Endomyocardial biopsies in the diagnosis of myocardial involvement in systemic lupus erythematosus.

BACKGROUND: Endomyocardial biopsy (EMB) is considered the gold standard for diagnosing myocardial involvement in most inflammatory conditions, including systemic lupus erythematosus (SLE). However, EMBs are rarely performed, and most of the myocardial histopathology reports in SLE consist of postmortem data. We therefore sought to describe the histopathologic findings of contemporary EMBs in SLE performed in clinical practice. METHODS: A retrospective review of histopathology reports from SLE patients who underwent EMB from 1994 to 2017 was performed. A total of 41 SLE patients had cardiac pathology reports. Of these, 11 histopathology reports were EMBs, and the remaining were valvular specimens. RESULTS: A total of 11 SLE EMBs were reviewed. It was found that 45% of the patients had hypertension, 27% had coronary artery disease, 9% had hyperlipidemia, and 36% had end-stage renal disease. None had diabetes or smoked. The mean left ventricular ejection fraction was 37%. On histopathology, 10 had mild interstitial fibrosis, 9 had myocyte hypertrophy, 3 had organized blood clots, and 3 had a mild infiltration of lymphocytes and macrophages without clear evidence of myocarditis. None had vasculitis, endocarditis, ischemia, amyloid deposition, or lamellar or curvilinear inclusions. CONCLUSION: EMBs are rarely performed in SLE. In this case series, nonspecific interstitial fibrosis and myocyte hypertrophy were the most common findings, suggesting EMBs have limited value in the diagnosis of cardiac involvement in SLE and rather rule out competing conditions. These data support the need for diagnostic methods with high sensitivity and specificity for SLE heart disease.

Origin of Enriched Regulatory T Cells in Patients Receiving Combined Kidney-Bone Marrow Transplantation to Induce Transplantation Tolerance.

We examined tolerance mechanisms in patients receiving HLA-mismatched combined kidney-bone marrow transplantation (CKBMT) that led to transient chimerism under a previously published nonmyeloablative conditioning regimen (Immune Tolerance Network study 036). Polychromatic flow cytometry and high-throughput sequencing of T cell receptor-ß hypervariable regions of DNA from peripheral blood regulatory T cells (Tregs) and CD4 non-Tregs revealed marked early enrichment of Tregs (CD3+ CD4+ CD25high CD127low Foxp3+ ) in blood that resulted from peripheral proliferation (Ki67+ ), possibly new thymic emigration (CD31+ ), and, in one tolerant subject, conversion from non-Tregs. Among recovering conventional T cells, central memory CD4+ and CD8+ cells predominated. A large proportion of the T cell clones detected in posttransplantation biopsy specimens by T cell receptor sequencing were detected in the peripheral blood and were not donor-reactive. Our results suggest that enrichment of Tregs by new thymic emigration and lymphopenia-driven peripheral proliferation in the early posttransplantation period may contribute to tolerance after CKBMT. Further, most conventional T cell clones detected in immunologically quiescent posttransplantation biopsy specimens appear to be circulating cells in the microvasculature rather than infiltrating T cells.

Description of two new HLA-C alleles in a black South African population.

Two new HLA-C alleles, Cw*0333 and Cw*0217, were identified in a Black South African population. HLA-Cw*0333 differs from Cw*030201 by an A-->G substitution at nucleotide 323, yielding an unusual missense substitution of Cys for the conserved Tyr-84 at the antigen cleft terminus. Molecular modeling suggests that this alters the predicted interactions of this critical residue with the opposite alpha(2)-helix, the peptide COOH terminus and possibly KIR2DL2. The second allele, Cw*0217, differs from Cw*0205 by an A-->T substitution at nucleotide 368, resulting in a Tyr-->Phe substitution at residue 99 of the HLA-C beta-pleated sheet that likely influences peptide side-chain binding. Both Cw*0333 and Cw*0217 appear to have arisen by missense mutations, respectively, from the HLA-B*5801-Cw*0302 and B*080101-Cw*0205 haplotypes.

Regulatory CD8+ T cells fine-tune the myelin basic protein-reactive T cell receptor V beta repertoire during experimental autoimmune encephalomyelitis.

