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Biomedical subjects

L M Grimaldi

Publications and source records attributed to L M Grimaldi.

At least 37 records · Page 2Linked to original sources

Multiple sclerosis in children under 6 years of age.

OBJECTIVES: To characterize MS patients with the earliest onset of disease. BACKGROUND: MS-primarily a disease of young adulthood-begins in childhood in 3 to 5% of cases. However, onset before 10 years of age is considered exceptional. Accordingly, inclusion age at onset is generally between 10 and 59 years. METHODS: Information was obtained on patients with MS treated at our institution (n = 6) or from reports in Medline or bibliographies. Onset of disease was before 6 years of age, for a total of 49 patients (29 girls, 20 boys). RESULTS: All patients had clinically defined MS according to Poser's criteria; 22 were also laboratory supported. The female/male ratio (1.4) was lower than that usually recorded for adult onset MS (2.0) and that of MS with onset between 6 and 15 years (2.2 to 3.0). The group of patients (n = 5) with onset before 24 months of age showed the lowest ratio (0.6) and carried the most unfavorable prognosis. Among initial symptoms, ataxia was preponderant (61%). Optic nerve involvement became more frequent with age. Generalized or partial seizures occurred in 22% of cases. First inter-attack interval was less than 1 year in 63% of the cases. The yearly relapse rate ranged from 1.1 at disease onset to 0.2 after 9 years from disease onset. At follow-up (mean length 6.8 years), the disease was relapsing-remitting in 84% patients and the grade of recovery was complete in 64%. CONCLUSIONS: Definite MS can be consistently diagnosed by current criteria for adult onset MS in patients with the earliest onset of disease who show peculiar clinical features and natural history. These findings may suggest a reconsideration of current lower limits for MS diagnostic criteria.

Age of Onset↗

Apolipoprotein E and alpha-1-antichymotrypsin allele polymorphism in sporadic and familial Alzheimer's disease.

Alzheimer disease (AD) patients with both sporadic and familial forms of AD and non-demented controls were genotyped for common polymorphisms in the signal peptide for alpha-1-antichymotrypsin (ACT) gene and in two different regions of apolipoprotein E (APOE) gene. The ACT TT genotype was over-represented (P = 0.025) in patients with early onset of sporadic AD. In this patient's group ACT TT genotype conferred a significant crude odds ratio for the disease (OR = 2.09; 95% CI = 1.09-4.00, P = 0.025). After adjustment for the APOE epsilon4 and APOE -491 genotypes, logistic regression analysis confirmed that the ACT TT genotype resulted independently associated with early onset AD (adjusted OR = 2.56; 85% CI = 1.3-5.2, P = 0.009). The frequency of APOE epsilon4 allele was increased in AD, as expected (OR = 5.92, 95% CI = 3.60-9.70, P = 0.0001). On the contrary, the APOE -491 A/T genotypes were not associated with AD. No preferential association of the APOE epsilon4 allele or APOE -491 A/T genotypes with ACT A/T alleles was observed in AD. Present findings indicated that subjects with ACT TT genotype had an increased risk of developing AD and suggested that this genotype influenced the risk of an early onset of the disease by affecting the production of ACT molecules.

Aged↗

Genetic heterogeneity in Italian families with familial hemiplegic migraine.

OBJECTIVE: To verify linkage to chromosome 19p13, to detect mutations in the CACNA1A gene, and to correlate genetic results to their clinical phenotypes in Italian families with familial hemiplegic migraine (FHM). BACKGROUND: FHM is an autosomal dominant disease, classified as a subtype of migraine with aura. Only a proportion of FHM patients have been associated with chromosome 19p13. Among these, four missense mutations within the CACNA1A gene in five unrelated families have been described. METHODS: A linkage study was performed in 19 patients affected by FHM from five families by studying microsatellite markers associated with the 19p13 region. All familial and seven additional sporadic patients with FHM were analyzed to search for mutations within the CACNA1A gene by applying the double gradient-denaturant gradient electrophoresis technique. RESULTS: Lod score values did not establish significantly linkage to chromosome 19. However, seven new genetic variants were detected: six were new polymorphisms. The seventh was a missense mutation present in family 1, and it was associated with a hemiplegic migraine phenotype without unconsciousness and cerebellar ataxia. Because this missense mutation is absent in the general population and cosegregates with the disease, it may be a pathologic mutation. CONCLUSIONS: Genetic heterogeneity of FHM has been shown in familial and sporadic FHM patients of Italian origin. The new missense mutation-G4644T-is associated with milder clinical features compared with typical FHM.

