Evaluation of the reliability and validity of the Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI) in paediatric cutaneous lupus among paediatric dermatologists and rheumatologists.

BACKGROUND: The Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI) is a reliable outcome measure for cutaneous lupus erythematosus (CLE) in adults used in clinical trials. However, it has not been validated in children, limiting clinical trials for paediatric CLE. OBJECTIVES: This study aimed to validate the CLASI in paediatrics. METHODS: Eleven paediatric patients with CLE, six dermatologists and six rheumatologists participated. The physicians were trained to use the CLASI and Physician's Global Assessment (PGA), and individually rated all patients using both tools. Each physician reassessed two randomly selected patients. Within each physician group, the intraclass correlation coefficient (ICC) was calculated to assess the reliability of each measure. RESULTS: CLASI activity scores demonstrated excellent inter- and intrarater reliability (ICC > 0·90), while the PGA activity scores had good inter-rater reliability (ICC 0·73-0·77) among both specialties. PGA activity scores showed excellent (ICC 0·89) and good intrarater reliability (ICC 0·76) for dermatologists and rheumatologists, respectively. Limitations of this study include the small sample size of patients and potential recall bias during the physician rerating session. CONCLUSIONS: CLASI activity measurement showed excellent inter- and intrarater reliability in paediatric CLE and superiority over the PGA. These results demonstrate that the CLASI is a reliable and valid outcome instrument for paediatric CLE.

Child-onset systemic lupus erythematosus is associated with a higher incidence of myopericardial manifestations compared to adult-onset disease.

OBJECTIVES: There are no population-based estimates of the incidence or risk factors for acute cardiac manifestations in children with systemic lupus erythematosus (SLE) to guide screening and diagnostic imaging practices. We estimated the incidence and prevalence of acute cardiac manifestations of child-onset SLE compared to adult-onset SLE and identified factors associated with cardiac diagnoses. METHODS: We identified children (5-17 years) and adults (18-64 years) with incident SLE (≥3 International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9 CM) code 710.0, > 30 days apart) using Clinformatics® DataMart (OptumInsight, Eden Prairie, MN) deidentified United States administrative claims (2000-2013). We calculated incidence and prevalence of three outcomes: ≥ 1 diagnosis code for (1) pericarditis and/or myocarditis, (2) endocarditis, or (3) valvular insufficiency. Negative binomial regression was used to identify characteristics associated with cardiac diagnoses in children and determine whether SLE onset in childhood vs adulthood was independently associated with cardiac involvement. RESULTS: There were 297 children and 6927 adults with new-onset SLE. A total of 17.8% of children had ICD-9 CM codes for acute cardiac diagnoses, the incidence of which were highest in the first year after SLE diagnosis (12.2 per 100 person-years). African American race (incidence rate ratio (IRR) 6.6, 95% confidence interval (CI) (2.9, 15.0), p < 0.01) and nephritis (IRR 7.0, 95% CI (2.6, 18.6), p < 0.01) were associated with acute cardiac diagnoses in children. Child-onset disease was independently associated with a 4.4-fold higher rate of pericarditis or myocarditis compared to adult-onset SLE after adjustment for other disease and demographic characteristics (95% CI (2.4, 8.0), p < 0.01). CONCLUSION: This study establishes baseline estimates of the incidence and prevalence of pericarditis and myocarditis in child-onset SLE, which is substantially higher than that of adult-onset SLE. Prospective echocardiographic evaluations are needed to validate incidence measures and characterize the natural history of acute cardiac manifestations in child-onset SLE, as well as identify risk factors for poor cardiac outcomes to inform screening and management.

Use of echocardiography at diagnosis and detection of acute cardiac disease in youth with systemic lupus erythematosus.