A significant number of self-reactive T cell clones escape thymic negative selection and are released into the periphery, where some are potentially pathogenic. The clonal expansion of self-reactive T cells is known to be limited during initial antigen encounter by apoptotic or anergic mechanisms, regulatory CD4+ T cells, and cytokines. Here we report that superimposed on these mechanisms, during the evolution of autoimmunity in experimental autoimmune encephalomyelitis (EAE), CD8+ T cells are induced, which fine-tune the peripheral self-reactive T cell receptor (TCR) repertoire. We assayed the myelin basic protein-reactive TCR repertoire in naive, EAE-recovered mice as well as EAE-recovered mice depleted of CD8+ T cells by TCRV beta surface expression, complementarity-determining region 3 length distribution, and complementarity-determining region 3 sequencing analysis. In EAE-recovered mice, certain myelin basic protein-reactive CD4+V beta 8.2+ clones are significantly decreased and this decrease is not observed if CD8+ T cells were depleted from these mice. The clones that persist in CD8+ T cell-intact mice are highly diverse in contrast to the clones expanded in CD8+ T cell-depleted mice, which are dominated by the significant outgrowth of a few clones. Importantly, the T cell clones that expand in the absence of CD8+ T cell control are enriched in potentially pathogenic self-reactive T cell clones capable of inducing EAE in vivo.

The IDDM13 region containing the insulin-like growth factor binding protein-5 (IGFBP5) gene on chromosome 2q33-q36 and the genetic susceptibility to rheumatoid arthritis.

We considered that the constitutive over-expression by cultured rheumatoid arthritis (RA) fibroblast-lineage synoviocytes of genes like IGFBP5 could indicate new candidate susceptibility genes. IGFBP5 is located in a region where an insulin-dependent diabetes mellitus (IDDM) susceptibility locus, IDDM13 (2q33-q36), has been mapped. Previous evidence that non-MHC IDDM loci overlap RA susceptibility loci made IGFBP5 and its region an interesting candidate locus which was tested for linkage. Forty-nine sibships (2-4 affected siblings per sibship) with RA were genotyped with microsatellite markers covering an 11.2 cM interval in the IGFBP5/IDDM13 region. Both the two-point LOD scores and a 'nonparametric' allele-sharing analysis revealed no evidence for linkage (max LOD = 0.54, P = 0.5, respectively). Adjustments for the presence of 'shared-epitope' alleles did not significantly change the LOD scores. These results suggest that, despite the involvement of the 2q33-q36 chromosomal region in another organ-specific autoimmune disease, it is unlikely that this region harbors a RA susceptibility locus.

CD8+ T cells control the TH phenotype of MBP-reactive CD4+ T cells in EAE mice.

Trimolecular interactions between the T cell antigen receptor and MHC/peptide complexes, together with costimulatory molecules and cytokines, control the initial activation of naive T cells and determine whether the helper precursor cell differentiates into either T helper (TH)1 or TH2 effector cells. We now present evidence that regulatory CD8(+) T cells provide another level of control of TH phenotype during further evolution of immune responses. These regulatory CD8(+) T cells are induced by antigen-triggered CD4(+) TH1 cells during T cell vaccination and, in vitro, distinguish mature TH1 from TH2 cells in a T cell antigen receptor Vbeta-specific and Qa-1-restricted manner. In vivo, protection from experimental autoimmune encephalomyelitis (EAE) induced by T cell vaccination depends on CD8(+) T cells, and myelin basic protein-reactive TH1 Vbeta8(+) clones, but not TH2 Vbeta8(+) clones, used as vaccine T cells, protect animals from subsequent induction of EAE. Moreover, in vivo depletion of CD8(+) T cells during the first episode of EAE results in skewing of the TH phenotype toward TH1 upon secondary myelin basic protein stimulation. These data provide evidence that CD8(+) T cells control autoimmune responses, in part, by regulating the TH phenotype of self-reactive CD4(+) T cells.

Psoriatic arthritis joint fluids are characterized by CD8 and CD4 T cell clonal expansions appear antigen driven.