Adolescent↗

Relevance of interleukin 1 receptor antagonist intron 2 polymorphism in Italian MS patients.

The A1/A1 genotype of the anti-inflammatory cytokine interleukin 1 receptor antagonist (IL-1Ra) polymorphism was more frequent in 339 Italian MS patients than in healthy controls (HCs) (odds ratio = 1.83). A more aggressive disease course was also associated with A1+ genotypes and might reflect the reduced ability of mononuclear cell cultures of A1+ HCs to produce IL-1Ra. We conclude that an IL-1Ra gene polymorphism is associated with occurrence of disease and clinical course variability in Italian MS patients.

Adult↗

Analysis of an IFN-gamma gene (IFNG) polymorphism in multiple sclerosis in Europe: effect of population structure on association with disease.

An intronic dinucleotide polymorphism in the IFN-gamma gene (IFNG) was used as a marker for testing association with multiple sclerosis (MS). Disease association was analyzed in case-control sets sampled from four geographically separate European populations (Germany, Northern Italy, Sardinia, and Sweden). Only in the Swedish was a weak disease association of the IFNG allele pattern found, mainly due to a higher frequency of IFNG allele I1 in MS patients. No evidence for association was found in the German or Northern Italian populations. These results contrast with the situation in Sardinia. We have recently reported transmission disequilibrium of IFNG allele I2 in Sardinian MS siblings not carrying the predisposing DRB1 *03 or *04 alleles (Ann. Neurol. 44, 841-842, 1998). Further analysis now shows that I2 is significantly more often transmitted to DRB1 *03-/*04- males, than to DRB1 *03-/*04- females. The odds ratio (OR) for IFNG-associated susceptibility to MS in the total Sardinian DRB1*03-/*04- group was 1.88 for I2 heterozygotes but amounted to 8.235 for I2 homozygotes, suggestive of a recessive mode of inheritance. Score test-based statistics pointed to an I2 allele dosage effect acting in susceptibility. Comparison of the IFNG allele frequencies in seven European populations (Northern Finnish, Southern Finnish, Swedish, Danish, German, Italian, and Sardinian) revealed a highly different distribution pattern. We introduced latitude as a score variable in order to test for trend in binomial proportions. This test statistic showed that for both most common alleles, I1 and I2 (compiled allele frequency about 85%), a significant opposite north-to-south trend is seen throughout Europe. This effect is primarily due to the extreme values found in the outlier populations of Finland and Sardinia. Our findings are discussed with respect to recent literature pertinent to the role of the IFNG chromosome region in autoimmune diseases.

Alleles↗

Peripheral levels of caspase-1 mRNA correlate with disease activity in patients with multiple sclerosis; a preliminary study.

