HLA and amyotrophic lateral sclerosis: a systematic review and meta-analysis.

Background: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease associated with loss of upper and lower motor neurones. It leads to death by respiratory failure and has a typical prognosis of 2-3 years. The immune system has been shown to play a role in the pathophysiology of ALS. Some of the most important immune genes are within the human leukocyte antigen (HLA) region, and a recent genome-wide association study (GWAS) has identified a risk allele for ALS within the HLA region. Older studies have also suggested an HLA association with ALS, with certain HLA alleles showing differing expression between patients and controls. This systematic review and meta-analysis examines the previous studies performed in this field.Methods: We used established publication search engines. Findings were excluded if they did not meet the selection criteria. We then undertook statistical meta-analysis on the eligible papers, using a fixed effects model.Results: There were eight eligible papers. There were three statistically significant meta-analysis findings, although these would not be significant after correction for multiple comparisons. The frequencies of HLA-A9 and HLA-DR4 genotypes were lower in ALS subjects than controls, and HLA-B35 was higher in ALS subjects.Discussion: This systematic review and meta-analysis do not confirm all the previously reported associations of HLA with ALS, but shows three alleles of interest. However, there are limitations to the studies, which include the use of older serotyping methodology and the small numbers of subjects. Given the recent GWAS association with HLA, further modern HLA studies are warranted.

Perceptions of autism spectrum disorder among the Swahili community on the Kenyan coast.

BACKGROUND: In high-income and Western societies there is great understanding and awareness of autism spectrum disorder (ASD); however, for many low-middle income countries, research and knowledge is notably lacking. In Africa, there is a growing prevalence of ASD due to increased diagnosis, yet it is still a poorly understood condition. AIMS: Emerging literature has emphasised how cultural and societal beliefs underpin the level of understanding of ASD, and which typically results in lack of awareness and acceptance. As such it is important to investigate the cultural perceptions towards ASD within low-middle income communities of African culture, to further understand the challenges and barriers individuals with ASD face. The aim of the current study was to probe participants from the Swahili community, on the coast of Kenya, of their cultural views towards ASD. METHOD: Semi-structured interviews were conducted with seven participants, and the data analysed using thematic analysis. RESULTS: Three key themes developed from the data; stigma, lack of awareness, and Government responsibility. CONCLUSION: Cultural perceptions negatively impacted awareness and are exacerbated by lack of directive from the Government in providing appropriate diagnostic and educational support.

Evaluation of RIDA®GENE norovirus GI/GII real time RT-PCR using stool specimens collected from children and adults with acute gastroenteritis.

BACKGROUND: Norovirus is the leading cause of epidemic and sporadic acute gastroenteritis (AGE) in the United States. Widespread prevalence necessitates implementation of accurate norovirus detection assays in clinical diagnostic laboratories. OBJECTIVE: To evaluate RIDA®GENE norovirus GI/GII real-time RT-PCR assay (RGN RT-PCR) using stool samples from patients with sporadic AGE. STUDY DESIGN: Patients between 14 days to 101 years of age with symptoms of AGE were enrolled prospectively at four sites across the United States during 2014-2015. Stool specimens were screened for the presence of norovirus RNA by the RGN RT-PCR assay. Results were compared with a reference method that included conventional RT-PCR and sequencing of a partial region of the 5'end of the norovirus ORF2 gene. RESULTS: A total of 259 (36.0%) of 719 specimens tested positive for norovirus by the reference method. The RGN RT-PCR assay detected norovirus in 244 (94%) of these 259 norovirus positive specimens. The sensitivity and specificity (95% confidence interval) of the RGN RT-PCR assay for detecting norovirus genogroup (G) I was 82.8% (63.5-93.5) and 99.1% (98.0-99.6) and for GII was 94.8% (90.8-97.2) and 98.6% (96.9-99.4), respectively. Seven specimens tested positive by the RGN-RT PCR that were negative by the reference method. The fifteen false negative samples were typed as GII.4 Sydney, GII.13, GI.3, GI.5, GI.2, GII.1, and GII.3 in the reference method. CONCLUSIONS: The RGN RT-PCR assay had a high sensitivity and specificity for the detection of norovirus in stool specimens from patients with sporadic AGE.

Levels of phosphorylated axonal neurofilament subunit H (pNfH) are increased in acute ischemic stroke.