The CD8 alphabetaT cell receptor repertoire in joint fluid of individuals with active psoriatic arthritis contained an average of 32 major oligoclonal expansions in many variable genes of the TCR beta chain (BV) families, as shown by beta-chain CDR3 length analysis. Interestingly, a small number of oligoclonal expansions were shared between simultaneous samples of joint fluid and blood; however, most expansions found in joint fluid were not identifiable in blood emphasizing the immunologic specificity of the clonal events for the inflamed joint at a given point of time. The CD4 T cell joint fluid repertoire contained fewer and smaller oligoclonal expansions also largely restricted to the joint, suggesting that CD4 T cells participate perhaps by interacting cognitively to generate the CD8 clones. The inferred amino acid sequence of a single CD8 oligoclonal expansion revealed that they usually are composed of one or a few structurally related clones at the amino acid sequence level with beta-chains that encode identical or highly homologous CDR3 motifs. These were not shared among patients. Moreover, several clones that encoded the same amino acid sequence were found to be structurally distinct at the nucleotide level, strongly implying clonal selection and expansion is operating at the level of specific TCR-peptide interactions. The findings support a model of psoriatic arthritis inflammation involving extensive and selective Ag, likely autoantigen, driven intra-articular CD4, and CD8 T cell clonal expansions.

Psoriatic arthritis and the spectrum of syndromes related to the SAPHO (synovitis, acne, pustulosis, hyperostosis, and osteitis) syndrome.

During the past year, the increasing use of nuclear magnetic resonance imaging techniques, with their ability to delineate cartilage and ligamentous structures and to identify edema, are providing a radical improvement in ascertainment of musculoskeletal abnormalities, although their significance remains incompletely delineated. A second theme has come from the study of spondyloarthropathies in different ethnic groups and societal environments, revealing that the Northern European and North American form of the disease, with its powerful association with HLA-B27, is little evident in the rest of the world's population and that different susceptibility genes and environmental factors operate in other regions and peoples. Related to this theme is the compelling evidence of the marked influence of HIV infection on the development of spondyloarthropathies in Africa. Two areas of immune recognition are discussed as examples of emerging fields that may provide useful paradigms for the experimental approach to mechanisms in psoriatic arthritis. One of these is the three-cell model of CD8 T-cell interaction, in which a dendritic cell presents a peptide from an immunogenic protein to both a CD4 and CD8 T-cell clone, providing a cognitive interaction that disrupts tolerance and results in the expansion of the cytotoxic T-cell clone. In this respect, the combination of an activated dendritic cell, together with enhanced availability of arthritogenic microbial antigens caused by microbial persistence, are interesting candidates to explore as the basis of the HIV-associated rheumatic diseases. The second area of immune recognition is the growing understanding of the outline of the solution to the problem of the association of a spondyloarthropathy with several

Use of differential subtraction method to identify genes that characterize the phenotype of cultured rheumatoid arthritis synoviocytes.

OBJECTIVE: To identify the genes that characterize the distinctive phenotype of cultured rheumatoid arthritis (RA) fibroblastoid synoviocytes. METHODS: A representational difference method was used to subtract complementary DNA (cDNA) from cultured RA fibroblastoid synoviocytes with cDNA from noninflammatory osteoarthritis synoviocytes. The genes were identified by DNA sequencing, and their relative expression was determined by Northern blot analysis. RESULTS: Twenty-four genes were identified, including novel genes such as a human homolog of mouse semaphorin E and one homologous to N-acetylglucosamine-6-sulfatase. Eleven of these genes were constitutively overexpressed in the rheumatoid synoviocyte line, including a chemokine, stromal cell-derived factor 1, and several genes capable of mediating synoviocyte-leukocyte interactions, including vascular cell adhesion molecule 1 and Mac-2 binding protein. Three genes (lumican, biglycan, and insulin-like growth factor binding protein 5) encoded extracellular matrix components, suggesting that distinct stromal-synoviocyte interactions may be mediated by this phenotype. Two interferon-inducible genes of unknown function were also found, emphasizing the presence of activation-like features in the phenotype. CONCLUSION: A general method for the identification of differences in patterns of gene expression revealed that cultured RA fibroblastoid synoviocytes overexpress certain proinflammatory genes that are potentially relevant to lymphocyte and monocyte entry and interactions. The features of the genes identified in these mesenchymal cells suggest that they facilitate localization of immune reactions to the joint through leukocyte chemokinesis, cell-cell adhesion, and matrix specialization. The further characterization of these genes should help in resolving whether this phenotype is the consequence of modulation and imprinting by an inflammatory milieu or, more likely, whether it reflects the intrinsic lineage characteristics of intimal lining synoviocytes.

