies of genotype-phenotype relationships.

Multiple Sclerosis Severity Score: Using disability and disease duration to rate disease severity

BACKGROUND

There is no consensus method for determining progression of disability in patients with multiple sclerosis (MS) when each patient has had only a single assessment in the course of the disease.

METHODS

Using data from two large longitudinal databases, the authors tested whether cross-sectional disability assessments are representative of disease severity as a whole. An algorithm, the Multiple Sclerosis Severity Score (MSSS), which relates scores on the Expanded Disability Status Scale (EDSS) to the distribution of disability in patients with comparable disease durations, was devised and then applied to a collection of 9,892 patients from 11 countries to create the Global MSSS. In order to compare different methods of detecting such effects the authors simulated the effects of a genetic factor on disability.

RESULTS

Cross-sectional EDSS measurements made after the first year were representative of overall disease severity. The MSSS was more powerful than the other methods the authors tested for detecting different rates of disease progression.

CONCLUSION

The Multiple Sclerosis Severity Score (MSSS) is a powerful method for comparing disease progression using single assessment data. The Global MSSS can be used as a reference table for future disability comparisons. While useful for comparing groups of patients, disease fluctuation precludes its use as a predictor of future disability in an individual.

A whole genome screen for association with multiple sclerosis in Portuguese patients

Multiple sclerosis (MS) is common in Europe affecting up to 1:500 people. In an effort to identify genes influencing susceptibility to the disease, we have performed a population-based whole genome screen for association. In this study, 6000 microsatellite markers were typed in separately pooled DNA samples from MS patients (n=188) and matched controls (n=188). Interpretable data was obtained from 4661 of these markers. Refining analysis of the most promising markers identified 10 showing potential evidence for association.

Desensitization of bladder sensory fibers by intravesical resiniferatoxin, a capsaicin analog: long-term results for the treatment of detrusor hyperreflexia

OBJECTIVES

To assess the pungency and the desensitizing effects of intravesical resiniferatoxin, an ultrapotent capsaicin analog, in patients with detrusor hyperreflexia.

METHODS

Fourteen patients with detrusor hyperreflexia were instilled during 30 min, without any form of local anesthesia, with 100 ml (or the bladder capacity if lower than that volume) of 50 or 100 nM resiniferatoxin solutions in 10% alcohol in saline. Patients were evaluated by voiding chart and urodynamic tests (volume to first contraction, maximal cystometric capacity, maximal detrusor pressure, icewater test) at 14, 30, 60, and 90 days and every 3 months thereafter

RESULTS

Resiniferatoxin instillation did not evoke pain or temporary worsening of urinary symptoms. Treatment improved or abolished incontinence in 9 out of 12 incontinent patients. Mean urinary frequency decreased from 14.2+/-6.4 to 10.3+/-3.2 at 3 months (p = 0.01). At this time point, mean maximal cystometric capacity increased from 182.3+/-119.8 to 330.0+/-201.6 ml (p = 0.01) and the ice water test, positive in 13 cases, became negative in 8 of them. Maximal detrusor pressure was not modified by the treatment. The effect was long-lasting, reaching 12 months in 7 cases.

CONCLUSIONS

The absence of irritative symptoms during bladder instillation of resiniferatoxin and the rapid onset of desensitization make this vanilloid superior to capsaicin for the treatment of detrusor hyperreflexia.

Desensitization of bladder sensory fibers by intravesical capsaicin has long lasting clinical and urodynamic effects in patients with hyperactive or hypersensitive bladder dysfunction

PURPOSE

Capsaicin was used to treat symptomatic patients with hyperactive or hypersensitive bladders.

MATERIALS AND METHODS

Capsaicin solution (1 mM.) was instilled into the bladder of 16 patients with spinal hyperreflexia, bladder instability or hypersensibility.

RESULTS

Frequency decreased in 14 patients and continence was achieved in 10 of 14 incontinent cases. Mean first desire to void and maximal cystometric capacity increased significantly. These effects lasted for 6 to 12 months and were renewed following repeat treatment.

CONCLUSIONS

Bladder afferent desensitization with capsaicin is promising in patients with motor or sensory bladder dysfunction, although initial pungency might limit its use.

