Prevalence of monoclonal gammopathy of undetermined significance in eswatini: a Population-Based study in africa.

PURPOSE: Although monoclonal gammopathy of undetermined significance (MGUS) and multiple myeloma disproportionately affect Black individuals, few epidemiologic studies have been conducted on these plasma cell disorders in Africa. Here we describe the prevalence of MGUS in Eswatini and compare our results to the landmark Olmsted County, USA study. METHODS: Between 2016 and 2017, 13,339 residents of Eswatini participated in the Swaziland HIV Incidence Measurement Survey, from which a nationally-representative biorepository was created. Plasma samples were then randomly selected and analyzed for MGUS. MGUS prevalence in Eswatini was compared to that of Olmsted County. Additionally, demographic and HIV-related associations with MGUS were assessed. RESULTS: Of the 515 samples randomly selected, the median age was 50 years (range 35-80) and 60% were female; 38.6% were HIV-positive, of whom 82.4% were on antiretroviral therapy. We found that 68 had evidence of MGUS for a prevalence of 13.2%. HIV status was not significantly associated with MGUS (OR, 1.05; 95%CI, 0.62-1.77), but among HIV-positive individuals, MGUS was less frequent for those on antiretroviral therapy (adjusted OR, 0.31; 95%CI, 0.11-0.82). The prevalence of conventional MGUS was similar between Eswatini and Olmsted County (3.4% vs 3.2-3.4%), while light-chain MGUS was significantly greater in Eswatini (12.3% vs 0.8%). CONCLUSION: Our study suggests that the incidence of MGUS is similar between ethnicities and raises the question of whether the current definition of light-chain MGUS reliably reflects a true monoclonal protein precursor state. Perhaps the current definition of light-chain MGUS may be capturing alternate etiologies, such as untreated HIV infection.

Self-Renewing CD8+ T-cell Abundance in Blood Associates with Response to Immunotherapy.

Treatment with immune checkpoint blockade (ICB) often fails to elicit durable antitumor immunity. Recent studies suggest that ICB does not restore potency to terminally dysfunctional T cells, but instead drives proliferation and differentiation of self-renewing progenitor T cells into fresh, effector-like T cells. Antitumor immunity catalyzed by ICB is characterized by mobilization of antitumor T cells in systemic circulation and tumor. To address whether abundance of self-renewing T cells in blood is associated with immunotherapy response, we used flow cytometry of peripheral blood from a cohort of patients with metastatic non-small cell lung cancer (NSCLC) treated with ICB. At baseline, expression of T-cell factor 1 (TCF1), a marker of self-renewing T cells, was detected at higher frequency in effector-memory (CCR7-) CD8+ T cells from patients who experienced durable clinical benefit compared to those with primary resistance to ICB. On-treatment blood samples from patients benefiting from ICB also exhibited a greater frequency of TCF1+CCR7-CD8+ T cells and higher proportions of TCF1 expression in treatment-expanded PD-1+CCR7-CD8+ T cells. The observed correlation of TCF1 frequency in CCR7-CD8+ T cells and response to ICB suggests that broader examination of self-renewing T-cell abundance in blood will determine its potential as a noninvasive, predictive biomarker of response and resistance to immunotherapy.

IFN-γR/STAT1 signaling in recipient hematopoietic antigen-presenting cells suppresses graft-versus-host disease.

The absence of IFN-γ receptor (IFN-γR) or STAT1 signaling in donor cells has been shown to result in reduced induction of acute graft-versus-host disease (GVHD). In this study, we unexpectedly observed increased activation and expansion of donor lymphocytes in both lymphohematopoietic organs and GVHD target tissues of IFN-γR/STAT1-deficient recipient mice, leading to rapid mortality following the induction of GVHD. LPS-matured, BM-derived Ifngr1-/- Stat1-/- DCs (BMDCs) were more potent allogeneic stimulators and expressed increased levels of MHC II and costimulatory molecules. Similar effects were observed in human antigen-presenting cells (APCs) with knockdown of Stat1 by CRISPR/Cas9 and treatment with a JAK1/2 inhibitor. Furthermore, we demonstrated that the absence of IFN-γR/STAT1 signaling in hematopoietic APCs impaired the presentation of exogenous antigens, while promoting the presentation of endogenous antigens. Thus, the indirect presentation of host antigens to donor lymphocytes was defective in IFN-γR/STAT1-deficient, donor-derived APCs in fully donor chimeric mice. The differential effects of IFN-γR/STAT1 signaling on endogenous and exogenous antigen presentation could provide further insight into the roles of the IFN-γ/STAT1 signaling pathway in the pathogenesis of GVHD, organ rejection, and autoimmune diseases.

Progression Rate From Intermediate to Advanced Age-Related Macular Degeneration Is Correlated With the Number of Risk Alleles at the CFH Locus.

PURPOSE: Progression rate of age-related macular degeneration (AMD) varies substantially, yet its association with genetic variation has not been widely examined. METHODS: We tested whether progression rate from intermediate AMD to geographic atrophy (GA) or choroidal neovascularization (CNV) was correlated with genotype at seven single nucleotide polymorphisms (SNPs) in the four genes most strongly associated with risk of advanced AMD. Cox proportional hazards survival models examined the association between progression time and SNP genotype while adjusting for age and sex and accounting for variable follow-up time, right censored data, and repeated measures (left and right eyes). RESULTS: Progression rate varied with the number of risk alleles at the CFH:rs10737680 but not the CFH:rs1061170 (Y402H) SNP; individuals with two risk alleles progressed faster than those with one allele (hazard ratio [HR] = 1.61, 95% confidence interval [CI] = 1.08-2.40, P < 0.02, n = 547 eyes), although this was not significant after Bonferroni correction. This signal was likely driven by an association at the correlated protective variant, CFH:rs6677604, which tags the CFHR1-3 deletion; individuals with at least one protective allele progressed more slowly. Considering GA and CNV separately showed that the effect of CFH:rs10737680 was stronger for progression to CNV. CONCLUSIONS: Results support previous findings that AMD progression rate is influenced by CFH, and suggest that variants within CFH may have different effects on risk versus progression. However, since CFH:rs10737680 was not significant after Bonferroni correction and explained only a relatively small portion of variation in progression rate beyond that explained by age, we suggest that additional factors contribute to progression.