Influence of HLA alleles on the rate of progression of vertically transmitted HIV infection in children: association of several HLA-DR13 alleles with long-term survivorship and the potential association of HLA-A*2301 with rapid progression to AIDS. Long-Term Survivor Study.

The influence of host immunogenetics on the outcome of vertically transmitted HIV infection in children was examined in a multicenter cross sectional study of long term survivors and rapid progressors. Sequence-based typing was performed for the DRB1, DQB1 and HLA-A loci. 36.7% of 30 children surviving more than 8 years had one or more of the HLA-DR13 alleles, versus none of 14 rapidly progressing children who died within 2 years of age, p = 0.009, Haldane RR = 17.1. The alleles variably associated with this beneficial response to HIV were: DRB1*1301, DRB1*1302, DRB1*1303 and DRB1*1310, suggesting that the DR13 effect acted as a dominant trait. An additional 6 children were typed only by the SSOP method resulting in 44.4% of 36 long term surviving children with a DR13 allele and none of 14 rapid progressors, p = 0.002, Haldane RR = 23.3. No single DQB1 allele accounted for the HLA-DR13 allele association. In contrast, the presence of HLA A*2301 was associated with rapid progression to AIDS, 4% of long term survivors vs. 57.1% of 7 rapid progressors, p = 0.0006, RR = 0.031. Although the sample size is small, the marked differences in allele frequency along with differences between the peptide binding pockets of the HLA-A9 group of alleles including HLA A*2301 and the remainder of the HLA-A alleles suggest a structural basis for the dominant disadvantageous immune response to HIV conferred by A*2301.

Interleukin 8 is induced by cholesterol loading of macrophages and expressed by macrophage foam cells in human atheroma.

In order to identify novel genes expressed in macrophage-derived foam cells, we used a multigene assay to examine the expression of genes in control versus cholesterol-loaded macrophages. We compared THP-1 macrophages incubated with or without acetylated LDL (acLDL) +/- acyl-CoA:cholesterol O-acyltransferase (ACAT) inhibitor (compound 58035) for 20 h and assessed changes in mRNA of chemokines, growth factors, interleukins, and adhesion molecules. Among 49 genes examined, an increase in mRNA was observed only for interleukin 8 (IL-8) in THP-1 macrophages. Northern analysis confirmed a 3- to 4-fold increase of IL-8 mRNA and an enzyme-linked immunosorbent assay (ELISA) revealed a corresponding increase in IL-8 in conditioned medium. Oxidized LDL (oxLDL) also induced IL-8 mRNA, but native LDL had no effect. 58035 had a moderate effect on IL-8 induction by acLDL. AcLDL-induced IL-8 expression was concentration- and time-dependent. The time course of IL-8 induction paralleled that of cholesterol loading. MCP-1, a chemokine implicated in recruiting monocytes in atherogenesis, was also induced by acLDL. The induction of MCP-1, however, peaked at 1 h after addition of acLDL and returned to basal level by 20 h while IL-8 induction peaked at 8 h and was still 2-fold higher than basal level at 20 h. IL-8 induction was also observed in fresh human monocyte-derived macrophage cells treated with acLDL. Finally, immunohistochemistry and in situ hybridization studies using specimens of human coronary atheromas showed expression of IL-8 mRNA in a macrophage-rich area. We conclude that IL-8 is induced in macrophage foam cells as a response to cholesterol loading. The chemoattractant and/or mitogenic effects of IL-8 on neutrophils, T cells, smooth muscle, or vascular endothelial cells may contribute to the progression and complications of atherosclerosis.

