Lyn Kinase Suppresses the Transcriptional Activity of IRF5 in the TLR-MyD88 Pathway to Restrain the Development of Autoimmunity.

Interferon regulatory factor-5 (IRF5), a transcription factor critical for the induction of innate immune responses, contributes to the pathogenesis of the autoimmune disease systemic lupus erythematosus (SLE) in humans and mice. Lyn, a Src family kinase, is also implicated in human SLE, and Lyn-deficient mice develop an SLE-like disease. Here, we found that Lyn physically interacted with IRF5 to inhibit ubiquitination and phosphorylation of IRF5 in the TLR-MyD88 pathway, thereby suppressing the transcriptional activity of IRF5 in a manner independent of Lyn's kinase activity. Conversely, Lyn did not inhibit NF-κB signaling, another major branch downstream of MyD88. Monoallelic deletion of Irf5 alleviated the hyperproduction of cytokines in TLR-stimulated Lyn(-/-) dendritic cells and the development of SLE-like symptoms in Lyn(-/-) mice. Our results reveal a role for Lyn as a specific suppressor of the TLR-MyD88-IRF5 pathway and illustrate the importance of fine-tuning IRF5 activity for the maintenance of immune homeostasis.

Erdheim-Chester disease: expanding the spectrum of cutaneous manifestations.

BACKGROUND: Erdheim-Chester disease (ECD) is a rare condition and there is limited information available regarding its cutaneous manifestations. OBJECTIVES: To describe the clinical and histopathological features of cutaneous involvement in ECD. METHODS: This study is a single-centre retrospective analysis of patients 18 years old and older with biopsy-proven diagnosis of ECD between 1 January 1990 and 1 April 2017. Patients from this cohort were screened for cutaneous manifestations, and BRAF c.1799T>A (p.V600E) mutational analysis was conducted in novel skin manifestations. Primary outcomes included cutaneous manifestations (morphology and topography of lesions) and BRAF mutation status in novel cutaneous findings. RESULTS: Of 71 patients with ECD, 15 patients (21%; median age 52 years) presented with cutaneous manifestations. The most common finding was the presence of xanthelasma-like lesions (n = 8). Two patients had nonfacial cutaneous xanthomas. Seven patients presented with nonxanthomatous cutaneous involvement, with the most common finding being subcutaneous nodules (n = 5). A single patient presented with granuloma annulare-like lesions. Another patient with mixed ECD and Langerhans cell histiocytosis presented with lightly scaling, pink-red macules. In three patients, the appearance of skin lesions was the first manifestation of the disease. Most patients presented with bone/extremity pain, weight loss and other constitutional symptoms at the time of diagnosis. The BRAF V600E mutation was not found in patients with panniculitis-like and granuloma annulare-like lesions. CONCLUSIONS: The most common presentation in ECD is the presence of periorbital xanthelasma-like lesions. Other presentations include nonfacial cutaneous xanthomas, panniculitis-like lesions and granuloma annulare-like lesions. Associated symptoms at presentation include bone/extremity pain and weight loss. What's already known about this topic? Erdheim-Chester disease is a rare form of non-Langerhans cell histiocytosis characterized by lipid-laden macrophage infiltration of tissue and subsequent fibrosis. Cutaneous involvement is found in approximately 25% of patients, with the majority presenting with periorbital xanthelasma-like lesions. What does this study add? We report two novel cutaneous findings: panniculitis-like lesions and granuloma annulare-like lesions. Associated bone/extremity pain and weight loss should raise suspicion for Erdheim-Chester disease.

Regulation and role of the transcription factor IRF5 in innate immune responses and systemic lupus erythematosus.

