Diagnostics of dysimmune peripheral neuropathies.

This document presents the guidelines for anti-ganglioside antibody testing that have been developed following a consensus process built on questionnaire-based surveys, internet contacts, and discussions at workshops of the sponsoring Italian Association of Neuroimmunology (AINI) congresses. Main clinical information on dysimmune peripheral neuropathies, indications and limits of anti-ganglioside antibody testing, instructions for result interpretation, and an agreed laboratory protocol (Appendix) are reported for the communicative community of neurologists and clinical pathologists.

Relationship between CSF tau biomarkers and structural brain MRI measures in frontotemporal lobar degeneration.

BACKGROUND: Recently in the field neurodegenerative diseases increasing attention has been pointed to CSF biomarkers and their integration with neuroimaging (1). Frontotemporal lobar degeneration (FTLD) refers to a heterogeneous group of clinical syndromes with different underlying proteinopathies including tau pathology. CSF biomarkers have been proposed as diagnostic and prognostic factors. Aim of our study was to evaluate the relationship between CSF tau biomarkers and structural MRI brain measures in FTLD. METHODS: We included early FTLD patient. All included patients underwent lumbar puncture to evaluate amyloid, total-tau (t-tau), phospho-tau 181 (p-tau); p-tau/t-tau ratio was also calculated; brain MRI was performed to estimate whole brain volume, volume of principal deep grey matter structures and regional cortical thickness. RESULTS: Demographic characteristics of the 28 included patients were as follows: female/male: 9/19; mean ± SD age: 68.1 ± 7.8 years. The p-tau/t-tau ratio was significantly correlated with whole brain volume (r = 0.69; p: 0.001), left putamen volume (r = 0.55 p: 0.009), left pallidum volume (r = 0.41; p: 0.01), right accumbens area (r = 0.47; p: 0.02). P-tau/t tau ratio showed also a significant correlation with cortical thickness of left temporal lobe (r = 0.74; p: 0.001) and right lateral orbital frontal cortex (r = 0.45; p: 0.03). Linear regression showed a significant relationship between p-tau/t-tau ratio and left temporal pole (p = 0.01; r2: 0.60) and brain volume (p:0.002; r2: 0.56) after controlling for age and gender. CONCLUSIONS: Our data suggest that CSF biomarkers, especially p-tau/t-tau ratio, could play a role as prognostic factor in FTLD. Further longitudinal investigations are needed to confirm these findings.

PTPRC (CD45) C77G mutation does not contribute to multiple sclerosis susceptibility in Sardinian patients.

A linkage and association of the CD45 (protein-tyrosine phosphatase, receptor-type C) C77G polymorphism and multiple sclerosis (MS) has been found in some studies but not in others. We analysed the C77G polymorphism in MS patients from the genetically homogeneous population of Sardinia. Using the transmission disequilibrium test, the mutation has been sought in 241 patients and 217 healthy sibs (HS) from singleton MS families and it was found in 5 (2.07 %) affected and 3 (1.38%) HS from 7 heterozygous parents (1.45 %). Transmission of the G77 allele was 71.4 % (TDT = 1.3, P = 0.26) in patients and 50% (TDT = 0, P = 1) in HS. Stratifying families according to carriage of MS-predisposing (DR+) or not-predisposing (DR-) HLA-DR-DQ genotype in patients, percentage of G77 transmission to DR+ patients was 33 (TDT = 0.33, P = 0.56, Pc = 1.12), while it was 100 (TDT = 4, P = 0.045, Pc = 0.09) in the DR-patients. We concluded that, despite the presence of CD45 G77 polymorphism in a few patients who did not carry the HLADR- DQ MS-predisposing molecules, CD45 did not contribute to development of the disease in Sardinian MS.

Interaction between HLA-DRB1-DQB1 haplotypes in Sardinian multiple sclerosis population.

We performed a case-control study in 2,555 multiple sclerosis (MS) Sardinian patients and 1,365 healthy ethnically matched controls, analyzing the interactions between HLA-DRB1-DQB1 haplotypes and defining a rank of genotypes conferring a variable degree of risk to the disease. Four haplotypes were found to confer susceptibility (*13:03-*03:01 OR = 3.3, Pc 5.1 × 10(-5), *04:05-*03:01 OR = 2.1, Pc 9.7 × 10(-8), *15:01-*06:02 OR = 2.0, Pc = 9.1 × 10(-3), *03:01-*02:01 OR = 1.7 Pc = 7.9 × 10(-22)) and protection (*11, OR = 0.8, Pc = 2.7 × 10(-2), *16:01-*05:02 OR = 0.6, Pc = 4.8 × 10(-16), *14:01-4-*05:031 = OR = 0.5, Pc = 9.8 × 10(-4) and *15:02-*06:01 OR = 0.4, Pc = 5.1 × 10(-4)). The relative predispositional effect method confirms all the positively associated haplotypes and showed that also *08 and *04 haplotypes confers susceptibility, while the *11 was excluded as protective haplotype. Genotypic ORs highlighted two typologies of interaction between haplotypes: i) a neutral interaction, in which the global risk is coherent with the sum of the single haplotype risks; ii) a negative interaction, in which the genotypic OR observed is lower than the sum of the OR of the two haplotypes. The phylogenic tree of the MS-associated DRB1 alleles found in Sardinian patients revealed a cluster represented by *14:01, *04:05, *13∶03, *08:01 and *03:01 alleles. Sequence alignment analysis showed that amino acids near pocket P4 and pocket P9 differentiated protective from predisposing alleles under investigation. Furthermore, molecular dynamics simulation performed on alleles revealed that position 70 is crucial in binding of MBP 85-99 peptide. All together, these data suggest that propensity to MS observed in Sardinian population carried by the various HLA-DRB1-DQB1 molecules can be due to functional peculiarity in the antigen presentation mechanisms.