Objectives There are no guidelines on the use of echocardiography to detect cardiac manifestations of childhood-onset systemic lupus erythematosus (SLE). We quantify the prevalence of acute cardiac disease in youth with SLE, describe echocardiogram utilization at SLE diagnosis, and compare regional echocardiogram use with incident cardiac diagnoses. Methods Using the Clinformatics® DataMart (OptumInsight, Eden Prairie, MN) de-identified United States administrative database from 2000 to 2013, we identified youth ages 5-24 years with new-onset SLE (≥3 ICD-9 SLE codes 710.0, > 30 days apart) and determined the prevalence of diagnostic codes for pericardial disease, myocarditis, endocarditis, and valvular insufficiency. Multiple logistic regression was used to identify factors associated with echocardiography during the baseline period, up to one year before or six months after SLE diagnosis. We calculated a regional echocardiogram utilization index, which is the ratio of observed use over the mean predicted probability based on all available baseline characteristics. Spearman's rank correlation coefficient was used to evaluate the association between regional echocardiogram utilization indices and percentage of imaged youth diagnosed with their first cardiac manifestation following echocardiography. Results Among 699 youth with new-onset SLE, 18% had ≥ 1 diagnosis code for acute cardiac disease, of which valvular insufficiency and pericarditis were most common. Twenty-five percent of all youth underwent echocardiogram during the baseline period. Regional echocardiogram use was positively correlated with the percentage of imaged youth found to have cardiac disease (ρ = 0.71, p = 0.05). There was up to a five-fold difference in adjusted odds of baseline echocardiography between low- and high-utilizing regions (OR = 0.19, p = 0.007). Conclusion Nearly one-fifth of youth with new-onset SLE have acute cardiac manifestations; however, use of echocardiograms at SLE diagnosis is highly variable. There may be incremental diagnostic value to early use of echocardiography, but prospective studies are needed to determine whether greater use of echocardiograms modifies outcomes.

Distinct intracellular compartments involved in invariant chain degradation and antigenic peptide loading of major histocompatibility complex (MHC) class II molecules.

Major histocompatibility complex (MHC) class II molecules are transported to intracellular MHC class II compartments via a transient association with the invariant chain (Ii). After removal of the invariant chain, peptides can be loaded onto class II molecules, a process catalyzed by human leukocyte antigen-DM (HLA-DM) molecules. Here we show that MHC class II compartments consist of two physically and functionally distinct organelles. Newly synthesized MHC class II/Ii complexes were targeted to endocytic organelles lacking HLA-DM molecules, where Ii degradation occurred. From these organelles, class II molecules were transported to a distinct organelle containing HLA-DM, in which peptides were loaded onto class II molecules. This latter organelle was not directly accessible via fluid phase endocytosis, suggesting that it is not part of the endosomal pathway. Uptake via antigen-specific membrane immunoglobulin resulted however in small amounts of antigen in the HLA-DM positive organelles. From this peptide-loading compartment, class II-peptide complexes were transported to the plasma membrane, in part after transit through endocytic organelles. The existence of two separate compartments, one involved in Ii removal and the other functioning in HLA-DM-dependent peptide loading of class II molecules, may contribute to the efficiency of antigen presentation by the selective recruitment of peptide-receptive MHC class II molecules and HLA-DM to the same subcellular location.

An RGD-oligolysine peptide: a prototype construct for integrin-mediated gene delivery.

We have synthesized a linear, bifunctional peptide that comprises an integrin-targeting domain containing an arginine-glycine-aspartic acid tripeptide motif and a DNA-binding moiety consisting of a short stretch of 16 lysine residues. This peptide can form distinctive, condensed complexes with DNA and is capable of mediating its delivery and expression in a variety of mammalian cells in culture. Internalization is mediated by cell surface integrin receptors via a mechanism that is known to be phagocytic. We have analyzed the relationship between DNA and peptide and have investigated the conditions suitable for optimal gene delivery. The formation of condensed peptide DNA complexes leads to resistance to nuclease degradation. The level of reporter gene expression obtained is dependent on the peptide-to-DNA ratio and is enhanced in the presence of the endosomal buffer chloroquine, polyethyleneimine, and deactivated adenovirus during gene delivery. Under optimal conditions the levels of reporter gene expression obtained approach or even exceed those obtained with DNA delivered with the commercial liposome Lipofectamine. The ability to produce an efficient gene delivery system using small, easily modified, and well-defined constructs that have no constraint of particle size demonstrates the advantages of integrin-targeting peptides for gene transfer.