For the study of stroke outcomes, there is the need for measurements of severity of stroke damage. Phosphorylated neurofilament heavy protein (pNfH) levels are elevated in axonal injury. We have measured levels of pNfH in stroke and correlated these levels with measures of stroke severity. Blood samples were collected from 54 ischaemic stroke patients at day 1, week 1 (days 7-10) and weeks 3-6, and an ELISA was used to measure pNfH levels in each patient at each time-point. Serum pNfH levels were significantly elevated in stroke patients compared to healthy controls. The levels were low at day 1, higher at day 7 and reached a peak at week 3, the latest day that we assessed. Significant associations were found between the pNfH levels at week 3 and early and stroke severity, size and outcome. Blood pNfH levels that reflect the severity of ischaemic stroke, are correlated with outcome and rise during the weeks after stroke. This may be a useful measure of tissue damage in stroke.

Sexual dimorphism in autoimmune disease.

We briefly survey the concept of autoimmunity and nominate the range of autoimmune diseases that include multisystemic and organ-specific disorders, and cite prevalences of autoimmune diseases in males and females, in humans and in experimental animals. Most human autoimmune diseases such as systemic lupus erythematosus (SLE), multiple sclerosis (MS) and autoimmune thyroid disease, have an increased incidence and prevalence in females, but a few others such as autoimmune diabetes, the Guillain Barré syndrome (GBS) and psoriasis are increased in males. Animal models of autoimmunity show an equivalent sexual dimorphism. The possible reasons for the differing incidence and prevalence of autoimmune diseases in females and males engage our attention. Environmental exposures may differ for females and males. There are innate differences in the function of the female and male immune systems, and there is some evidence for differences between females and males in the ability of a target organ for autoimmunity to withstand damage. In seeking reasons for these differences, we review the role of sex hormones in immunity and include results of trials of hormone therapy in autoimmune diseases. The association of autoimmunity and pregnancy, a female-specific condition, is discussed, and the claimed effects of lymphoid cell microchimerism on provocation of autoimmunity are reviewed. Genetic predisposition is an important factor in autoimmune disease and we particularly focus on genes on the X and Y chromosomes, the role of X chromosome inactivation, and the interaction of the sex of the patient with other genetic factors. The possible role of epigenetic mechanisms, including environmental influences, is then surveyed. We assert that sex is a vital variable that must be considered in all immunological studies, as it should be at all levels of biological research.

Prominent brainstem and cerebellar involvement in multiple sclerosis with psoriasis.

INTRODUCTION: We identified a subgroup of 20 patients with multiple sclerosis (MS) and psoriasis within a total group of 692 patients with MS. RESULTS: There was a high (80%) incidence of brainstem and/or cerebellar involvement and a high mean (+/-SD) Multiple Sclerosis Severity Score (6.06 +/- 2.88) in this subgroup. Of the patients who were human leukocyte antigen typed, 53% carried the MS-associated allele, DRB1*1501, and 27% carried the psoriasis-associated DRB1*07 allele. CONCLUSION: The high incidence of brainstem and cerebellar involvement might be explained by the greater severity of MS and the high frequency (60%) of carriage of DRB1*04, DRB1*07, and/or DRB1*13 alleles, which are associated with brainstem and cerebellar involvement in MS.

NF-kappa B, a potential therapeutic target for the treatment of multiple sclerosis.

Multiple sclerosis (MS) is a chronic inflammatory autoimmune disease of the central nervous system (CNS) that afflicts over 2 million people worldwide. On the basis of the temporal course of disease, MS can be subdivided into three clinical groups: relapsing remitting MS (RR-MS), secondary progressive MS and primary progressive MS. There is a high degree of clinical diversity within these subgroups. The pathogenesis of MS in most patients is likely to result from autoreactive, activated CD4(+) T cells moving from the periphery across the blood brain barrier into the CNS. Most therapeutic agents used in MS (e.g. immunosuppressive and immunomodulatory drugs and cell cycle interruption drugs) are only used for RR-MS. These treatments show some efficiency in lessening the relapse rate in RR-MS and time to progression, but cannot cure MS. Thus, there is a need for new efficient treatments for all types of MS. An increasing number of studies indicate that nuclear factor-kappaB plays an important role in controlling expression of genes relevant to the pathogenesis of autoimmunity. Genetic factors related to NF-kappaB may also be determinants of MS susceptibility, as polymorphisms in the molecules involved in regulation of the NF-kappaB signal transduction pathway differ between RR-MS and progressive MS. Herein, the role of NF-kappaB in MS will be reviewed and its potential as a new therapeutic target in MS will be considered and compared with existing treatments.