The transcription factor interferon regulatory factor-5 (IRF5) plays an important role in innate immune responses via the TLR-MyD88 (Toll-like receptor - myeloid differentiation primary response 88) pathway. IRF5 is also involved in the pathogenesis of the autoimmune disease systemic lupus erythematosus (SLE). Recent studies have identified new regulators, both positive and negative, which act on IRF5 activation events in the TLR-MyD88 pathway such as post-translational modifications, dimerization and nuclear translocation. A model of the causal relationship between IRF5 activation and SLE pathogenesis proposes that a loss of the negative regulation of IRF5 causes its hyperactivation, resulting in hyperproduction of type I interferons and other cytokines, and ultimately in the development of SLE. Importantly, to our knowledge, all murine models of SLE studied thus far have shown that IRF5 is required for the pathogenesis of SLE-like diseases. During the development of SLE-like diseases, IRF5 plays key roles in various cell types, including dendritic cells and B cells. It is noteworthy that the onset of SLE-like diseases can be inhibited by reducing the activity or amount of IRF5 by half. Therefore, IRF5 is an important therapeutic target of SLE, and selective suppression of its activity and expression may potentially lead to the development of new therapies.

Prevalence and predictors of thyroid functional abnormalities in newly diagnosed AL amyloidosis.

BACKGROUND: Data on the effect of systemic immunoglobulin light chain amyloidosis (AL amyloidosis) on thyroid function are limited. OBJECTIVE: To assess the prevalence of hypothyroidism in AL amyloidosis patients and determine its predictors. METHODS: 1142 newly diagnosed AL amyloidosis patients were grouped based on the thyroid-stimulating hormone (TSH) measurement at diagnosis: hypothyroid group (TSH above upper normal reference; >5 mIU L-1 ; n = 217, 19% of study participants) and euthyroid group (n = 925, 81%). Predictors for hypothyroidism were assessed in a binary multivariate model. Survival between groups was compared using the log-rank test and a multivariate analysis. RESULTS: Patients with hypothyroidism were older, more likely to present with renal and hepatic involvement and had a higher light chain burden compared to patients in the euthyroid group. Higher proteinuria in patients with renal involvement and lower albumin in patients with hepatic involvement were associated with hypothyroidism. In a binary logistic regression model, age ≥65 years, female sex, renal involvement, hepatic involvement, kappa light chain restriction and amiodarone use were independently associated with hypothyroidism. Ninety-three per cent of patients in the hypothyroid group with free thyroxine measurement had normal values, consistent with subclinical hypothyroidism. Patients in the hypothyroid group had a shorter survival compared to patients in the euthyroid group (4-year survival 36% vs 43%; P = 0.008), a difference that was maintained in a multivariate analysis. CONCLUSION: A significant proportion of patients with AL amyloidosis present with hypothyroidism, predominantly subclinical, which carries a survival disadvantage. Routine assessment of TSH in these patients is warranted.

Persistent infection with neurotropic herpes viruses and cognitive impairment.

BACKGROUND: Herpes virus infections can cause cognitive impairment during and after acute encephalitis. Although chronic, latent/persistent infection is considered to be relatively benign, some studies have documented cognitive impairment in exposed persons that is untraceable to encephalitis. These studies were conducted among schizophrenia (SZ) patients or older community dwellers, among whom it is difficult to control for the effects of co-morbid illness and medications. To determine whether the associations can be generalized to other groups, we examined a large sample of younger control individuals, SZ patients and their non-psychotic relatives (n=1852). Method Using multivariate models, cognitive performance was evaluated in relation to exposures to herpes simplex virus type 1 (HSV-1), herpes simplex virus type 2 (HSV-2) and cytomegalovirus (CMV), controlling for familial and diagnostic status and sociodemographic variables, including occupation and educational status. Composite cognitive measures were derived from nine cognitive domains using principal components of heritability (PCH). Exposure was indexed by antibodies to viral antigens. RESULTS: PCH1, the most heritable component of cognitive performance, declines with exposure to CMV or HSV-1 regardless of case/relative/control group status (p = 1.09 × 10-5 and 0.01 respectively), with stronger association with exposure to multiple herpes viruses (ß = -0.25, p = 7.28 × 10-10). There were no significant interactions between exposure and group status. CONCLUSIONS: Latent/persistent herpes virus infections can be associated with cognitive impairments regardless of other health status.

Alpha-2 macroglobulin is genetically associated with Alzheimer disease.