The cysteine protease caspase-1 plays a crucial part in the inflammatory process due to its ability to proteolitically activate proinflammatory cytokine precursors, such as interleukin (IL)-1beta and IL-18. Multiple sclerosis is a chronic inflammatory demyelinating disease of the CNS in which the pathogenic process is mainly orchestrated by proinflammatory cytokines. The role of caspase-1 in multiple sclerosis was evaluated by measuring its mRNA levels in peripheral blood mononuclear cells (PBMCs) from seven patients with relapsing-remitting multiple sclerosis every 15 days over a 1 year period. The recorded levels were compared with clinical and MRI evidence of disease activity. Brain MRI was performed monthly in each patient. Caspase-1 mRNA levels were significantly increased in PBMCs from patients with multiple sclerosis compared with healthy controls (p<0.001). In patients with multiple sclerosis, a twofold to threefold increase of caspase-1 mRNA mean level was found in the week preceding an acute attack (p<0. 05). The magnitude of caspase-1 mRNA increase correlated with the number of new (p=0.01) but not persisting gadolinium enhancing brain MRI lesions. In conclusion, caspase-1 might be involved in the immune mediated process underlying CNS inflammation and might represent a suitable peripheral immunological marker of disease activity in multiple sclerosis.

Adult↗

Central nervous system delivery of interleukin 4 by a nonreplicative herpes simplex type 1 viral vector ameliorates autoimmune demyelination.

Multiple sclerosis (MS) is a T cell-mediated organ-specific inflammatory disease leading to central nervous system (CNS) demyelination. On the basis of results obtained in experimental autoimmune encephalomyelitis (EAE) models, MS treatment by administration of antiinflammatory cytokines such as interleukin 4 (IL-4) is promising but is hampered by the limited access of the cytokines to the CNS and by the pleiotropic effects of systemically administered cytokines. We established a cytokine delivery system within the CNS using non-replicative herpes simplex type 1 (HSV-1) viral vectors engineered with cytokine genes. These vectors injected into the cisterna magna (i.c.) of mice diffuse in all ventricular and subarachnoid spaces and infect with high efficiency the ependymal and leptomeningeal cell layers surrounding these areas, without obvious toxic effects. Heterologous genes contained in the vectors are efficiently transcribed in infected ependymal cells, leading to the production of high amounts of the coded proteins. For example, 4.5 ng of interferon gamma (IFN-gamma) per milliliter is secreted into the cerebrospinal fluid (CSF) up to day 28 postinjection (p.i.) and reaches the CNS parenchyma in bioactive form, as demonstrated by upregulation of MHC class I expression on CNS-resident cells. We then exploited the therapeutic potential of the vectors in EAE mice. An HSV-1-derived vector containing the IL-4 gene was injected i.c. in Biozzi AB/H mice at the time of EAE induction. We found the following in treated mice: (1) delayed EAE onset, (2) a significant decrease in clinical score, (3) a significant decrease in perivascular inflammatory infiltrates and in the number of macrophages infiltrating the CNS parenchyma and the submeningeal spaces, and (4) a reduction in demyelinated areas and axonal loss. Peripheral T cells from IL-4-treated mice were not affected either in their antigen-specific proliferative response or in cytokine secretion pattern. Our results indicate that CNS cytokine delivery with HSV-1 vectors is feasible and might represent an approach for the treatment of demyelinating diseases. Advantages of this approach over systemic cytokine administration are the high cytokine level reached in the CNS, the absence of effects on the peripheral immune system, and the long-lasting cytokine production in the CNS after a single vector administration.

Animals↗

IL-12 is involved in the induction of experimental autoimmune myasthenia gravis, an antibody-mediated disease.

IL-12 has been shown to be involved in the pathogenesis of Th1-mediated autoimmune diseases, but its role in antibody-mediated autoimmune pathologies is still unclear. We investigated the effects of exogenous and endogenous IL-12 in experimental autoimmune myasthenia gravis (EAMG). EAMG is an animal model for myasthenia gravis, a T cell-dependent, autoantibody-mediated disorder of neuromuscular transmission caused by antibodies to the muscle nicotinic acetylcholine receptor (AChR). Administration of IL-12 with Torpedo AChR (ToAChR) to C57BL/6 (B6) mice resulted in increased ToAChR-specific IFN-gamma production and increased anti-ToAChR IgG2a serum antibodies compared with B6 mice primed with ToAChR alone. These changes were associated with earlier and greater neurophysiological evidence of EAMG in the IL-12-treated mice, and reduced numbers of AChR. By contrast, when IL-12-deficient mice were immunized with ToAChR, ToAChR-specific Th1 cells and anti-ToAChR IgG2a serum antibodies were reduced compared to ToAChR-primed normal B6 mice, and the IL-12-deficient mice showed almost no neurophysiological evidence of EAMG and less reduction in AChR. These results indicate an important role of IL-12 in the induction of an antibody-mediated autoimmune disease, suggest that Th1-dependent complement-fixing IgG2a anti-AChR antibodies are involved in the pathogenesis of EAMG, and help to account for the lack of correlation between anti-AChR levels and clinical disease seen in many earlier studies.