[The effect of a protein-free diet on insulin and somatostatin secretion in rats]

We have used a model of experimental protein-energy malnutrition induced in weaned rats by administration of a protein free diet during 2 weeks. Some malnourished rats were then refed with a control diet for 4, 9 or 30 days. Control rats were fed for the same periods with the balanced control diet. Malnourished rats showed a loss in body weight of approximately 25%. After 30 days of refeeding, the animals gained weight reaching values higher than that of control rats. Insulin secreted by perifused pancreatic slices from malnourished rats, was impaired in first and second glucose-induced secretory phases. Basal secretion was also diminished in incubation of pancreatic slices. When malnourished rats were refed for 4 days, basal insulin secretion reached control values. Stimulated insulin secretion was normalized at 9 and 30 days of refeeding. Our result on somatostatin (SRIF) secretion in malnourished rats showed basal hypersecretion and diminished first and second glucose-induced secretory phases. During refeeding basal SRIF secretion was normalized from day 4. On the contrary stimulated secretion was significantly increased at 4 and 9 days of refeeding, and on day 30 values did not differ from controls. In protein energy malnutrition, the disturbed hormonal state can represent adaptative mechanisms to the protein depletion and hormonal changes have also an essential role in refeeding.

Effect of low-quality dietary protein on the thymus of growing rats

The status of the thymus of growing rats fed for 45 days after weaning on a low-quality dietary protein (7.5% maize) was compared with that in an age-matched control group receiving a diet containing casein at the same concentration. At the end of the feeding period, body weight (bw) was determined and the thymus was removed; its weight and cell number and the mature T-cell population--characterized by the monoclonal antibody W3/13 using the indirect immunofluorescence technique--were determined. Thymus weight expressed as mg/bw0.75 (3.9 +/- 0.75 vs 7.7 +/- 2.0), cell number (4.4 +/- 2.2 vs 26.3 +/- 7.6), and the absolute number of W3/13+ T cells (1.59 +/- 0.75 vs 17.8 +/- 5.4) were significantly lower (p less than 0.0005) in the experimental group than in the control group. The results suggest severe atrophy of the thymus of weaning animals chronically fed a low-quality protein.

Hypothesis on the time course of antigen dependent changes in lymphoid organs proved by experimental data of depleted growing rats' mesenteric lymph nodes

The results described in this paper partially agree with the hypothesis that mesenteric lymph nodes (MLN) of depleted growing rats recover their antigen specific determinants after the oral administration of 20% casein for 5-9 days following the time course of antigen dependent changes observed in virgin lymph nodes. With respect to the 39 days old control group, depleted MLN showed a highly diminished number of mature T cells (W3/13+) as well as surface and intracellular alpha heavy chain (alpha s and alpha cit). The oral administration of a 20% casein diet during 5 days tends to restore the appearance of these determinants; however, normal values were not attained even if refeeding was continued for 9 days. The discrepancy between the proposed hypothesis and the observed results might be ascribed to: a) defective migration of T cells from thymus; b) the diminished number of TH cells involved in terminal differentiation; c) inability of B cells to respond to T cell-derived factors.

Double infection of the CNS with herpes simplex and mumps viruses. Serological and ultrastructural studies

Clinical, serological and ultrastructural features are described in a case of acute encephalitis. The ultrastructural study of brain biopsy specimens revealed herpes-and paramyxovirus-like particles in neurons and glial cells that were characterized as herpes simplex and mumps viruses by serological study in serum and CSF. Of the few cases previously reported with double encephalitis, this is the only one in which ultrastructural and serological evidence of combined brain infection has been found.

Local immunoglobulin synthesis and blood-brain barrier assessment in subacute sclerosing panencephalitis

The immunoglobulin synthesis within the central nervous system and the blood-brain barrier (BBB) function were evaluated in 6 patients with subacute sclerosing panencephalitis (SSPE) using the IgG index and a graphic method based on serum/CSF albumin, alpha 2-macroglobulin, and IgG quotients. A strong local production of IgG was documented by both methods in all 6 cases of SSPE. Concerning the graphic analysis, the decrease in the serum/CSF alpha 2-macroglobulin ratio disclosed BBB dysfunction in 2 cases of SSPE, suggesting, in the absence of the serum/CSF albumin quotient abnormalities, that a homeostatic mechanism for CSF proteins can cause changes in the CSF protein profile.

