Genetic continuity and change among the Indigenous peoples of California.

Before the colonial period, California harboured more language variation than all of Europe, and linguistic and archaeological analyses have led to many hypotheses to explain this diversity1. We report genome-wide data from 79 ancient individuals from California and 40 ancient individuals from Northern Mexico dating to 7,400-200 years before present (BP). Our analyses document long-term genetic continuity between people living on the Northern Channel Islands of California and the adjacent Santa Barbara mainland coast from 7,400 years BP to modern Chumash groups represented by individuals who lived around 200 years BP. The distinctive genetic lineages that characterize present-day and ancient people from Northwest Mexico increased in frequency in Southern and Central California by 5,200 years BP, providing evidence for northward migrations that are candidates for spreading Uto-Aztecan languages before the dispersal of maize agriculture from Mexico2-4. Individuals from Baja California share more alleles with the earliest individual from Central California in the dataset than with later individuals from Central California, potentially reflecting an earlier linguistic substrate, whose impact on local ancestry was diluted by later migrations from inland regions1,5. After 1,600 years BP, ancient individuals from the Channel Islands lived in communities with effective sizes similar to those in pre-agricultural Caribbean and Patagonia, and smaller than those on the California mainland and in sampled regions of Mexico.

Assessment of anti-malondialdehyde-acetaldehyde antibody frequencies in rheumatoid arthritis with new data from two independent cohorts, meta-analysis, and meta-regression.

BACKGROUND: Autoantibodies are critical elements in RA pathogenesis and clinical assessment. The anti-malondialdehyde-acetaldehyde (anti-MAA) antibodies are potentially useful because of their claimed high sensitivity for all RA patients, including those lacking RF and anti-CCP antibodies. Therefore, we aimed to replicate these findings. METHODS: We independently attempted replication in Santiago and Barcelona using sera from 517 and 178 RA patients and 272 and 120 healthy controls, respectively. ELISA protocols for anti-MAA antibodies included five antigens (human serum albumin in three formulations, fibrinogen, and a synthetic peptide) and assays for the IgG, IgM, and IgA isotypes. We integrated our results with information found by searching the Web of Science for reports of anti-MAA antibodies in RA. The available patients (4989 in 11 sets) were included in a meta-analysis aimed at heterogeneity between studies. Factors accounting for heterogeneity were assessed with meta-regression. RESULTS: The sensitivity of anti-MAA antibodies in our RA patients was low, even in seropositive patients, with the percentage of positives below 23% for all ELISA conditions. Our results and bibliographic research showed IgG anti-MAA positive patients ranging from 6 to 92%. The extreme between-studies heterogeneity could be explained (up to 43%) in univariate analysis by sex, African ethnicity, the site of study, or recruitment from the military. The best model, including African ancestry and smoking, explained a high heterogeneity fraction (74%). CONCLUSION: Anti-MAA antibody sensitivity is extremely variable between RA patient collections. A substantial fraction of this variability cannot be attributed to ELISA protocols. On the contrary, heterogeneity is determined by complex factors that include African ethnicity, smoking, and sex.

Peptides Bearing Multiple Post-Translational Modifications as Antigenic Targets for Severe Rheumatoid Arthritis Patients.

Rheumatoid arthritis (RA) is characterized by the presence of autoantibodies that are of paramount importance for the diagnosis and prognosis of the disease and have been implicated in its pathogenesis. Proteins resulting from post-translational modifications (PTMs) are capable of triggering autoimmune responses important for the development of RA. In this work, we investigate serum antibody reactivity in patients with an established RA against a panel of chimeric peptides derived from fibrin and filaggrin proteins and bearing from one to three PTMs (citrullination, carbamylation and acetylation) by home-designed ELISA tests (anti-AMPA autoantibodies). The role of anti-AMPAs as biomarkers linked to the presence of a more severe RA phenotype (erosive disease with radiological structural damage) and to the presence of interstitial lung disease (ILD), a severe extra-articular manifestation in RA patients entailing a high mortality, was also analyzed. In general, the association with the clinical phenotype of RA was confirmed with the different autoantibodies, and especially for IgA and IgM isotypes. The prevalence of severe joint damage was only statistically significant for the IgG isotype when working with the peptide bearing three PTMs. Furthermore, the median titers were significantly higher in patients with RA-ILD, a finding not observed for the IgG isotype when working with the single- and double-modified peptides.

Strengths of Latinas in Spain: A Challenge for a Resilient Social Work Practice.