The presence of glutamic acid at positions 71 or 74 in pocket 4 of the HLA-DRbeta1 chain is associated with the clinical course of multiple sclerosis.

BACKGROUND: Primary progressive multiple sclerosis (PP-MS) differs from relapsing-remitting or secondary progressive MS (RR/SP-MS) in ways suggesting differences in the pathogenic pathways. Susceptibility to both PP-MS and RR/SP-MS is linked to carriage of the HLA molecule DRB1*1501. Several serologically defined HLA-DR groups (DR1, DR4, DR6, and DR9) occur less often in RR/SP-MS than in controls. Some or all of the HLA-DR molecules encoded by alleles in these serologically defined groups have a negatively charged glutamic acid at residue 71 or 74 of the beta1 chain (beta1(71)/beta1(74)). Residues at these positions are important in the formation of pocket 4 in the antigen binding site of the HLA-DR molecule. OBJECTIVES: To investigate whether the presence of alleles encoding HLA-DR molecules containing glutamic acid at beta1(71)/beta1(74) correlates with the course of MS. METHODS: HLA-DR and HLA-DQ alleles and genotypes were analysed in 121 MS patients (50 with PP-MS) and 109 controls by molecular typing. RESULTS: Alleles encoding HLA-DR molecules containing a glutamic acid at beta1(71)/beta1(74) occurred less often in patients with RR/SP-MS than in those with PP-MS or controls. In subjects not carrying the DRB1*1501 allele, a much higher proportion of PP-MS patients carried alleles encoding HLA-DR molecules containing a glutamic acid at beta1(71)/beta1(74) than did RR/SP-MS patients or controls. CONCLUSIONS: The amino acid residues involved in determining the shape and charge of pocket 4 of the HLA-DR beta1 chain could influence the clinical course of MS by determining protection against RR/SP-MS or susceptibility to the development of PP-MS.

Comparison of hepatitis C viral loads in patients with or without human immunodeficiency virus.

A better understanding of how human immunodeficiency virus (HIV) coinfection affects the course of hepatitis C virus (HCV) infection is required to select patients with HIV who would benefit from current HCV therapy. Between June 1996 and March 2000, HCV RNA levels were quantified for 1,279 patients at the Louisiana State University Health Sciences Center; 28 of these patients were coinfected with HIV. HCV loads were quantified by the Bayer branched-DNA assay with a lower limit of detection of 0.2 Meq/ml. We compared the median HCV RNA levels of for patients coinfected with HIV and HCV and patients infected only with HCV who were in the same age range (23 to 55 years). The median HCV load for the 28 patients coinfected with HCV and HIV (17.8 Meq/ml) was significantly greater (P < 0.05) than that for similarly aged patients infected only with HCV (6.1 Meq/ml). The HCV load did not correlate with age or sex for either group of patients. A significant (R = -0.4; P < 0.05) negative correlation was observed between HCV load and CD4 count in the coinfected group, for whom the CD4 counts at the time of HCV load analysis ranged from 6 to 1,773/mm(3). The increased HCV load in patients coinfected with HCV and HIV compared to that in patients infected only with HCV and the inverse relationship of the HCV load to the CD4 count indicate that immunosuppression results in decreased control of HCV replication. In addition, we report significantly higher HCV loads among coinfected African Americans than Caucasians.

Thiopalmitoylation of myelin proteolipid protein epitopes enhances immunogenicity and encephalitogenicity.

Proteolipid protein (PLP) is the most abundant protein of CNS myelin, and is posttranslationally acylated by covalent attachment of long chain fatty acids to cysteine residues via a thioester linkage. Two of the acylation sites are within epitopes of PLP that are encephalitogenic in SJL/J mice (PLP(104-117) and PLP(139-151)) and against which increased immune responses have been detected in some multiple sclerosis patients. It is known that attachment of certain types of lipid side chains to peptides can result in their enhanced immunogenicity. The aim of this study was to determine whether thioacylated PLP peptides, as occur in the native protein, are more immunogenic than their nonacylated counterparts, and whether thioacylation influences the development of autoreactivity and experimental autoimmune encephalomyelitis. The results show that in comparison with nonacylated peptides, thioacylated PLP lipopeptides can induce greater T cell and Ab responses to both the acylated and nonacylated peptides. They also enhanced the development and chronicity of experimental autoimmune encephalomyelitis. Synthetic peptides in which the fatty acid was attached via an amide linkage at the N terminus were not encephalitogenic, and they induced greater proportions of CD8+ cells in initial in vitro stimulation. Therefore, the lability and the site of the linkage between the peptide and fatty acid may be important for induction of encephalitogenic CD4+ T cells. These results suggest that immune responses induced by endogenous thioacylated lipopeptides may contribute to the immunopathogenesis of chronic experimental demyelinating diseases and multiple sclerosis.