Animals↗

Proinflammatory cytokines regulate antigen-independent T-cell activation by two separate calcium-signaling pathways in multiple sclerosis patients.

Central nervous system (CNS) lesions typical of multiple sclerosis (MS) are characterized by demyelinating inflammatory infiltrates that contain few CNS antigen-specific autoreactive T cells and a multitude of pathogenic non-antigen-specific mononuclear cells. Here, we report that in patients with MS the combined action of interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNFalpha), interleukin (IL)-2, and IL-6 leads to the activation of most peripheral T cells (mainly CD4 memory) by promoting a persistent intracellular calcium increase via two independent signaling pathways. The activation of these pathways, one activated by IFNgamma and the other by the combination TNFalpha/IL-2/IL-6, is independent from myelin antigens and precedes by 2 weeks phases of disease activity (eg, clinical relapses and/or appearance of gadolinium-enhancing lesions on brain magnetic resonance imaging scans during 1 year of follow-up). Our results indicate that an appropriate combination of the four cytokines, three with a proinflammatory profile and one necessary for T-cell growth and differentiation, can activate in an antigen-independent fashion most peripheral T cells from MS patients. This mechanism is likely to contribute to the recruitment of nonspecific lymphocytes into the cellular activation processes leading to CNS demyelination and may represent a major target for immune intervention in MS.

Antigens↗

Identification of peptides binding to IgG in the CSF of multiple sclerosis patients.

Phage displayed random peptide libraries were screened in order to identify phagotopes reacting with the IgG present in the cerebrospinal fluid (CSF) of multiple sclerosis (MS) patients. Six families of phagotopes each composed of different isolates were identified. These phagotopes were used as reagents, to characterise IgG present in the CSF of MS patients. The following results were obtained: (a) CSF antibodies from different patients display different specificities; (b) anti-phagotope antibodies are also present in the serum of MS patients; (c) Anti-phagotope antibodies are equally frequent in the serum of MS patients and of healthy individuals; (d) some of the anti-phagotope antibodies are enriched in the CSF of MS patients. These data show that the natural antigen(s) recognised by CSF antibodies is rather common in the general population. By using the selected phagotopes as immunogens in rabbits, we have derived large quantities of anti-phagotope antisera which can provide for useful tools toward the identification of the natural antigen(s) recognised by MS CSF antibodies.

Adult↗

CSF-enriched antibodies do not share specificities among MS patients.

The specificity of the oligoclonal immunoglobulins found in MS CSF is unknown. We have previously shown that random peptide libraries displayed on phage can be used to identify specific ligands for CSF antibodies. Here we describe the use of this tool in the attempt to identify MS-specific CSF-enriched antibody reactivities with potential pathogenic, diagnostic or prognostic value. Applying different experimental strategies, several ligands reacting with CSF-enriched antibodies were identified. When tested against a panel of 55 MS patients, none of the ligands found were recognized by antibodies shared by any two patients. We used the selected peptides to demonstrate the stability in time of CSF-enriched antibodies notwithstanding disease progression.

Adult↗

A gene therapy approach to treat demyelinating diseases using non-replicative herpetic vectors engineered to produce cytokines.