This article aims to break with two social stereotypes often held about Latinas in Spain. Authors analyze Latinas' main strengths from a resilient and intersectional approach, to consider them holistically within social work interventions. Rather than focusing on Latinas' difficulties, authors point to their multiple strengths and the ability to move forward. The study took place in the province of Tarragona, Catalonia (Spain). A qualitative approach was used. Participants included Latinas living in Tarragona and social workers from the Tarragona social services. The techniques used were nine life stories and 59 semi-open questionnaires with Latinas, and 14 interviews with social workers. The authors identified a fighting attitude and an entrepreneurial and creative spirit as both individual and collective strengths, especially within Latinas' social networks. Latinas did not recognize themselves as victims, nor did they claim to assume that identity. The social workers' interventions are implemented in a weak welfare system based on a model characterized by a paternalistic and victim-based viewpoint. Adopting approaches such as intersectionality and resilience would allow for the creation of fairer policies, programs, and projects targeted for Latinas, not just in Spain, but in other countries, too.

Anti-carbamylated protein antibody isotype pattern differs between palindromic rheumatism and rheumatoid arthritis.

BACKGROUND: A restricted response against citrullinated peptides/proteins, with less isotype usage, has been found in palindromic rheumatism (PR) in comparison with rheumatoid arthritis (RA). We hypothesized that this different antibody response may be observed for other post-translational modified proteins. We compared the prevalence and isotype usage of two specificities of anti-carbamylated peptide/protein antibodies (Anti-CarP) in patients with PR and RA. METHODS: Cross-sectional study including 54 patients with pure PR and 53 patients with RA, matched by sex, age, disease duration and ACPA. Anti-CarP specificities were determined by home-made enzyme-linked immunosorbent assay tests using a synthetic chimeric fibrin/filaggrin homocitrullinated peptide (CFFHP) and fetal calf serum (FCS) homocitrullinated protein as antigens. IgG, IgA and IgM isotypes were measured. RESULTS: Anti-CarP were positive (CFFHP or FCS) in 24% and 64% of patients with PR and RA, respectively (p < 0.005). All Anti-CarP isotype proportions were significantly lower in PR than in RA: Anti-CarP-IgG (24% versus 51%), Anti-CarP-IgA (7% versus 34%) and Anti-CarP-IgM (7% versus 36%). Mean titers of Anti-CarP isotypes were also lower in PR. In Anti-CarP positive patients, the isotype distribution differed between PR and RA: IgG Anti-CarP was used in all PR patients and in 79% of RA patients. By contrast, a significantly lower isotype usage of both IgA (31% versus 53%) and IgM (31% versus 56%) was observed in PR patients. No significant differences in clinical or demographic characteristics were observed according to Anti-CarP status in PR patients, except for a higher prevalence of ACPA and higher mean titers of ACPA and rheumatoid factor in Anti-CarP positive patients. CONCLUSION: Anti-CarP are found in patients with PR but in a lower proportion and with a different isotype usage from in RA, suggesting a distinct B cell response to homocitrullinated antigens in PR.

Development of a multiplex assay based on chimeric citrullinated peptides as proof of concept for diagnosis of rheumatoid arthritis.

Anti-citrullinated peptide/protein antibodies (ACPAs) are the most specific serological biomarkers for rheumatoid arthritis (RA). They have both diagnostic and prognostic value, and are related to more aggressive joint disease in RA. However, a single biomarker cannot differentiate RA subtypes. So, simultaneous analysis of target citrullinated peptides, using a multiplex array based on chimeric peptides composed of several domains of human proteins, could be useful. In this work, eight chimeric peptides and the corresponding native arginine-containing control peptides were obtained by solid-phase peptide synthesis. The study included RA and psoriatic arthritis (PsA) patients attending the Rheumatology Unit of the Hospital Clinic in Barcelona, as well as healthy blood donors (BD) at the same hospital. Our main aim was to explore the diagnostic value of the novel multiplex array compared to a commercial ELISA-based ACPA assay in a serum-saving way. Using the combination of the eight chimeric peptide antigens in the multiplex array, 61.4% of the RA cohort were positive for 3 or more peptides; while, the healthy BD and PsA cohorts did not show any reactivity with the tested peptides. These results indicate that we have developed a highly specific multiplex assay based of chimeric citrullinated peptides derived from filaggrin, fibrin, vimentin and human enolase proteins for the detection of ACPAs in a serum-saving way.