Validation of the Roche COBAS Amplicor system for Chlamydia trachomatis.

OBJECTIVE: Validation of the Roche Amplicor polymerase chain reaction (PCR) using the Comprehensive Bio-Analytical System (COBAS) automated PCR analyzer in our laboratory. DESIGN: Endocervical swab specimens for both EIA and PCR were collected from a total of 193 women. EIA for chlamydia was performed using the MicroTrak Chlamydia Kit (Wampole Labs, Cranbury, NJ). PCR was performed using Roche Amplicor reagents on the COBAS instrument. SETTING: Louisiana State University Health Sciences Center at Shreveport, Shreveport LA. PATIENTS: All cervical swab specimens, (n = 193), collected from patients presenting either to the Women's Health or Primary Care Clinic (Obstetrics and Gynecology and Family Practice) were included in this study. RESULTS: Most of the specimens, 138/193 or 71.5%, tested negative by both techniques. Three of the 193 specimens, 1.5%, were inhibitory for PCR since the internal control was negative. Fifty-one specimens, 26.4%, tested positive by both techniques or by PCR alone. No specimens were positive by EIA only. Twenty-eight of the 51 were positive by both methods, (14.5% of the total tested; 54.9% agreement among the specimens testing positive). An additional 23 were positive by PCR alone, i.e., 11.9% total discrepant positive specimens; 45% discordant results among the specimens testing positive). Seventeen PCR-positive specimens divided among four separate runs were retested by PCR. Of these, 15 were repeat positive, giving the test a reproducibility of 88.2%. CONCLUSIONS: Our results concur with previously published comparison data for EIA and PCR testing. We conclude that the PCR should detect a significantly increased number of chlamydia infections among our LSUHSC-S population, but there are drawbacks to using this technique. Specimen preparation time for PCR is almost twice as long as EIA, and the Roche PCR assay is not licensed for ocular specimens as is our EIA procedure. In addition, since neither technique is accepted for testing for medicolegal purposes, we must continue the use of culture for cases of suspected sexual abuse.

Early pregnancy factor suppresses experimental autoimmune encephalomyelitis induced in Lewis rats with myelin basic protein and in SJL/J mice with myelin proteolipid protein peptide 139-151.

Early pregnancy factor (EPF) is a secreted protein with immunosuppressive and growth factor properties. During pregnancy, it appears in maternal serum within 6-24 h of fertilization, is present for at least the first two-thirds of pregnancy in all species studied and is essential for embryonic survival. It is a homologue of chaperonin 10, a heat shock protein, but, unlike other members of this family, EPF has an extracellular role. As it has the ability to modulate CD4+ T cell-dependent immune responses, its role in treatment of experimental autoimmune encephalomyelitis (EAE) was investigated. EAE is a CD4+ T cell-mediated disease, the best available animal model of multiple sclerosis (MS). Two models of EAE were investigated, acute EAE induced in Lewis rats by inoculation with myelin basic protein (MBP-EAE) and chronic relapsing EAE induced in SJL/J mice by inoculation with myelin proteolipid protein peptide (residues 139-151) (PLP-EAE). EPF, delivered intraperitoneally or orally to rats or intraperitoneally to mice, suppressed clinical signs of disease. Mice with PLP-EAE were also treated with interferon-beta, with and without EPF. Both EPF and IFN-beta suppressed clinical signs of EAE and, when administered together, gave greater suppression than when given separately. These findings suggest that EPF may be a potential candidate for use in treatment of MS and may be of use in combined therapy with IFN-beta.

Surges of increased T cell reactivity to an encephalitogenic region of myelin proteolipid protein occur more often in patients with multiple sclerosis than in healthy subjects.

