Influence of the Number of Queens on Nest Establishment: Native and Invasive Ant Species

As a critical stage in the life cycle of ant colonies, nest establishment depends on external and internal factors. This study investigates the effect of the number of queens on queen and worker behavior during nest establishment in invasive Argentine ants (Linepitema humile) and native Mediterranean Tapinoma nigerrimum. We set up experimental colonies with the same number of workers but with one or six queens. At different time points, we recorded the positions of queens and workers inside and outside the nest. Our results highlight the influence of the number of queens on the position of queens and workers with between-species differences. Queens of both species entered the nests more quickly when there were six queens. During nest establishment, more workers were inside nests with six queens for both species, with this effect being greater for T. nigerrimum. Once nests were established, fewer workers of both species were engaged in nest maintenance and feeding in nests with six queens; T. nigerrimum had fewer workers engaged in patrolling. These results suggest that the number of queens is a key factor driving queen and worker behavior during and after nest establishment with different species responses.

The CD4+ T-cell subset lacking expression of the CD28 costimulatory molecule is expanded and shows a higher activation state in multiple sclerosis

Multiple sclerosis (MS) is a chronic debilitating disease, in which T-cells are considered to play a pivotal role. CD28 is the quintessential costimulatory molecule on T-cells and its expression declines progressively with repeated stimulations, leading to the generation of CD28(-) T-cells. Our aim was to examine whether CD4(+)CD28(-) T-cells were enriched in MS patients, and characterize the phenotype of this subset in MS patients and healthy controls (HC). All these changes could provide these CD4(+)CD28(-) T-cell characteristics that might be involved in the pathogenesis of MS, turning this T-cell subset into a potential target for future therapeutic strategies.

Validation of the spanish version of the Multiple Sclerosis International Quality of Life (Musiqol) questionnaire

Background

The Multiple Sclerosis International Quality Of Life (MusiQoL) questionnaire, a 31-item, multidimensional, self-administrated questionnaire that is available in 14 languages including Spanish, has been validated using a large international sample. We investigated the validity and reliability of the Spanish version of MusiQoL in Spain.

Methods

Consecutive patients with different types and severities of multiple sclerosis (MS) were recruited from 22 centres across Spain. All patients completed the MusiQoL questionnaire, the 36-Item Short Form (SF-36) health survey, and a symptoms checklist at baseline and 21 days later. External validity, internal consistency, reliability and reproducibility were tested.

Results

A total of 224 Spanish patients were evaluated. Dimensions of MusiQoL generally demonstrated a high internal consistency (Cronbach's alpha: 0.70-0.92 for all but two MusiQoL domain scores). External validity testing revealed that the MusiQoL index score correlated significantly with all SF-36 dimension scores (Pearson's correlation: 0.46-0.76), reproducibility was satisfactory (intraclass correlation coefficient: 0.60-0.91), acceptability was high, and the time taken to complete the 31-item questionnaire was reasonable (mean [standard deviation]: 9.8 [11.8] minutes).

Conclusions

The Spanish version of the MusiQoL questionnaire appears to be a valid and reliable instrument for measuring quality of life in patients with MS in Spain and constitutes a useful instrument to measure health-related quality of life in the clinical setting.

Multiple sclerosis prevalence in Malaga, Southern Spain estimated by the capture–recapture method

Background: Although not definitively proven, there is commonly accepted to be a latitudinal gradient in the distribution of multiple sclerosis (MS), which is more frequent in temperate zones. The European Mediterranean countries are situated in a zone of median frequency, although ever increasing figures have been noted in the last decades.

Objective: The objective of this study was to assess the current prevalence rate of MS in the province of Malaga, Southern Spain.

Methods: The capture–recapture method (CRM) uses independent sources of data and permits the number of non-registered cases of a given disease to be estimated, and by doing so, to avoid ascertainment bias.

Results: Use of this method showed the estimated prevalence rate of MS in the province of Malaga, Southern Spain, to be 125/105 (95% confidence interval: 102/105–169/105), higher than the figures published previously.

Conclusions: Although we recognize that these data need to be confirmed in further studies and in other areas of the country using a similar method, we believe this study is the first to find such high figure of prevalence, being very similar to the figures reported in recent years in other southern European countries.