Lipid-mediated enhancement of transfection by a nonviral integrin-targeting vector.

Nonviral vectors consisting of integrin-targeting peptide/DNA (ID) complexes have the potential for widespread application in gene therapy. The transfection efficiency of this vector, however, has been limited by endosomal degradation. We now report that lipofectin (L) incorporated into the ID complexes enhances integrin-mediated transfection, increasing luciferase expression by more than 100-fold. The transfection efficiency of Lipofectin/Integrin-binding peptide/DNA (LID) complexes, assessed by beta-galactosidase reporter gene expression and X-gal staining, was improved from 1% to 10% to over 50% for three different cell lines, and from 0% to approximately 25% in corneal endothelium in vitro. Transfection complexes have been optimized with respect to their transfection efficiency and we have investigated their structure, function, and mode of transfection. Both ID and LID complexes formed particles, unlike the fibrous network formed by lipofectin/DNA complexes (LD). Integrin-mediated transfection by LID complexes was demonstrated by the substantially lower transfection efficiency of LKD complexes in which the integrin-biding peptide was substituted for K16 (K). Furthermore, the transfection efficiency of complexes was shown to be dependent on the amount of integrin-targeting ligand in the complex. Finally, a 34% reduction in integrin-mediated transfection efficiency by LID complexes was achieved with a competing monoclonal antibody. The role of lipofectin in LID complexes appears, therefore, to be that of a co-factor, enhancing the efficiency of integrin-mediated transfection. The mechanism of enhancement is likely to involve a reduction in the extent of endosomal degradation of DNA.

Monoclonal antibodies from Epstein-Barr virus-transformed lymphocytes of common marmosets (Callithrix jacchus) immune to malaria.

The B lymphocytes of the common marmoset Callithrix jacchus can be immortalized by infection with Epstein-Barr virus (EBV) in vitro (Desgranges et al., 1976). C. jacchus is susceptible to infection with the blood stages of several species of malaria parasite including the line designated MVF1 (Mitchell et al., 1988) from which it recovers and shows immunity to reinfection. By exploiting these two phenomena, EBV-transformed, marmoset lymphoblastoid cell lines secreting antibodies to malaria parasite antigens have been generated and cloned. We believe this to be the first time that monoclonal antibodies (MAbs) have been raised from common marmosets. Since numerous and diverse human pathogens can infect this small primate in the laboratory, these methods may prove generally applicable for the generation of MAbs whose specificities derive from immune responses to infection.

Endogenous ligands selecting T cells expressing particular V beta elements.

It has recently become clear that the minor lymphocyte stimulatory antigens (Mls) and other endogenous ligands which lead to the partial or total deletion of T cells bearing particular V beta segments are encoded by mouse mammary tumor virus (MMTV). We review here the genetic analyses of multiple V beta 11 and V beta 3 deletion ligands and demonstrate the involvement of MMTV in all examples. Several features of Mls and the V beta 11/V beta 3 deleting ligands identify them as members of the superantigen family. Bacterial superantigens are known to bind both MHC class II and the TCR in regions distinct from conventional peptide antigens. Within the MMTV genome, the 3' LTR has been identified as encoding superantigen function. We present data demonstrating that in vitro translation identifies the major product of the open reading frame (ORF) within the 3' LTR as a type II integral membrane glycoprotein. It is proposed that the type II membrane glycoprotein interacts with MHC and TCR in a manner analogous to the bacterial superantigens and distinct from conventional peptide antigen. Several unanswered questions regarding superantigen action remain; what determines total or partial deletion? How is Mls transferred between cells? These questions are addressed in the discussion.