Protein patterns of the cerebrospinal fluid of 30 patients with subacute sclerosing panencephalitis (SSPE)

Lumbar cerebrospinal fluid (CSF) from 30 cases of subacute sclerosing panencephalitis (SSPE) was studied for total protein and protein electrophoresis. Total CSF protein values were normal in almost all the cases, but the gamma-globulin was increased and had an oligoclonal morphology in all the cases. Absolute and relative values of some of the other electrophoretic fractions were decreased. Total protein and electrophoretic serum values in 25 cases did not differ significantly from the controls, although the gamma-globulin presented an oligoclonal morphology in 13 cases. CSF immunoglobulins were determined in 10 cases; IGG was increased in ll; IgA was traceable and slightly increased in only four cases; IgM was not found. These findings point to the intrathecal synthesis of IgG and the absence of barrier impairment. The decrease of the absolute values of some of the other CSF proteins suggests that homeostatic mechanisms for protein concentration in the CSF are maintained in SSPE.

Influence of growth rate on the ability of hypertransfusion induced plethora to suppress erythropoiesis in the growing rat

To induce different rates of growth male rats 23 days of age were places on diets containing no protein or 20% casein for 10 days. They were then divided into three subgroups which were placed on diets containing 5%, 10% or 20% casein until the end of the experimental period (day 17). Adult rats were used as controls. Rats were hypertransfused on days 8 and 9 and RBC-59Fe uptake determined on day 17. Body weight was directly correlated with the casein content of the diet in the growing rats. RBC-radioiron incorporation was also influenced by the protein content of the diet in the young rats in spite of the fact that hematocrits were over 60% in all the animals. On the contrary, 59Fe uptake by erythrocytes was not related to diet composition in the adult rats. When radioiron incorporation values were plotted against growth rate it became evident that a close direct correlation exists between erythropoiesis and growth rate in transfused-polycythemic rats, indicating that the degree of suppression of red cell production provoked by hypertransfusion-induced plethora is dependent on the rate of growth of the animal, keeping with it an inverse relationship.

Oligoclonal gamma-globulin of cerebrospinal fluid in neurobrucellosis

The clinical manifestations and laboratory findings of two cases of neurobrucellosis are described. The cerebrospinal fluid (CSF) protein electrophoresis showed increased gamma-globulins and decreased relative values of pre-albumin and albumin, associated to high values of total CSF protein. The evidence of oligoclonal morphology of CSF gamma-globulins suggests that part of them had an intrathecal origin, in addition to an increased crossing of the damaged blood-CSF barrier. Similar oligoclonal appearance of CSF gamma-globulins was observed in two additional cases of neurobrucellosis previously reported.

Effect of maternal dietary amino acid pattern on rat offspring

The effect of lifetime feeding to gravid rats of diets containing different indispensable amino acid patterns on body and brain composition of the offspring was studied. Two groups of rats were fed, from weaning to delivery, either experimental diet B or diet I. Both diets contained the same amount of total nitrogen (3.14%), available lysine (0.4%) and "complete protein to total protein ratio" (22.5%), but whereas diet I provided an excess of indispensable amino acids over the amount of limiting amino acid, diet B supplied all of the indispensable amino acids in marginal amounts and in a rather well balanced pattern. The nitrogen content of diet B was matched to the nitrogen content of diet I by addition of a mixture of dispensable amino acids. A control group fed stock diet (C) was run simultaneously. Birth body weight, carcass nitrogen to water ratio, and brain weight of pups were significantly lower in B than in I. The figures for I were not significantly different from the controls. Brain DNA content in B was significantly lower than in C, but in I it was lower than for both B and C. Nitrogen to water ratio and brain DNA content of group B were low when compared to the standard curves for our colony; however, DNA content was normal for the degree of body development. On the other hand, in group I brain DNA was preferentially affected, as if body and brain maturity were dissociated.