Serum immunologic markers in multiple sclerosis patients on continuous combined therapy with beta-interferon 1a, prednisone and azathioprine

Break-through symptoms (BTS) in multiple sclerosis (MS) patients on beta-interferon (beta-IFN) monotherapy are most frequently treated with a brief administration of steroids. Here, we report the results of monitoring serum immunologic markers recorded at three-month intervals for 1.5 years in responders to beta-INF 1a (Avonex) monotherapy ( n = 21) and MS patients placed on Avonex with prednisone ( n = 83) and Avonex, prednisone and azathioprine (AZA) ( n = 21) because of BTS. Compared to 23 healthy controls, patients on Avonex monotherapy and Avonex with prednisone, in individuals on Avonex, prednisone and AZA, a significant decrease in serum concentration of soluble intercellular adhesion molecule-1 (sICAM-1) ( P = 0.001) was established. Combined therapy with Avonex, prednisone and AZA was associated with a significant increase in the serum level of interleukin (IL)10 ( P < 0.001). Compared to Avonex monotherapy, combined therapy suppressed the serum level of IL12p40, antagonized elevation in the serum concentration of soluble IL2 receptor (sIL2R) and inhibited an increase in the serum soluble CD95 (sCD95) molecule. In patients studied, no significant differences in the serum level of IL18 and tumor necrosis factor-α (TNF-α) were established. These findings are important in understanding some of the immunoregulatory mechanisms induced by combined therapy in MS.

Genetic predisposition to external apical root resorption in orthodontic patients: linkage of chromosome-18 marker

External apical root resorption (EARR) is a common orthodontic treatment sequela. Previous studies implicate a substantial genetic component for EARR. Using a candidate gene approach, we investigated possible linkage of EARR associated with orthodontic treatment with the TNSALP, TNFalpha, and TNFRSF11A gene loci. The sample was comprised of 38 American Caucasian families with a total of 79 siblings who completed comprehensive orthodontic treatment. EARR was assessed by means of pre- and post-treatment radiographs. Buccal swab cells were collected for extraction and analysis of DNA. No evidence of linkage was found with EARR and the TNFalpha and TNSALP genes. Non-parametric sibling pair linkage analysis identified evidence of linkage (LOD = 2.5; p = 0.02) of EARR affecting the maxillary central incisor with the microsatellite marker D18S64 (tightly linked to TNFRSF11A). This indicates that the TNFRSF11A locus, or another tightly linked gene, is associated with EARR.

Self-reported subjective perception of intoxication reflects family history of alcoholism when breath alcohol levels are constant

BACKGROUND

The premise of this study is that the increased familial risk for alcoholism is associated with genetic determinants of the response to alcohol, characterized by sensitivity and adaptation. Following a single administration, sensitivity is the initial response to alcohol, expressed as the change in dependent measures from baseline. Adaptation of dependent measures within a single exposure to alcohol can be expressed as acute tolerance (recovery of dependent measures toward baseline values) or sensitization (movement of dependent measure further away from baseline values). This study tested the hypothesis that family history-positive (FHP) subjects are more sensitive and more adaptive to alcohol compared with family history-negative (FHN) subjects.

METHODS

The initial response and development of adaptation to alcohol were assessed by using self-reported subjective perceptions during a breath alcohol concentration (BrAC) clamp of 60 mg%. The Biphasic Alcohol Effects Scale, the Sensation Scale and a visual analog scale of intoxication were acquired at baseline, after the BrAC clamp was established, and after maintenance of the clamp for 105 min.

RESULTS

FHP subjects were more sensitive to alcohol compared with FHNs, as evidenced by greater changes in feelings of intoxication when the BrAC clamp was initially achieved. While the clamp was maintained, the FHP subjects adapted to the effects of alcohol and their perceptions of intoxication became indistinguishable from those of the FHN subjects. The FHP subjects had developed acute tolerance to alcohol, whereas the FHN subjects did not. Other self-reported perceptions of alcohol's effects did not distinguish between the groups.

CONCLUSIONS

A differential family history of alcoholism was reflected in self-reported subjective perceptions of intoxication when the brain's exposure to a specified concentration of alcohol was held constant (BrAC of 60 mg%). FHP subjects reported greater intoxication after alcohol and subsequently developed acute tolerance to alcohol compared with FHN subjects.

Use of variable marker density, principal components, and neural networks in the dissection of disease etiology

Several approaches were taken to identify the loci contributing to the quantitative and qualitative phenotypes in the Genetic Analysis Workshop 12 simulated data set. To identify possible quantitative trait loci (QTL), the quantitative traits were analyzed using SOLAR. The four replicates identified as the "best replicates" by the simulators, 42, 25, 33, and 38, were analyzed separately. Each of the five quantitative phenotypes was analyzed individually in the four replicates. To increase the power to detect QTL with pleiotropic effects, principal component analysis was performed and one new multivariate phenotype was estimated. In each instance, after performing a 10-cM genome screen, fine mapping was completed in the initially identified linked regions to further evaluate the evidence for linkage. This approach of initially performing a coarse marker screen followed by analyses using much higher marker density successfully identified all the QTL playing a role in the quantitative phenotypes. The principal component phenotype did not substantially improve the power of QTL detection or localization. A neural network approach was utilized to identify loci contributing to disease status. The neural network technique identified the strongest gene influencing disease status as well as a locus contributing to quantitative traits 3 and 4; however, the inputs that contributed the greatest information were markers not in QTL regions.