Consistency of voice produced by patients with adductor spasmodic dysphonia: a preliminary investigation.

Adductor spasmodic dysphonia (ADSD) is an idiopathic focal laryngeal movement disorder causing involuntary and uncontrollable spasms in the vocal fold musculature, primarily during voice onset. Although phonatory instability has been reported through clinical observation and empirical study, no examination of phonatory performance consistency in ADSD has been done. Phonatory instability refers to phonatory unsteadiness and has been previously defined by the presence of acoustic aberrations during speech. Performance consistency pertains to variations in these phonatory aberrations across repeated trials or over time. This study focused on the phonatory performance consistency of those with ADSD by using three acoustic measures of phonatory instability. Twenty patients with ADSD were recorded during three trials of reading a standard passage. Eight of the 20 patients were recorded twice during two separate recording sessions held approximately 6 months apart. The number of phonatory breaks, frequency shifts, and aperiodic segments were the dependent measures. Data were subjected to inferential statistical analysis to test for significant differences among the measures in two conditions: across three trials produced within one recording session and across multiple trials produced during two distinct recording sessions. No significant differences were found for any of the measures either as a function of trials recorded on the same day or across the two recording sessions. The data suggest a need for describing phonatory instability and performance consistency as separate entities with regard to neurological voice disorders.

Detection of DNA polymorphisms between two inbred mouse strains--limitations of restriction fragment length polymorphisms (RFLPs).

Type I (insulin-dependent) diabetes in humans is characterized by a T cell mediated destruction of insulin-secreting pancreatic beta cells. This autoimmune response is very similar to that seen in the non-obese diabetic (NOD) mouse strain. Originally bred from the ICR cataract-prone strain, NOD mice spontaneously develop T cell mediated insulitis and type I diabetes by the age of 6 months. Backcross studies with the NOD mouse strain indicate segregation of at least three recessive genes. One of these, Iddm-1, has been shown to be tightly linked to the mouse MHC, H-2 on chromosome 17. Comparative studies with diabetic patients has also shown linkage to human HLA with protective and predisposing haplotypes being present within the population. In this study we have attempted to identify restriction fragment length polymorphisms (RFLPs) between the genomes of the NOD mouse strain and the diabetes-resistant strain C57BL/10. Such polymorphic loci will be used to screen DNAs from backcross animals that are diagnosed diabetic in an attempt to identify probes linked to the non-H2 disease susceptibility genes.

I-E-independent deletion of V beta 17a+ T cells by Mtv-3 from the nonobese diabetic mouse.

Analysis of TCR beta-chain V region (V beta) frequency among NOD lymphocytes reveals a profound depletion of V beta 3+ T cells, and a recent study has linked this phenomenon to the Mtv-3 insertion on chromosome 11. When the V beta 17a gene segment is introduced into mice with an nonobese diabetic mouse background, T cells bearing the TCR encoded by this gene segment are also dramatically reduced in frequency. Deletion of V beta 17a+ T cells segregates with deletion of T cells bearing V beta 3 and occurs in the absence of I-E, which had been shown in previous studies to be a major deleting element for V beta 17a+ thymocytes.

PCR-analyzed microsatellites of the mouse genome--additional polymorphisms among ten inbred mouse strains.

Eighty sequences from the mouse genome database containing microsatellites (simple sequence repeats) have been analyzed for size variation among ten different inbred strains of mice; 62/80 (77.5%) showed polymorphism of at least three alleles. We have been able to detect all the polymorphisms by agarose gel electrophoresis, often running the gels for up to 3 h. Between individual pairs of mouse strains to be used in chromosomal mapping studies in our laboratory, 35-60% polymorphism occurred. There are potentially enough microsatellites within the mouse and human genome to have a marker at every 1-cM distance. This simple approach will, therefore, continue to be useful in genome mapping studies, leading eventually to high-resolution maps of both the mouse and human genomes; this should allow for physical mapping and cloning of specific genes.