Kinetics and incidence of anti-natalizumab antibodies in multiple sclerosis patients on treatment for 18 months

Natalizumab is a monoclonal antibody shown to be highly effective in the treatment of relapsing–remitting multiple sclerosis (RRMS). Patients treated with natalizumab can develop antibodies directed against this agent that may affect the efficacy and safety of the drug. In this observational study, the kinetics of the appearance and the incidence of anti-natalizumab antibodies were followed prospectively for 18 months in a cohort of 64 consecutive patients treated with natalizumab for relapsing MS. Blood samples were drawn immediately before starting natalizumab therapy and each month afterwards. The presence of antibodies against natalizumab was assessed by enzyme-linked immunosorbent assay (ELISA) in all patients. Anti-natalizumab antibodies were detected in nine (14.1%) natalizumab-treated patients, three (4.68%) of whom were transiently positive while six (9.37%) were persistently positive (these patients discontinued natalizumab). All positive titres were observed during the first 4 months of treatment. One patient with a hypersensitivity reaction also had persistent antibodies. We conclude that antibodies against natalizumab develop early, within the first 6 months of therapy with natalizumab. Although no antibodies were detected after 4 months of therapy in this particular study, this does not rule out their development later on in exceptional cases.

Gene expression in IFNß signalling pathway differs between monocytes, CD4 and CD8 T cells from MS patients

IFNß exerts its activity through the interaction with IFNAR, through activation of the JAK/STAT pathway. We analyzed the changes in IFNAR1, IFNAR2, STAT1, STAT2, Tyk2, JAK1, IRF9 and MxA gene expressions after prolonged IFNß treatment, in isolated mononuclear-cell subpopulations from MS patients, by real time PCR. The effect of IFNß on gene expression differed depending on the subpopulation assessed. The data suggest that CD8+ T cells are the most influenced by prolonged IFNß therapy as IFNAR2, Tyk2, IRF9 and Jak1 expressions were decreased, whereas MxA expression was increased in these cells.

The efficacy of natalizumab in patients with multiple sclerosis according to level of disability: results of an observational study

BACKGROUND

Little is known about how the level of disability at the start of treatment with natalizumab affects its efficacy.

OBJECTIVES

The aim of this study was to investigate the effect of natalizumab on relapses in patients with different levels of baseline disability associated with MS.

METHODS

This single-centre observational study collected demographic data for patients followed prospectively and who were scheduled to start natalizumab therapy due to the presence of disease activity. The annualized relapse rate (ARR) and Kurtzke Expanded Disability Status Scale scores were analysed for the previous year, on starting treatment (baseline) and 1 year after starting therapy.

RESULTS

Seventy-seven patients (mean age: 39.0 years, mean disease duration: 12.4 years) were included. The difference between ARR before and after starting treatment was 0.92 for baseline Expanded Disability Status Scale ≤ 3.5 (p < 0.0005), 0.70 for Expanded Disability Status Scale 4.0-6.0 (p < 0.007) and 0.57 for Expanded Disability Status Scale ≥ 6 (p = 0.386). Expanded Disability Status Scale did not vary during the study. One patient discontinued treatment due to an adverse event and nine patients discontinued due to positive anti-natalizumab antibodies.

CONCLUSIONS

The findings support the efficacy of natalizumab in reducing ARR in the year after starting treatment in patients with baseline Expanded Disability Status Scale ≤ 6.

Neutralizing antibodies against IFN beta in patients with multiple sclerosis: a comparative study of two cytopathic effect tests (CPE) for their detection

Neutralizing antibodies (NABs) against IFN beta should be measured in specialized laboratories, using a test of inhibition of the cytopathic effect (bioassay or CPE test), based on the capacity of IFNss to block the infection of live monolayer-cultured cells by a virus, depending on the presence or absence of NABs. The European Federation of Neurological Societies (EFNS) considers this assay to be the gold standard. However, the various different ways to perform this assay complicate comparison of the results between laboratories. The World Health Organization (WHO) has published several recommendations to perform this assay using the A549 cell line and the murine encephalomyocarditis virus (EMCV). In order to validate the results previously obtained in our laboratory with HEP2/VSV, we undertook a comparative analysis of the two bioassays, HEP2/VSV and A549/EMCV, to assess whether the use of different cell lines and viruses influences sensitivity. We also calibrated the A549/EMCV assay with a reference IFNss. Our results confirm that the bioassay with HEP2/VSV is as sensitive as the assay with A549/EMCV and that a significant association and correlation exist in the results between both assays. Thus, past results with HEP2/VSV in our laboratory could be comparable with those obtained with A549/EMCV in both our laboratory and others.