Alpha-2-macroglobulin (alpha-2M; encoded by the gene A2M) is a serum pan-protease inhibitor that has been implicated in Alzheimer disease (AD) based on its ability to mediate the clearance and degradation of A beta, the major component of beta-amyloid deposits. Analysis of a deletion in the A2M gene at the 5' splice site of 'exon II' of the bait region (exon 18) revealed that inheritance of the deletion (A2M-2) confers increased risk for AD (Mantel-Haenzel odds ratio=3.56, P=0.001). The sibship disequilibrium test (SDT) also revealed a significant association between A2M and AD (P=0.00009). These values were comparable to those obtained for the APOE-epsilon4 allele in the same sample, but in contrast to APOE-epsilon4, A2M-2 did not affect age of onset. The observed association of A2M with AD did not appear to account for the previously published linkage of AD to chromosome 12, which we were unable to confirm in this sample. A2M, LRP1 (encoding the alpha-2M receptor) and the genes for two other LRP ligands, APOE and APP (encoding the amyloid beta-protein precursor), have now all been genetically linked to AD, suggesting that these proteins may participate in a common neuropathogenic pathway leading to AD.

"Real-life" data of the efficacy and safety of belantamab mafodotin in relapsed multiple myeloma-the Mayo Clinic experience.

Belantamab mafodotin is a highly selective targeted therapy for multiple myeloma. It targets the B cell maturation antigen (BCMA) on plasma cells and showed promising results in several randomized clinical trials. We report the outcomes of 36 patients treated at Mayo Clinic. Our cohort received a median of eight prior lines of therapy. Six patients received belantamab in combination with other medications (pomalidomide, cyclophosphamide, thalidomide), 13 patients (36%) were 70 years or older, two patients had a creatinine of >2.5 mg/dL, and one patient was on dialysis. All three patients with renal failure received full dose belantamab. Chimeric antigen receptor (CAR-T) therapy was used prior to belantamab in seven patients and none of them responded to belantamab therapy. The overall response rate (ORR) was 33% (CR 6%, VGPR 8%, PR 19%), like the ORR reported in the DREAMM-2 trial. Keratopathy developed in 16 patients (43%), grade 1 in six patients, grade 2 in seven patients, and grade 3 in three patients. Eight percent discontinued therapy due to keratopathy. The median PFS and OS was 2 months and 6.5 months, respectively.

Irf5 siRNA-loaded biodegradable lipid nanoparticles ameliorate concanavalin A-induced liver injury.

RNA interference-based gene silencing drugs are attracting attention for treating various diseases. Lipid nanoparticles (LNPs) are carriers that efficiently deliver small interfering RNA (siRNA) to the cytoplasm of target cells. Recently, we developed potent and well-tolerated biodegradable LNPs with asymmetric ionizable lipids. Here, we evaluated the effect of LNPs on immune cells in mice. After intravenous administration, LNPs were efficiently incorporated into several tissue-resident macrophages, including liver macrophages, through an apolipoprotein E (ApoE)-independent mechanism. Administration of LNP-encapsulated siRNA against Irf5, encoding the transcription factor critical for inflammatory responses, sharply reduced its expression in macrophages in vivo, and persisted for as long as 7 days. The therapeutic potential of Irf5 siRNA-loaded LNPs in inflammatory diseases was tested in a concanavalin A (Con A)-induced hepatitis model, whose pathogenic mechanisms are dependent on cytokine secretion from macrophages. We found that Con A-induced liver injury was significantly attenuated after LNP injection. Serum aspartate transaminase, alanine aminotransferase, and inflammatory cytokine levels were significantly reduced in mice injected with Irf5 siRNA-loaded LNPs compared to those injected with control siRNA-loaded LNPs. Our results suggest that administering biodegradable LNPs to deliver siRNA is a promising strategy for treating inflammatory disorders.

Genetic and chemical inhibition of IRF5 suppresses pre-existing mouse lupus-like disease.