Plasmodium vivax malaria in the common marmoset, Callithrix jacchus: adaptation and host response to infection.

Infection with Plasmodium vivax was established in splenectomized Callithrix jacchus marmosets by inoculation of parasitized blood from Aotus trivirgatus carrying the Vietnam Palo-Alto line of P. vivax. Subsequent blood passage through intact marmosets resulted in higher peak parasitaemias (about 1% of red cells infected) and the loss of stainable Schüffner's dots in infected cells. Primary infections with the adapted line were patent for 74 days or more, and induced both a substantial antibody response, as determined by indirect fluorescence, and some lymphocytosis, but no marked anaemia. Marmosets which had recovered from their primary infection (or in which it was drug-cured) suffered abbreviated patency with low-grade parasitaemia on re-infection.

Antigen endocytosis and presentation mediated by human membrane IgG1 in the absence of the Ig(alpha)/Ig(beta) dimer.

Membrane immunoglobulin (mIg) M and D heavy chains possess minimal (KVK) cytoplasmic tails and associate with the Ig alpha/Ig beta (CD79) dimer to achieve surface expression and antigen presentation function. In contrast, the cytoplasmic tail of mIgG is extended by 25 residues (gamma ct). We have tested the possibility that mIgG can perform antigen capture and presentation functions independently of the Ig(alpha)/beta dimer. We show that CD4/(gamma)ct chimeras are efficiently endocytosed partially dependent on a tyrosine residue in (gamma)ct. In addition, human mIgG was expressed on the surface of Ig(alpha)/Ig(beta)-negative non-lymphoid cells and mediated antigen capture and endocytosis. Antigen-specific human mIgG targeted antigen to MIIC-type vesicles in the Ig(alpha)/beta negative melanoma Mel JuSo and augmented antigen presentation 1000-fold, identical to the augmentation seen in Ig(alpha)/beta-positive B-cells expressing the same transfected mIgG. Thus, unlike mIgM, mIgG has autonomous antigen capture and presentation capacity, which may have evolved to reduce or eliminate the BCR's dependence on additional accessory molecules.

Towards construction of a high resolution map of the mouse genome using PCR-analysed microsatellites.

Fifty sequences from the mouse genome database containing simple sequence repeats or microsatellites have been analysed for size variation using the polymerase chain reaction and gel electrophoresis. 88% of the sequences, most of which contain the dinucleotide repeat, CA/GT, showed size variations between different inbred strains of mice and the wild mouse, Mus spretus. 62% of sequences had 3 or more alleles. GA/CT and AT/TA-containing sequences were also variable. About half of these size variants were detectable by agarose gel electrophoresis. This simple approach is extremely useful in linkage and genome mapping studies and will facilitate construction of high resolution maps of both the mouse and human genomes.

Co-segregation of a gene encoding a deletion ligand for Tcrb-V3+ T cells with Mtv-3.

A gene encoding the endogenous superantigen Mlsc, which deletes Tcrb-V3+ T cells in the NOD inbred mouse strain, was found to co-segregate with Mtv-3 on chromosome 11. This identifies a fourth gene encoding a deletion ligand for Tcrb-V3+ T cells and extends recently published observations in support of the hypothesis that a number of endogenous superantigens are the products of Mtv proviruses.

Genes encoding ligands for deletion of V beta 11 T cells cosegregate with mammary tumour virus genomes.

