BAFF Index and CXCL13 levels in the cerebrospinal fluid associate respectively with intrathecal IgG synthesis and cortical atrophy in multiple sclerosis at clinical onset.

BACKGROUND: B lymphocytes are thought to play a relevant role in multiple sclerosis (MS) pathology. The in vivo analysis of intrathecally produced B cell-related cytokines may help to clarify the mechanisms of B cell recruitment and immunoglobulin production within the central nervous system (CNS) in MS. METHODS: Paired cerebrospinal fluid (CSF) and serum specimens from 40 clinically isolated syndrome suggestive of MS or early-onset relapsing-remitting MS patients (CIS/eRRMS) and 17 healthy controls (HC) were analyzed for the intrathecal synthesis of IgG (quantitative formulae and IgG oligoclonal bands, IgGOB), CXCL13, BAFF, and IL-21. 3D-FLAIR, 3D-DIR, and 3D-T1 MRI sequences were applied to evaluate white matter (WM) and gray matter (GM) lesions and global cortical thickness (gCTh). RESULTS: Compared to HC, CIS/eRRMS having IgGOB (IgGOB+, 26 patients) had higher intrathecal IgG indexes (p < 0.01), lower values of BAFF Index (11.9 ± 6.1 vs 17.5 ± 5.2, p < 0.01), and higher CSF CXCL13 levels (27.7 ± 33.5 vs 0.9 ± 1.5, p < 0.005). In these patients, BAFF Index but not CSF CXCL13 levels inversely correlated with the intrathecal IgG synthesis (r > 0.5 and p < 0.05 for all correlations). CSF leukocyte counts were significantly higher in IgGOB+ compared to IgGOB- (p < 0.05) and HC (p < 0.01), and correlated to CSF CXCL13 concentrations (r 0.77, p < 0.001). The gCTh was significantly lower in patients with higher CSF CXCL13 levels (2.41 ± 0.1 vs 2.49 ± 0.1 mm, p < 0.05), while no difference in MRI parameters of WM and GM pathology was observed between IgGOB+ and IgGOB-. CONCLUSIONS: The intrathecal IgG synthesis inversely correlated with BAFF Index and showed no correlation with CSF CXCL13. These findings seem to indicate that intrathecally synthesized IgG are produced by long-term PCs that have entered the CNS from the peripheral blood, rather than produced by PCs developed in the meningeal follicle-like structures (FLS). In this study, CXCL13 identifies a subgroup of MS patients characterized by higher leukocyte counts in the CSF and early evidence of cortical thinning, further suggesting a role for this chemokine as a possible marker of disease severity.

Increased incidence of multiple sclerosis in the Veneto region, Italy.

BACKGROUND: To what extent the progressive increase in the incidence of multiple sclerosis (MS) observed in the province of Padova over the period 1970-1999 was an expression of a real increased risk of developing MS remained unclear. OBJECTIVE: The objective of this paper is to update the epidemiological figures of MS and probe whether the risk of having MS has increased in the province of Padova during the decade 2000-2009. METHODS: All patients born in Italy and having a diagnosis of MS or possible MS identified through analysis of all available sources of information were included in the study. The incidence and prevalence rates between 2000 and 2009 were obtained and compared with our previously published data. RESULTS: On 31 December 2009, the overall prevalence was 139.5/100,000, 192.0 ± 9.5 for females and 83.9 ± 6.3 for males. During the decade 2000-2009, the overall incidence rate of MS was 5.5 ± 0.5, 7.4 ± 0.8 for females and 3.5 ± 0.6 for males. The onset-diagnosis delay, the female/male ratio and the mean age at onset did not significantly change compared to the prior period of observation. CONCLUSION: Our findings support the hypothesis of a real increased risk of developing MS in the province of Padova. Moreover, the actual prevalence of 1.4/1000 makes our region a high-risk geographical area for MS. The role played by exogenous factors in determining susceptibility to MS needs to be thoroughly investigated.

BAFF is decreased in the cerebrospinal fluid of multiple sclerosis at clinical onset.