Interferon receptor expression in multiple sclerosis patients

To determine the gene expression of IFNAR1, IFNAR2 and MxA protein and the association with IFNbeta treatment response in MS patients. MS patients treated with IFNbeta had a significant decrease in IFNAR1 and IFNAR2 expression, and a significant increase in MxA compared to non-treated patients and healthy controls. Also, those patients who had a good response to treatment had a significant decrease in IFNAR1 and IFNAR2 expression compared to non-responders, non-treated patients and healthy controls. IFNbeta influences the expression of its receptors, and is greater in patients who respond to IFNbeta treatment. This down-regulation could be indicative of the response to IFNbeta.

[Interferon-beta response in multiple sclerosis associated with pre-treatment disability]

AIM

To study pre-treatment clinical features and influence of neutralising antibodies (NABs) in clinical response to interferon-beta (IFNB).

PATIENTS AND METHODS

We analysed clinical characteristics and NABs to IFNB in 96 multiple sclerosis patients treated with IFNB. Clinical response was established by clinical criteria: = 1 relapse or an increase = 0.5 or 1 point in the Expanded Disability Status Scale (EDSS) score after one year of treatment compared with the year prior to IFNB therapy.

RESULTS

Baseline clinical characteristics were similar for responders and non-responders, except for a significantly higher baseline mean EDSS score in non-responders. Time-to-first-relapse was longer and the number of patients relapse-free was higher for NAB-negative patients, but we were unable to show an association with the disability status, probably due to sample size.

CONCLUSIONS

Response to IFNB was significantly associated with pre-treatment disability measured by the EDSS. The presence of NABs to IFNB presented a delayed negative effect for relapses.

HLA class II and response to interferon-beta in multiple sclerosis

OBJECTIVE

To study the relationship between human leucocyte antigen (HLA) genotype and clinical response to interferon-beta (IFN-beta).

METHODS

We analysed the HLA class II genotypes of 96 multiple sclerosis (MS) patients treated with IFN-beta. The patients were classified as responders or non-responders according to clinical criteria: one or more relapses or a sustained increase after 1 year treatment compared with the year prior to IFN-beta therapy of > or = 0.5 points on the Expanded Disability Status Scale (EDSS).

RESULTS

There were 66 (69%) responders and 30 (31%) non-responders. Baseline clinical characteristics were similar. We found no association between HLA class II alleles and clinical response to IFN-beta.

CONCLUSIONS

HLA genotype does not appear to influence the clinical response to IFN-beta in MS patients.

IFNAR1 and IFNAR2 polymorphisms confer susceptibility to multiple sclerosis but not to interferon-beta treatment response

We investigated the role of three polymorphisms in the IFNAR1 (SNPs 18417 and -408) and IFNAR2 (SNP 11876) genes in multiple sclerosis (MS) susceptibility and in the IFNbeta treatment response in a group of 147 patients and 210 controls undergoing interferon therapy during the last 2 years. Only the 18417 and the 11876 SNPs showed an association with disease susceptibility (p=0.001 and 0.035, respectively) although no differential genotype distribution were observed between interferon responders and non-responder MS patients. No alteration of the expression level of IFNAR-1 was observed with respect to the -408 genotypes or to interferon treatment response. These data suggest a role for the IFNAR pathway in susceptibility to MS.

DQB1*0602 allele shows a strong association with multiple sclerosis in patients in Malaga, Spain

BACKGROUND

The human leukocyte antigen (HLA) class II DR2 haplotype (DRB1*1501, DQA1*0102, DQB1*0602) has been associated with multiple sclerosis (MS) in all ethnic groups and very strongly in Caucasians.