The T-cell receptor (TCR) repertoire is selected in the thymus after rearrangement of genes encoding TCR alpha and beta chains. Selection is based on the recognition by newly emergent T cells of self-ligands associated with molecules of the major histocompatibility complex: some combinations result in positive selection, others in negative selection. Negative selection, or clonal deletion, is an important mechanism for eliminating autoreactive T cells. A group of self-ligands involved in clonal deletion was identified because they, like exogenous superantigens, were recognized by almost all T cells expressing particular TCR V beta genes. V beta 17a T cells are deleted by a tissue-specific ligand; V beta 6, V beta 7, V beta 8.1 and V beta 9 T cells are deleted by the minor lymphocyte-stimulating (Mls) determinant Mls-1a; V beta 3 T cells by Mls-2a and Mls-3a; V beta 11 T cells by ligands encoded by independently segregating genes; and V beta 5 T cells by ligands encoded by two genes. Chromosome mapping using recombinant inbred strains of mice and classic backcrosses show that Mls-1a in DBA/2 mice is encoded on chromosome 1, that one of the two ligand genes for deletion of V beta 5 T cells maps to chromosome 12 and that a ligand gene for V beta 11 deletion is linked to the CD8 locus on chromosome 6. Here we present evidence from three sets of backcross mice for concordance between V beta 11 deletion ligand genes on chromosomes 6, 12 and 14 and endogenous mouse mammary tumour virus integrant (Mtv) genomes.(ABSTRACT TRUNCATED AT 250 WORDS)

Mapping of the genes encoding tum- transplantation antigens P91A, P35B, and P198.

Tum- comprises a class of genes, mutation of which in P815 tumor cells has led to the acquisition of new cytotoxic T cell-recognized epitopes. The cells carrying the mutant alleles have impaired tumorigenicity compared with their progenitors due to in vivo induction of a cytotoxic T-cell response specific for tum- antigens. Two tum- genes, P91A and P35B, were found to be single copy loci mapping to chromosomes 11 and 15 respectively. A third, P198, was found to map to chromosome 7 and to be a member of a small gene family with other members on chromosomes 13, 14, and 15. Multiple P198-related sequences were found in other mammalian species suggesting the P198 related gene family is a general feature of mammalian genomes.

Biochemical analysis of the mouse mammary tumor virus long terminal repeat product. Evidence for the molecular structure of an endogenous superantigen.

Recent reports have shown that both exogenous and endogenous mouse mammary tumor viruses (MMTV) can encode superantigens. Transfection and transgenic studies have identified the open reading frame (ORF) present in the 3' long terminal repeat (LTR) as encoding superantigen function. In this study, we have used an in vitro translation system in an attempt to characterize the molecular nature of the protein encoded by the 3' ORF of Mtv-8. Using various constructs encoding full-length and truncated versions of the ORF product, we report that the hydrophobic region close to the amino terminus of the 36-kDa protein can function as a transmembrane domain. Protease digestion experiments also demonstrate that the protein has a type-II transmembrane conformation with an extra-cytoplasmic carboxy terminus. Since this hydrophobic region is conserved between all known MMTV, we speculate that LTR ORF, including those proposed to encode the minor lymphocyte stimulatory antigens, are also capable of encoding type-II transmembrane glycoproteins. The polymorphism between MMTV LTR ORF products, which correlates with deletion phenotypes, is predominantly in the carboxy-terminal extracellular region, consistent with a major role in interaction with the T cell receptor.

Vaccination trials in rhesus monkeys with a minor, invariant, Plasmodium knowlesi 66 kD merozoite antigen.

A minor Plasmodium knowlesi 66 kD antigen, which plays an essential role in merozoite invasion, has been shown to be stable in distinct variants and strains of the parasite, and in the face of a specific immune response from the host. Parasites were unable to produce novel molecule(s) to replace it functionally, even in the presence of specific immune pressure. Rhesus monkeys immunized with the purified 66 kD antigen, with saponin as adjuvant, produced antibody which inhibited merozoite invasion of red cells in vitro. Four out of six immunized rhesus monkeys demonstrated clinically effective immunity when challenged at a time of known or presumed high inhibitory antibody titre. When immunization failed to protect, it was ascribed to insufficient levels of specific antibody attributable either to a suboptimal dose of antigen or the use of an inadequate adjuvant.