B-cells are thought to play a relevant role in multiple sclerosis (MS) pathology. BAFF (B cell activating factor of the TNF family) is a B-cell survival factor constitutively produced inside the CNS by astrocytes. We studied the intrathecal synthesis of BAFF in MS at clinical onset. Paired serum and cerebrospinal fluid (CSF) specimens from 40 clinically isolated syndromes (CIS) suggestive of MS or early relapse-onset MS (eRRMS) and from 18 healthy controls (HC) were analysed. Patients were classified based on the detection of oligoclonal IgG bands in the CSF (IgGOB+ and IgGOB-). BAFF was detected by highly sensitive ELISA and its ratio (CSF-BAFF/serum-BAFF, QBAFF) and Index (QBAFF/QAlb, BAFF-Index) were calculated. IgGOB+ presented lower CSF concentrations of BAFF compared to both HC and IgGOB- (p<0.05). BAFF Index was significantly lower in IgGOB+ compared to both HC and IgGOB- (p<0.01). A significant inverse correlation between QIgG and QBAFF (r: -0.4, p<0.05) and between BAFF index and IgGIF (r: -0.4, p<0.05) or IgG Index (r: -0.4, p=0.05) was found in IgGOB+. The decreased CSF levels of BAFF in IgGOB+ at clinical onset suggest the absorption of this factor by intrathecally recruited B cells since the early disease phases.

Further data on the microsatellite locus D12S67 in worldwide populations: an unusual distribution of D12S67 alleles in Native Americans.

We report the frequencies of alleles at the microsatellite locus D12S67 in 2 widely separated ethnic groups of the world: 2 populations from Sulawesi, an island in the Indonesian archipelago, and 5 Native American tribes of Colombia, South America. The allele frequencies in the Minihasans and Torajans of Sulawesi are similar to each other (but the modal class allele is different) and in general agreement with those reported in mainland Asian groups, but different from both Europeans and Chinese Han of Taiwan. The 5 Native American tribes (Arsario, Kogui, Ijka, Wayuu, and Coreguaje) display different allele frequencies from those seen in Sulawesi populations, in other groups from Europe and mainland Asia, and in Chinese Han of Taiwan. Native Americans exhibit a bimodal distribution of alleles, unlike other groups, with significant differences among the tribes. The Arsario and Kogui have no admixture with Europeans or Africans and are the most distinctive, while the Wayuu have the most admixture and show most similarity to other groups. The data suggest that nonadmixed Native Americans may be quite distinctive with respect to this marker. The most common allele varies across the 5 tribes, from 249 base pairs to 261 base pairs. All samples exhibit Hardy-Weinberg genotype proportions; heterozygosities are lowest in the 2 nonadmixed Native American tribes. Examination of all the available data indicates that some east Asian and southeast Asian groups are characterized by a high frequency of smaller sized D12S67 alleles, while other populations have a greater proportion of the larger sized alleles. The cumulative, though still highly restricted, population data on locus D12S67 demonstrate that it may be of considerable value in anthropological genetic studies of ethnic groups. Data are required on Native Americans outside Colombia before this marker can be used in admixture studies of this group.

Deletion polymorphism in the human COL1A2 gene: genetic evidence of a non-African population whose descendants spread to all continents.

We report the frequencies of a deletion polymorphism at the alpha 2 (1) collagen gene (COL1A2) and argue that this distribution has major implications for understanding the evolution of modern humans immediately after their exodus from sub-Saharan Africa as well as their subsequent spread to all continents. The high frequency of the deletion in non-African populations and its complete absence in sub-Saharan African groups suggest that the deletion event occurred just before or shortly after modern humans left Africa. The deletion probably arose shortly after the African exodus in a group whose descendants were among the ancestors of all contemporary populations, except for sub-Saharan Africans. This, of course, does not imply that there was a single migration out of Africa. The GM immunoglobulin haplotype GM*A,X G displays a similar distribution to that for the COL1A2 deletion, and these 2 polymorphisms suggest that the exodus from Africa may not have been a rapid dispersion to all other regions of the world. Instead, it may have involved a period of time for the savanna-derived gene pool to adapt to novel selective agents, such as bacteria, viruses, and/or environmental xenobiotics found in both animal and plant foods in their new environment. In this context these polymorphisms are indicators of the evolution that occurred before the diaspora of these populations to the current distribution of modern peoples.