AIM

To investigate the possible HLA class II (DRB1, DQA1 and DQB1) associations with MS in Malaga, southern Spain.

METHODS

We analysed the HLA class II sub-regions DRB1, DQA1 and DQB1 by polymerase chain reaction (PCR) and sequence-specific oligonucleotide probe hybridization (PCR/SSO) for DRB1 and DQB1 and with sequence-specific primers (PCR/SSP) for DRB1 subtypes and DQA1. Possible HLA class II associations with clinical MS characteristics were investigated in 149 subjects with and 160 without MS.

RESULTS

Associations were detected between MS and the HLA class II alleles DRB1*1501 (45.6 % vs. 21.3%, p=0.001), DQA1*0102 (44% vs. 29.4%, p=0.001) and DQB1*0602 (45% vs. 20.6%, p=0.001). The DR2 haplotype (DRB1*1501, DQA1*0102, DQB1*0602) was associated with MS (43.6 % vs. 20%, p=0.002). DQB1*0602 was the only allele that maintained an association with MS in a logistic regression model. No HLA class II alleles or genotypes were significantly associated with any clinical characteristics of MS.

CONCLUSIONS

Our results confirm the positive association of the DR2 haplotype with MS, particularly the allele DQB1*0602, in the population studied. DR4 was not associated with the disease in Malaga. HLA class II alleles or haplotypes were not associated with clinical or demographic characteristics, or clinical form or severity of MS.

Clinical benefits of interferon beta-1a in relapsing-remitting MS: a phase IV study

OBJECTIVE

To evaluate the efficacy and safety of IFNbeta-1a (Avonex, Biogen, Inc., Cambridge, MA, USA) in patients with relapsing-remitting multiple sclerosis (MS).

METHODS

In this multicenter, open-label, prospective clinical trial, 96 patients with relapsing-remitting MS received IFNbeta-1a 30 mcg intramuscularly once weekly for 2 years. Outcome variables included: change from baseline in mean number of exacerbations, proportion of exacerbation-free patients, and mean Expanded Disability Status Scale (EDSS) scores at Years 1 and 2.

RESULTS

IFNbeta-1a significantly (P < 0.0001) reduced exacerbation rate at Years 1 and 2 of treatment. The percentage of exacerbation-free patients was 53% during Year 1 and 33% during Year 2. Mean EDSS scores were 2.96 +/- 1.26 at baseline, 2.89 +/- 1.42 at Year 1, and 3.00 +/- 1.62 at Year 2 (P = 0.116). EDSS scores improved in 35.4%, remained stable in 28.1%, and worsened in 36.5% of patients. IFNbeta-1a treatment was well tolerated.

CONCLUSION

This study confirms and extends the beneficial clinical profile for IFNbeta-1a in relapsing MS.

Quality of life in multiple sclerosis patients in Spain

OBJECTIVE

The cross-sectional study evaluated the psychometric properties of the Functional Assessment of Multiple Sclerosis (FAMS) Spanish version and its use in measuring quality of life (QOL) of multiple sclerosis (MS) patients in Spain.

METHODS

The FAMS is a factorially derived self-report scale designed to assess six primary aspects of QOL of patients with MS: Mobility, Symptoms, Emotional Well-Being, General Contentment, Thinking and Fatigue, and Family/Social Well-Being. Its Spanish translated version was used to assess QOL of 625 MS patients recruited in an outpatient clinic setting from 58 hospitals in Spain. Internal consistency of the Spanish FAMS was evaluated Multiple regression analyses were performed to identify significant predictors from demographic, clinical and treatment characteristics, and Kurtzke Expanded Disability Status Scale (EDSS) scores in predicting FAMS scale scores.

RESULTS

Most of the patients are females (66%), and 74% were of the relapsing-remitting (RR) clinical subtype. Cronbach's alpha coefficients were high (range=0.78-0.96), indicating subscale homogeneity comparable to that of the original English version. Linear multivariate regression analyses revealed that the EDSS is a dominant variable in predicting all the FAMS subscales, especially mobility (R2=0.51) and the total scores.