The transcription factor IRF5 has been implicated as a therapeutic target for the autoimmune disease systemic lupus erythematosus (SLE). However, IRF5 activation status during the disease course and the effects of IRF5 inhibition after disease onset are unclear. Here, we show that SLE patients in both the active and remission phase have aberrant activation of IRF5 and interferon-stimulated genes. Partial inhibition of IRF5 is superior to full inhibition of type I interferon signaling in suppressing disease in a mouse model of SLE, possibly due to the function of IRF5 in oxidative phosphorylation. We further demonstrate that inhibition of IRF5 via conditional Irf5 deletion and a newly developed small-molecule inhibitor of IRF5 after disease onset suppresses disease progression and is effective for maintenance of remission in mice. These results suggest that IRF5 inhibition might overcome the limitations of current SLE therapies, thus promoting drug discovery research on IRF5 inhibitors.

Linkage analysis of schizophrenia in African-American families.

While many studies have sought a window into the genetics of schizophrenia, few have focused on African-American families. An exception is the Project among African-Americans to Explore Risks for Schizophrenia (PAARTNERS), which seeks to identify novel and known risk variation for schizophrenia by genetic analyses of African-American families. We report a linkage study of diagnostic status in 217 African-American families using the Illumina Linkage Panel. Due to assumed incomplete and time-dependent penetrance, we performed linkage analysis using two different treatments of diagnosis: (1) treating both affected and unaffected individuals as informative for linkage (using the program SIBPAL) and (2) treating only affected individuals as informative (using the program MERLIN). We also explore three definitions of affected status: narrowly defined schizophrenia; one broadened to include schizoaffective disorder; and another including all diagnoses indicating psychosis. Several regions show a decrease in the evidence for linkage as the definition broadens 8q22.1 (rs911, 99.26 cM; SIBPAL p-value [p] goes from 0.006 to 0.02), 16q24.3 (rs1006547, 130.48 cM; p from 0.00095 to 0.0085), and 20q13.2 (rs1022689, 81.73 cM; p from 0.00015 to 0.032). One region shows a substantial increase in evidence for linkage, 11p15.2 (rs722317, 24.27 cM; p from 0.0022 to 0.0000003); MERLIN results support the significance of the SIBPAL results (p=0.00001). Our linkage results overlap two broad, previously-reported linkage regions: 8p23.3-p12 found in studies sampling largely families of European ancestry; and 11p11.2-q22.3 reported by a study of African-American families. These results should prove quite useful for uncovering loci affecting risk for schizophrenia.

Allele increasing susceptibility to human breast cancer may be linked to the glutamate-pyruvate transaminase locus.

The patterns of the occurrence of breast cancer in 11 high-risk families were evaluated by segregation and linkage analysis. These patterns were consistent with the hypothesis that increased susceptibility to breast cancer was inherited as an autosomal dominant allele with high penetrance in women. The postulated susceptibility allele in these families may be chromosomally linked to the glutamate-pyruvate transaminase (E.C. 2.6.1.2, alanine aminotransferase) locus. Confirmation of this linkage in other families would establish the existence of a gene increasing susceptibility to breast cancer. Since there is no association in the general population between a woman's glutamate-pyruvate transaminase genotype and her cancer risk, the glutamate-pyruvate transaminase linkage cannot be used as a screening test for breast cancer.

Evidence for genetic linkage of Alzheimer's disease to chromosome 10q.

Recent studies suggest that insulin-degrading enzyme (IDE) in neurons and microglia degrades Abeta, the principal component of beta-amyloid and one of the neuropathological hallmarks of Alzheimer's disease (AD). We performed parametric and nonparametric linkage analyses of seven genetic markers on chromosome 10q, six of which map near the IDE gene, in 435 multiplex AD families. These analyses revealed significant evidence of linkage for adjacent markers (D10S1671, D10S583, D10S1710, and D10S566), which was most pronounced in late-onset families. Furthermore, we found evidence for allele-specific association between the putative disease locus and marker D10S583, which has recently been located within 195 kilobases of the IDE gene.

Clinical presentation and outcomes in light chain amyloidosis patients with non-evaluable serum free light chains.