Evidence for a locus on chromosome 1 that influences vulnerability to alcoholism and affective disorder

OBJECTIVE

Depression (major depression or depressive syndrome) is more prevalent in alcoholic than in nonalcoholic subjects in families with multiple members with alcoholism studied as part of the Collaborative Study on the Genetics of Alcoholism (National Institute on Alcohol Abuse and Alcoholism). First-degree relatives of probands with comorbid alcoholism and depression have a higher prevalence of both disorders than relatives of probands with alcoholism alone, and both groups have a higher prevalence than the relatives of comparison subjects selected without regard to psychopathology. Data from the collaborative study were used to test three phenotypes (comorbid alcoholism and depression, alcoholism or depression, and depression) for genetic linkage.

METHOD

Genome-wide sibling-pair linkage analyses were performed with the phenotypes comorbid alcoholism and depression, alcoholism or depression, and depression (major depression or depressive syndrome). Analyses were performed in two data sets (initial and replication data sets) from subject groups ascertained with identical criteria, as well as in the combined data set.

RESULTS

Peak lod scores on chromosome 1 (near 120 centimorgan) for the alcoholism or depression phenotype were 5.12, 1.52, and 4.66 in the initial, replication, and combined data sets, respectively. The corresponding lod scores on chromosome 2 were 2.79, 0.20, and 3.26; on chromosome 6, they were 3.39, 0.00, and 0.92; and on chromosome 16, they were 3.13, 0.00, and 2.06. Lod scores on chromosome 2 for the comorbid alcoholism and depression phenotype in the three data sets were 0.00, 4.12, and 2.16, respectively.

CONCLUSIONS

The results suggest that a gene or genes on chromosome 1 may predispose some individuals to alcoholism and others to depression (which may be alcohol induced). Loci on other chromosomes may also be of interest.

A genome-wide search for genes that relate to a low level of response to alcohol

BACKGROUND

The low level of response (LR) to alcohol is genetically influenced in both humans and animals, and a low LR is a characteristic of offspring of alcoholics that has been reported to predict alcoholism 10 and 15 years later. The genes that contribute to a low LR have not yet been identified.

METHODS

A 12-item questionnaire that measures LR, the Self Rating of the Effects of Alcohol (SRE) instrument, was filled out by 745 individuals from the Collaborative Study on the Genetics of Alcoholism (COGA) for whom genetic material was available. These subjects were genotyped by using 336 markers with an average heterozygosity of 0.74 and an average intermarker distance of 10.5 cM. Both quantitative and qualitative nonparametric, sib-pair analyses were carried out for the SRE measure related to early drinking experiences.

RESULTS

Correlations of SRE scores across related individuals were significant and between 0.16 and 0.22 for most values, compared with nonsignificant correlations of 0.03 or less among unrelated individuals. Linkage analyses performed by using the FIRST 5 variables (first five times alcohol is consumed) identified four chromosomal regions with lod scores > or = 2.0 whose maximum was also near a marker. One of these chromosomal regions previously was linked to alcohol dependence in the COGA sample.

CONCLUSIONS

These data document the familial nature of a low LR to alcohol as measured by the SRE and suggest several chromosomal regions that might contribute to the phenomenon.

Alcoholism susceptibility loci: confirmation studies in a replicate sample and further mapping

BACKGROUND

There is substantial evidence for a significant genetic component to the risk for alcoholism. A previous study reported linkage to chromosomes 1, 2, and 7 in a large data set that consisted of 105 families, each with at least three alcoholic members.

METHODS

Additional genotyping in the 105 families has been completed in the chromosomal regions identified in the initial analyses, and a replication sample of 157 alcoholic families ascertained under identical criteria has been genotyped. Two hierarchical definitions of alcoholism were employed in the linkage analyses: (1) Individuals who met both Feighner and DSM-III-R criteria for alcohol dependence represented a broad definition of disease; and (2) individuals who met ICD-10 criteria for alcoholism were considered affected under a more severe definition of disease.

RESULTS

Genetic analyses of affected sibling pairs supported linkage to chromosome 1 (LOD = 1.6) in the replication data set as well as in a combined analysis of the two samples (LOD = 2.6). Evidence of linkage to chromosome 7 increased in the combined data (LOD = 2.9). The LOD score on chromosome 2 in the initial data set increased after genotyping of additional markers; however, combined analyses of the two data sets resulted in overall lower LOD scores (LOD = 1.8) on chromosome 2. A new finding of linkage to chromosome 3 was identified in the replication data set (LOD = 3.4).

CONCLUSIONS

Analyses of a second large sample of alcoholic families provided further evidence of genetic susceptibility loci on chromosomes 1 and 7. Genetic analyses also have identified susceptibility loci on chromosomes 2 and 3 that may act only in one of the two data sets.