Lupus nephritis is linked to disease-activity associated expansions and immunity to a gut commensal.

BACKGROUND/PURPOSE: To search for a transmissible agent involved in lupus pathogenesis, we investigated the faecal microbiota of patients with systemic lupus erythematosus (SLE) for candidate pathobiont(s) and evaluated them for special relationships with host immunity. METHODS: In a cross-sectional discovery cohort, matched blood and faecal samples from 61 female patients with SLE were obtained. Faecal 16 S rRNA analyses were performed, and sera profiled for antibacterial and autoantibody responses, with findings validated in two independent lupus cohorts. RESULTS: Compared with controls, the microbiome in patients with SLE showed decreased species richness diversity, with reductions in taxonomic complexity most pronounced in those with high SLE disease activity index (SLEDAI). Notably, patients with SLE had an overall 5-fold greater representation of Ruminococcus gnavus (RG) of the Lachnospiraceae family, and individual communities also displayed reciprocal contractions of a species with putative protective properties. Gut RG abundance correlated with serum antibodies to only 1/8 RG strains tested. Anti-RG antibodies correlated directly with SLEDAI score and antinative DNA levels, but inversely with C3 and C4. These antibodies were primarily against antigen(s) in an RG strain-restricted pool of cell wall lipoglycans. Novel structural features of these purified lipoglycans were characterised by mass spectrometry and NMR. Highest levels of serum anti-RG strain-restricted antibodies were detected in those with active nephritis (including Class III and IV) in the discovery cohort, with findings validated in two independent cohorts. CONCLUSION: These findings suggest a novel paradigm in which specific strains of a gut commensal may contribute to the immune pathogenesis of lupus nephritis.

TP53 Combined Phenotype Score Is Associated with the Clinical Outcome of TP53-Mutated Myelodysplastic Syndromes.

Mutations of TP53 are observed in 5-10% of patients in myelodysplastic syndrome (MDS) and are associated with adverse outcomes. Previous studies indicate that the TP53 allelic state and variant allele frequency of TP53 mutation impact patient outcomes, but there is significant heterogeneity within this MDS subgroup. We performed retrospective review of clinicopathologic and genomic information of 107 patients with TP53-mutated MDS. We assessed each mutation according to the phenotypic annotation of TP53 mutations (PHANTM) and analyzed the associations between predicted TP53 mutant function, represented by the PHANTM combined phenotype score, and overall survival (OS) using the log rank test and Cox regression. Our results indicated that patients with PHANTM combined phenotype score above the median (>1) had significantly shorter OS compared to those with scores below the median (median OS: 10.59 and 16.51 months, respectively, p = 0.025). This relationship remained significant in multivariable analysis (HR (95%CI): 1.62 (1.01-2.58), p = 0.044) and identified to have an independent prognostic influence, accounting for known risk such as IPSS-R and other standard risk variables. Our results suggest that the functional information of TP53 mutations, represented by PHANTM combined phenotype score, are associated with the clinical outcome of patients with TP53-mutated MDS.