Hematologic response criteria in light chain (AL) amyloidosis require the difference in involved and uninvolved free light chains (dFLC) to be at least 5 mg/dl. We describe the clinical presentation and outcomes of newly diagnosed amyloidosis patients with dFLC <5 mg/dl (non-evaluable dFLC; 14%, n=165) compared with patients with dFLC ⩾5 mg/dl (evaluable dFLC; 86%, n=975). Patients with non-evaluable dFLC had less cardiac involvement (40% vs 80%, P<0.001), less liver involvement (11% vs 17%, P=0.04) and a trend toward less gastrointestinal involvement (18% vs 25%, P=0.08). However, significantly higher renal involvement (72% vs 56%, P=0.0002) was observed in the non-evaluable dFLC cohort. Differences in treatment patterns were observed, with 51% of treated patients undergoing upfront stem cell transplantation in the non-evaluable cohort compared with 28% in the evaluable dFLC group (P<0.001). Progression-free survival (61 vs 13 months, P<0.001) and overall survival (OS; 101 vs 29 months, P<0.001) were significantly longer in the non-evaluable dFLC cohort. Normalization of involved light chain levels and decrease in dFLC <1 mg/dl (baseline at least 2 mg/dl) were predictive of OS and associated with better dialysis-free survival and may be used for response assessment in patients with non-evaluable FLC levels.

Pomalidomide-dexamethasone in refractory multiple myeloma: long-term follow-up of a multi-cohort phase II clinical trial.

Despite therapeutic advances, multiple myeloma remains incurable, with limited options for patients with refractory disease. We conducted a large, multi-cohort clinical trial testing various doses and treatment schedules of pomalidomide and dexamethasone (Pom/dex) in patients with refractory multiple myeloma. Overall, 345 patients were enrolled to six cohorts based on number and type of prior lines of therapy, pomalidomide dose and schedule. Median prior lines of therapy were three with near universal prior exposure to proteasome inhibitors and/or immunomodulatory drugs. A confirmed response rate of 35% was noted for all cohorts (range 23-65%) with higher responses in cohorts with fewer prior lines of therapy. Median time to confirmed response was ⩽2 months and the longest progression-free survival and overall survival seen in any cohort were 13.1 and 47.9 months, respectively. Observed adverse reactions were as expected, with myelosuppression and fatigue being the most common hematologic and non-hematologic adverse events (AEs), respectively. Longer durations of treatment and response, higher response rates and fewer AEs were noted with the 2 mg pomalidomide dose. This is the longest follow-up data for Pom/dex in refractory multiple myeloma and will help shape the real-world utilization of this regimen.

Natural history of t(11;14) multiple myeloma.

Translocation (11;14) on interphase fluorescent in situ hybridization in plasma cells is regarded as a standard risk prognostic marker in multiple myeloma based on studies conducted before introduction of current therapies. We identified 365 patients with t(11;14), and 730 matched controls:132 patients with non-(11;14) translocations and 598 patients with no chromosomal translocation. The median progression-free survival for the three groups were 23.0 (95% confidence interval (CI), 20.8-27.6), 19.0 (95% CI, 15.8-22.7) and 28.3 (95% CI, 25.7-30.6) months, respectively (P<0.01). The median overall survival (OS) for t(11;14), non-(11;14) translocation and no-translocation groups were 74.4 (95% CI, 64.8-89.3), 49.8 (95% CI, 40.0-60.6) and 103.6 (95% CI, 85.2-112.3) months, respectively (P<0.01). Excluding those with 17p abnormality, the median OS in the three groups were 81.7 (95% CI, 67.0-90.7), 58.2 (95% CI, 47.0-76.4) and 108.3 (95% CI, 92.4-140.1) months, respectively (P<0.01). The above relationship held true in patients with age <65 years, international staging system (ISS) I/II stage or those who received novel agent-based induction. Advanced age (hazard ratio (HR): 1.98), 17p abnormality (HR: 2.2) and ISS III stage (HR: 1.59) at diagnosis predicted reduced OS in patients with t(11;14). These results suggest that outcomes of t(11;14) MM are inferior to other standard risk patients.