Major histocompatibility complex class II DR alleles DRB1*1501 and those encoding HLA-DR13 are preferentially associated with a diminution in maternally transmitted human immunodeficiency virus 1 infection in different ethnic groups: determination by an automated sequence-based typing method.

Transmission of human immunodeficiency virus 1 (HIV-1) from an infected women to her offspring during gestation and delivery was found to be influenced by the infant's major histocompatibility complex class II DRB1 alleles. Forty-six HIV-infected infants and 63 seroreverting infants, born with passively acquired anti-HIV antibodies but not becoming detectably infected, were typed by an automated nucleotide-sequence-based technique that uses low-resolution PCR to select either the simpler Taq or the more demanding T7 sequencing chemistry. One or more DR13 alleles, including DRB1*1301, 1302, and 1303, were found in 31.7% of seroreverting infants and 15.2% of those becoming HIV-infected [OR (odds ratio) = 2.6 (95% confidence interval 1.0-6.8); P = 0.048]. This association was influenced by ethnicity, being seen more strongly among the 80 Black and Hispanic children [OR = 4.3 (1.2-16.4); P = 0.023], with the most pronounced effect among Black infants where 7 of 24 seroreverters inherited these alleles with none among 12 HIV-infected infants (Haldane OR = 12.3; P = 0.037). The previously recognized association of DR13 alleles with some situations of long-term nonprogression of HIV suggests that similar mechanisms may regulate both the occurrence of infection and disease progression after infection. Upon examining for residual associations, only only the DR2 allele DRB1*1501 was associated with seroreversion in Caucasoid infants (OR = 24; P = 0.004). Among Caucasoids the DRB1*03011 allele was positively associated with the occurrence of HIV infection (P = 0.03).

Psoriatic arthritis.

Psoriatic arthritis and its associated enthesopathy appear to be another immune-mediated manifestation of the genetic predisposition to develop psoriasis. The occurrence of psoriatic arthritis in the setting of the selective immune deficiency of advanced HIV infection, especially in the association with HLA-B27, points to a role of the CD8 T cell in disease pathogenesis. The relationship of Reiter's syndrome to psoriatic arthritis is emphasized.

The role of the trimolecular complex (alpha beta TCR-MHC+peptide) in the pathogenesis of systemic sclerosis.

Systemic sclerosis is an intricate disease process whose most unique and specific parameter indicative of autoimmunity is the presence of autoantibodies directed against certain nuclear antigens. The relationship between this particular humoral immune response and the genesis of a fibrotic tissue response in the skin as well as internal organs is not yet well understood. The prominence of CD4 T-cell infiltration during early phases of disease suggest that activation pathways may be initiated which subsequently result in phenotypic changes of a variety of mesenchymal cells, especially endothelial cells and fibroblasts. Taken in concert with the association of susceptibility with certain MHC class II molecules, the conventional presenters of exogenous peptide to T cells of the CD4 lineage, the notion of a central critical immune recognition event underlying the development of systemic sclerosis gains increasing likelihood. In addition to the still incompletely understood paracrine pathways between immune response and fibrosis, there is a nearly complete void of knowledge concerning what peptide is recognized by the T-cell and the structure of the alpha beta TCR involved in this recognition. Determining the role of the alpha beta TCR in the activation of the T-cell population in terms of identifying structural features which are critical participants in this process and the functional derangement leading to the characteristic pattern of self recognition will certainly enhance our understanding of the pathogenesis of systemic sclerosis.

Grouping HLA-B locus serologic specificities according to shared structural motifs suggests that different peptide-anchoring pockets may have contrasting influences on the course of HIV-1 infection.