A successful gene therapy approach in organ-specific autoimmune diseases, such as multiple sclerosis (MS), encompasses the inhibition of the autoreactive T cells or the modification of the target organ cells by the introduction of exogenous 'protective' genes. In MS, an autoimmune disease of the central nervous system (CNS), the inciting autoantigen is still unknown and therefore the isolation of autoreactive T cells may only be inferential. At present, gene therapy approaches in MS should therefore aim to the modification of the target organ. Possible candidate genes to be transferred within the CNS of MS patients are those coding for anti-inflammatory cytokines (i.e. interleukin-4, interleukin-10, transforming growth factor beta) which have been shown to ameliorate demyelinating diseases at least in experimental models. However, a limiting factor for this therapy is the difficulty to reach the CNS. A gene therapy approach using viral vectors able to infect post-mitotic cells, such as those present within the CNS, without inducing toxic reactions, may overcome this limitation. We propose to use non-replicative herpetic vectors, which represent a viable gene-transfer alternative to the classical retroviral and adenoviral vectors. Key advantages are their size, able to accommodate multiple foreign genes, and their ability to infect post-mitotic cells such as those present within the CNS. We first transferred a gene coding for interleukin-4 within the CNS of mice undergoing experimental allergic encephalomyelitis, an animal model for MS, using non-replicative Herpes Simplex Virus type 1-derived vectors. We found that this approach ameliorates the disease course and delays the disease onset. The establishment of this technique to deliver anti-inflammatory cytokines within the CNS using herpetic vectors should clarify the role of individual cytokines in the demyelinating process and allow assessment of whether gene therapy using herpetic vectors is a feasible and safe approach to treat human demyelinating disorders.

Animals↗

Tumor necrosis factor alpha and its receptors in relapsing-remitting multiple sclerosis.

In the attempt to further characterize the extent and timing of tumor necrosis factor (TNF)alpha-system activation during multiple sclerosis (MS), we performed a cross-sectional and a longitudinal study in a total of 73 relapsing-remitting MS patients. We assessed serum levels of soluble TNFalpha, soluble TNFalpha receptor 1 (R1) and soluble TNFalpha receptor 2 (R2) in 65 relapsing-remitting MS patients in different phases of disease. TNFalpha, R1 and R2 serum levels measured in MS patients did not differ from those measured in healthy individuals and did not correlate with (a) clinical relapses, (b) presence of gadolinium-enhancing brain-magnetic resonance imaging (MRI) lesions, and (c) bioactivity of TNFalpha. We also measured in 8 additional relapsing-remitting MS patients peripheral blood mononuclear cells (PBMC) mRNA levels of TNFalpha, R1 and R2 every 15 days for one year. In 4 of these patients we also measured levels of soluble TNFalpha, R1 and R2 every 15 days for 5 months across a clinical exacerbation. PBMC TNFalpha, R1 and R2 mRNA levels and serum levels of soluble R1 and R2, but not TNFalpha, fluctuated concordantly (P<0.05) and peaked a mean of 6 weeks before clinical and MRI evidence of disease activity. Moreover, we found a significant positive correlation between cumulative TNFalpha and R2 mRNA levels (measured during the follow-up period in the 8 MS patients studied serially) and the number of clinical attacks recorded in these patients during the study. Our data show that serum levels of soluble TNFalpha, R1, and R2 in MS patients do not differ from those of healthy individuals. However, although within normal values, the transcription and production rate of all these molecules fluctuate concordantly in the peripheral blood during the course of the disease (with the exception of soluble TNFalpha) and their maximal elevation significantly precedes the occurrence of clinical exacerbations. It is not clear whether soluble TNFalpha escapes recognition by commonly used assays or is simply not released in its soluble form in MS patients. In any case, measurement of TNFalpha mRNA levels and R1 and R2 mRNA and protein levels appears to be a better indicator of disease fluctuations during the course of MS than assessments of soluble TNFalpha protein.

Adult↗

Occurrence and clinical relevance of an interleukin-4 gene polymorphism in patients with multiple sclerosis.