A polymorphism in SOD2 is associated with development of Alzheimer's disease.

Genes involved in cellular mechanisms to repair oxidative damage are strong candidates as etiologic factors for Alzheimer's disease (AD). One important enzyme involved in this mechanism is superoxide dismutase 2 (SOD2). The gene for this enzyme lies within a single haplotype block at 6q25.3, a region showing evidence for linkage to AD in a genome scan. We genotyped four single nucleotide polymorphisms (SNPs) in SOD2 in families of the National Institute of Mental Health-AD Genetics Initiative (ADGI): rs2758346 in the 5' untranslated region (UTR), rs4880 in exon 2, rs2855116 in intron 3 and rs5746136 in the 3'UTR. Under a dominant model, family-based association tests showed significant evidence for association of AD with the first three loci in a candidate gene set of families with individuals having age of onset of at least 50 years and two affected and one unaffected sibling, and in a late-onset subset of families (families with all affected individuals having age of onset of at least 65 years) from the full ADGI sample. The alleles transmitted more frequently to cases than expected under the null hypothesis were T, C, G, and G. Global tests of the transmission of haplotypes indicate that the first two loci have the most consistent association with risk of AD. Because of the high linkage disequilibrium in this small (14 kb) gene, and the presence of 100 SNPs in this gene, 26 of which may have functional significance, additional genotyping and sequencing are needed to identify the functionally relevant SNP. We discuss the importance of our findings and the relevance of SOD2 to AD risk.

Rapid determination of clonality by detection of two closely-linked X chromosome exonic polymorphisms using allele-specific PCR.

We reported two specific, reproducible, and quantitative clonality assays based on detection of exonic polymorphisms of the X chromosome genes p55 and G6PD using rtPCR-LDR. These assays are inconvenient for screening purposes. This study sought to develop a simple, reproducible assay, practical for screening genomic DNA samples for p55/G6PD genotypes, rapid clonality determination, and to determine the linkage relationship between these closely related loci. The salient feature of ASPCR is the performance of two PCR rounds. The first generates template; the second, using one aliquot of first-round products in two reaction tubes, each containing one allele-specific primer, detects each allele. ASPCR and rtPCR-LDR produced identical p55/G6PD results in 91 normal female genomic DNAs, and in 12 clonal hematopoietic disorder cDNAs, confirming assay validity. 209 female and 207 male genomic DNA samples were analyzed for p55/G6PD genotype by ASPCR; 60% of females were heterozygous at one or both loci. G6PD and p55 allelic frequencies were significantly different among African-American men and women, but were not significantly different among Caucasian men and women. These loci were in linkage equilibrium among African Americans, but not among Caucasians. ASPCR is a rapid, sensitive, and specific method for screening large numbers of genomic DNAs, and for rapid clonality determination.

Major histocompatibility complex class III genes and susceptibility to immunoglobulin A deficiency and common variable immunodeficiency.

We have proposed that significant subsets of individuals with IgA deficiency (IgA-D) and common variable immunodeficiency (CVID) may represent polar ends of a clinical spectrum reflecting a single underlying genetic defect. This proposal was supported by our finding that individuals with these immunodeficiencies have in common a high incidence of C4A gene deletions and C2 rare gene alleles. Here we present our analysis of the MHC haplotypes of 12 IgA-D and 19 CVID individuals from 21 families and of 79 of their immediate relatives. MHC haplotypes were defined by analyzing polymorphic markers for 11 genes or their products between the HLA-DQB1 and the HLA-A genes. Five of the families investigated contained more than one immunodeficient individual and all of these included both IgA-D and CVID members. Analysis of the data indicated that a small number of MHC haplotypes were shared by the majority of immunodeficient individuals. At least one of two of these haplotypes was present in 24 of the 31 (77%) immunodeficient individuals. No differences in the distribution of these haplotypes were observed between IgA-D and CVID individuals. Detailed analysis of these haplotypes suggests that a susceptibility gene or genes for both immunodeficiencies are located within the class III region of the MHC, possibly between the C4B and C2 genes.