CONCLUSIONS

The Spanish FAMS is a psychometrically valid instrument that allows clinicians and clinical researchers the ability to measure the QOL concerns of MS patients in Spain.

Combination therapy with interferon beta-1b and azathioprine in secondary progressive multiple sclerosis. A two-year pilot study

Combination therapy may benefit the subgroup of patients with secondary progressive multiple sclerosis (SPMS) who do not respond to interferon beta (IFNB). We performed a two-year study of azathioprine (AZA) combined with IFNB-1b in SPMS patients who had not responded well to IFNB-1b alone. Patients with SPMS were eligible for this non-controlled prospective study if they had two or more relapses requiring corticosteroid treatment or deteriorated by at least 0.5 points on the Expanded Disability Status Scale (EDSS) while on IFNB-1b in the year preceeding the study. Patients were to continue treatment with IFNB-1b (8 MIU qod, subcutaneous) and received AZA (50 mg tid, oral). Safety was assessed in terms of adverse reactions and laboratory measures graded according to the WHO toxicity scale. Efficacy was explored by changes in relapse rate, EDSS, 9-hole peg test (9-HPT), neuropsychological scores, and magnetic resonance imaging (MRI) results. Neutralizing antibodies (NAB) were measured. Ten SPMS patients (6 females) with a median EDSS score of 4.5 were enrolled. One patient withdrew because of gastrointestinal complaints, one was withdrawn owing to poor compliance, and 8 patients completed therapy. The only frequent side effect was lymphopenia, reported at least once in all patients. Annual relapse rate was reduced by approximately 50 % in the second year. There was a significant trend for EDSS increase. Total lesion load measured by MRI decreased at 12 and 24 months; only one patient had active lesions. No changes were seen in the 9-HPT. There was a significant improvement in neuropsychological tests after 24 months ( p = 0.045). One patient tested positive for NAB throughout the study, and transient NAB were detected in 4 patients. In conclusion, combination therapy with IFNB-1b and AZA was safe and generally well tolerated in patients with SPMS. Strict clinical and laboratory monitoring is recommended during this combination therapy.

Study of binding and neutralising antibodies to interferon-beta in two groups of relapsing-remitting multiple sclerosis patients

Interferon (IFN)-beta is generally considered an effective treatment for multiple sclerosis (MS); however, some patients do not respond to this therapy, possibly due to the production of neutralising antibodies (NAB) which can prevent the biological effect of IFN-beta. We compared the two types of IFN-beta, the glycosylated IFN-beta1a and the non-glycosylated IFN-beta1b, as their chemical differences may entail differing immunogenic capacities. We studied 22 relapsing-remitting MS patients treated with IFN-beta1a and 31 treated with IFN-beta1b for 1 year, using the same assay and criteria, to compare the two types of IFN-beta in their ability to induce binding and neutralising antibodies and examined the correlation of the findings with the clinical data. Binding antibodies to IFN-beta1a and IFN-beta1b were determined by enzyme-linked immunosorbent assay. A bioassay was used to detect and quantify the NABs to IFN-beta, measuring the capacity of NABs to block the antiviral resistance induced by IFNs. Binding antibodies were found in 32 % of those treated with IFN-beta1a and in 52 % of those treated with IFN-beta1b; NABs were found in 14% and 24 %, respectively. Both groups showed a significant decrease in relapse rate during the first year of treatment. These results demonstrate that the IFN-beta1b molecule is more immunogenic than the IFN-beta1a molecule. This may be due to the non-glycosylated, chemical structure of the former, which can produce aggregates and enhance antibody production. No association was found between the presence of NABs and the clinical status of the patients.

The prevalence of multiple sclerosis in the Sanitary District of Vélez-Málaga, southern Spain

Since little is known about the prevalence of multiple sclerosis (MS) in Spain, we undertook an epidemiologic study to ascertain the prevalence of MS in the Sanitary District of Vélez-Málaga, close to the city of Málaga, in southern Spain. The crude prevalence rate of MS in Vélez-Málaga was 53 per 100,000, twice as high as the prevalence previously reported in both the city and province of Málaga. The MS prevalence in the Sanitary District of Vélez-Málaga is similar to that in Sicily and in Cyprus.