Two different groups of HLA-B specificities were associated with two contrasting outcomes of HIV-1 infection. HLA-B45, -B49, and -B50 were each found at a moderately increased frequency among individuals responding to HIV-1 infection with a marked circulating and infiltrative CD8 T-cell lymphocytosis, a slow rate of CD4 T-cell decline, very low frequency of opportunistic infections, and low viral strain heterogeneity. In contrast, among HIV-infected individuals with more rapid progression to opportunistic infections, HLA-B35 was found to be increased in frequency and to act as a dominant marker for this adverse outcome. HLA-B45, -B49, and -B50 contain identical peptide-anchoring "B" and "C-terminal" pocket structures, which differ greatly from those present in HLA-B35, implying that different immunogenic peptides are likely to be bound by these two groups of alleles. Placing HLA-B45, -B49, and -B50 into one structurally defined group revealed a much stronger and statistically significant association with the CD8 lymphocytosis syndrome (OR = 5.3, p = 0.0005). The B pocket structure in these alleles contains an easily accessible lysine residue at position 45, suggesting that the P2 or P3 anchor residue of a bound peptide is negatively charged. Additionally, by observing the effect on the ORs of adding structures containing amino acid substitutions in the C-terminal pocket of HLA-B45, -B49, and -B50, this region was also shown to influence susceptibility to this host response.(ABSTRACT TRUNCATED AT 250 WORDS)

Human immunodeficiency virus type 1 strains in the lungs of infected individuals evolve independently from those in peripheral blood and are highly conserved in the C-terminal region of the envelope V3 loop.

To determine whether human immunodeficiency virus type 1 (HIV-1) strains in the lungs of infected individuals are derived from proviral forms contemporaneously present in the peripheral blood or whether they evolve independently as an autonomous pool of viral quasispecies, HIV-1 envelope V3 domain structures at these sites were analyzed and compared. The V3 loop proviral nucleotide and inferred amino acid sequences from lung bronchoalveolar lavage, where HIV-1 is primarily found in macrophages, were more homogeneous within individuals than those from unseparated peripheral blood mononuclear cells, where virus is predominantly in T cells. Comparison between individuals revealed that strains from bronchoalveolar lavage, but not from peripheral blood mononuclear cells, contained V3 domain nucleotide sequences with a great degree of homogeneity in the C-terminal region and a highly conserved, negatively charged amino acid motif. This V3 loop C-terminal structure could be important in the ability of HIV-1 to infect alveolar macrophages. Phylogenetic analyses of V3 domain nucleotide sequences in cells of monocyte/macrophage lineage at both sites revealed the strains in lung macrophages to have evolved further from a presumed ancestral species than those in blood monocytes and to differ considerably in the inferred V3 loop amino acid structures. These results show that, as disease progression occurs, viral strains in monocyte/macrophage lineage cells within the lung and blood microenvironments are not in a state of unrestricted bidirectional traffic but, instead, evolve independently.

Certain HLA-DR5 and -DR6 major histocompatibility complex class II alleles are associated with a CD8 lymphocytic host response to human immunodeficiency virus type 1 characterized by low lymphocyte viral strain heterogeneity and slow disease progression.

Either of two structurally related major histocompatibility complex class II alleles, DRB1*1102, which encodes a DR5 specificity, or DRB1*1301, which encodes a DR6 specificity, was found in 67% of individuals responding to human immunodeficiency virus type 1 (HIV-1) infection with a syndrome characterized by persistent circulating and diffusely infiltrative CD8 lymphocytosis (DILS), slow progression to opportunistic infections, and delayed CD4 T-cell depletion. These alleles were present in only 28% of ethnically matched HIV-positive controls (P = 0.001). The frequency of DRB1*1301 was increased in both Blacks and Caucasians with this syndrome, while that of DRBI*1102 was increased only in Blacks, where 80% had either of these alleles. To investigate whether the host response associated with these alleles influences the evolutionary divergence of the HIV-1 genome, sequencing of the envelope V3 loop was performed. This revealed a significantly diminished lymphocyte viral heterogeneity compared with random HIV+ controls matched for CD4 T-cell levels. These results suggest that the immunogenetics of the host influence the nature of the immune response to HIV-1, which may lead to constrained evolution of HIV-1 gene products. Of possible relevance, the alpha-helical third diversity region common to both the DRB1*1102 and DRB1*1301 allelic products was noted to have homology with the C-terminal region of the HIV-1 envelope V3 loop at six of nine consecutive residues. This suggests the possibility that these alleles may bias the anti-HIV T-cell receptor repertoire through a mimicry mechanism.