An epistatic gene interaction has been advocated to explain disease susceptibility in multiple sclerosis (MS). Cytokine genes are possible candidates due to the central role played by cytokines in the regulation of the immune-mediated pathogenetic process leading to central nervous system demyelination in these patients. Since interleukin (IL)-4 gene polymorphisms have been associated with immune-mediated diseases, we have analysed the relationship between a variable number of tandem repeat polymorphism of the IL-4 gene and clinical and physiological features of 256 sporadic MS patients and 146 healthy controls. Genotype frequencies were similar between the MS group and healthy controls. However, in MS patients a positive and significant correlation (r = 0.91; p < 0.001) was found between the carriage rate of the IL-4 B1 allele (from 0.21 to 0.36) and age of disease onset. No association was found between IL-4 alleles and disease progression, sex or ethnic background of the patients. Our results show that the IL-4 B1 allele is associated with late onset of MS and therefore might represent a modifier of age of onset rather than a susceptibility factor for patients with MS.

Adult↗

Antibodies to 125I-glutamic acid decarboxylase in patients with stiff man syndrome.

Antibodies to glutamic acid decarboxylase (GAD) are found in about 40% of patients with stiff man syndrome. A new assay involving immunoprecipitation of (125)I-glutamic acid decarboxylase was used to measure anti-GAD antibodies in 18 patients with stiff man syndrome. Of the eight serum samples from patients with stiff man syndrome, that had previously been found positive by immunoprecipitation of (35)S-GAD, seven were strongly positive with (125)I-GAD and one gave an equivocal result. Other serum samples from patients with stiff man syndrome and from controls were negative except one from a patient who had a thymoma, acquired neuromyotonia, and myasthenia gravis. Nine of 35 serum samples referred for testing were positive; in two of these the serum titre was 20-50 times higher than that in the CSF. This assay should prove useful in the diagnosis, management, and investigation of stiff man syndrome.

Antibodies↗

Interferon-gamma induced increases in intracellular calcium in T lymphocytes from patients with multiple sclerosis precede clinical exacerbations and detection of active lesions on MRI.

BACKGROUND: Interferon (IFN)-gamma exerts a multiplicity of actions potentially relevant for the pathogenesis of multiple sclerosis, including the expression of a transplasmalemma calcium (Ca2+) influx leading to an intracellular Ca2+ ([Ca2+]i) increase able to lower T lymphocyte threshold of excitability. It has been previously shown in a cross sectional cumulative study that this influx is associated with clinical and MRI evidence of disease activity. METHODS: To evaluate the temporal relation between disease activity and the IFN-gamma activated Ca2+ influx in individual patients, a fluorimetric analysis was performed on peripheral blood lymphocytes from eight patients with relapsing-remitting multiple sclerosis every 15 days for one year. RESULTS: Fluctuations of the influx were correlated with clinical events and monthly enhanced brain MRI. The influx was detected a mean of 10.4 (range 7-17) times per patient during our analysis. In 61% of the occasions, influx induced [Ca2+]i increases were recorded in each patient in more than two consecutive measurements, determining sustained [Ca2+]i increases lasting for a mean of 31.5 days. Peak [Ca2+]i increases preceded clinical attacks (P=0.04) or maximal detection of brain MRI enhancing lesions (P=0.05) by a mean of 30.8 and 34.2 days respectively. Spectral analysis of time series further indicated that the fluctuation frequency of [Ca2+]i increases due to the influx over time were superimposable on the appearance of new MRI lesions in all patients and confirmed that in two thirds of the patients these [Ca2+]i increases occurred significantly before (P<0.005) or concurred with new lesion appearance. Finally, the overall presence of the influx throughout the follow up period correlated (P=0.03) with the patients' exacerbation rates. CONCLUSIONS: Intracellular events leading to T lymphocyte activation in multiple sclerosis occur in the peripheral blood before CNS specific events become evident and are, in part, sustained by cytokine induced Ca2+ mediated phenomena.

Adult↗