We have previously shown that patients with multiple sclerosis (MS) have increased T cell responses to the immunodominant region (residues 184-209) of myelin proteolipid protein (PLP). The present study investigated whether this reactivity fluctuates over time and correlates with disease activity. We performed monthly limiting dilution assays for 12-16 mo in four healthy subjects and five patients with relapsing-remitting MS to quantify the frequencies of circulating T cells proliferating in response to PLP(41-58), PLP(184-199), PLP(190-209), myelin basic protein (MBP), MBP(82-100), and tetanus toxoid. Disease activity was monitored by clinical assessment and gadolinium-enhanced magnetic resonance imaging of the brain. There were fluctuations in the frequencies of autoreactive T cells in all subjects. Compared with healthy controls, MS patients had significantly more frequent surges of T cells reactive to the 184-209 region of PLP, but infrequent surges of T cell reactivity to MBP(82-100). There was temporal clustering of the surges of T cell reactivity to MBP(82-100) and MBP, suggesting T cell activation by environmental stimuli. Some clinical relapses were preceded by surges of T cell reactivity to PLP(184-209), and in one patient there was significant correlation between the frequency of T cells reactive to PLP(184-199) and the total number of gadolinium-enhancing magnetic resonance imaging lesions. However, other relapses were not associated with surges of T cell reactivity to the Ags tested. T cells reactive to PLP(184-209) may contribute to the development of some of the CNS lesions in MS.

A neuropathological analysis of experimental autoimmune encephalomyelitis with predominant brain stem and cerebellar involvement and differences between active and passive induction.

Experimental autoimmune encephalomyelitis (EAE) is an autoimmune demyelinating disease that can be induced in a variety of animal species and which is commonly used as an animal model of multiple sclerosis. In rodent EAE models, the clinical disease is typified by ascending paralysis; however, other clinical patterns can also be observed by inducing disease with particular peptides of myelin proteolipid protein (PLP) or myelin oligodendrocyte glycoprotein. Here we describe EAE induced in C3H/HeJ mice by inoculation with residues 190-209 of PLP. This form of EAE is manifested clinically by a movement disorder, with axial rotation of the head and trunk. Histologically, this form of EAE is characterized by predominant cerebellar or brain stem involvement, depending on whether EAE is induced by active immunization with the PLP peptide, or by passive transfer of T cells specific for the peptide. The inflammatory cell infiltrate is composed of polymorphonuclear cells and mononuclear cells. This rotatory form of EAE may be a useful model for studying the neuropathological characteristics of multiple sclerosis affecting the brain stem and cerebellum.

Maintenance of functional equivalence during paralogous Hox gene evolution.

Biological diversity is driven mainly by gene duplication followed by mutation and selection. This divergence in either regulatory or protein-coding sequences can result in quite different biological functions for even closely related genes. This concept is exemplified by the mammalian Hox gene complex, a group of 39 genes which are located on 4 linkage groups, dispersed on 4 chromosomes. The evolution of this complex began with amplification in cis of a primordial Hox gene to produce 13 members, followed by duplications in trans of much of the entire unit. As a consequence, Hox genes that occupy the same relative position along the 5' to 3' chromosomal coordinate (trans-paralogous genes) share more similarity in sequence and expression pattern than do adjacent Hox genes on the same chromosome. Studies in mice indicate that although individual family members may have unique biological roles, they also share overlapping functions with their paralogues. Here we show that the proteins encoded by the paralogous genes, Hoxa3 and Hoxd3, can carry out identical biological functions, and that the different roles attributed to these genes are the result of quantitative modulations in gene expression.

Clinical laboratory evaluation of a PCR assay for the detection of HCMV.

OBJECTIVE: In limited laboratory space and consonant with limited opportunities for contamination, to implement and incorporate into our diagnostic virology laboratory, a polymerase chain reaction assay for human cytomegalovirus detection with maximum sensitivity. DESIGN: Polymerase chain reaction, adapted for use with the enzyme uracil-n-glycosylase to avoid the potential for false positive reactions due to amplicon carryover was developed, optimized using two primer pairs, and performed on 361 specimens, i.e., body fluids and tissues submitted to the viral laboratory for detection of human cytomegalovirus. Polymerase chain reaction results were compared to shell vial assay. SETTING: Louisiana State University Health Sciences Center, Shreveport LA. MAIN OUTCOME MEASUREMENTS: Using the shell vial assay as the reference, analytical sensitivity (lower limit of detection) as well as laboratory sensitivity and specificity of both primer pairs. RESULTS: The lower limit of detection of our polymerase chain reaction assay was determined to be one focus-forming unit. Using the shell vial assay as the reference test, the sensitivity and specificity of both primer pairs were 96.5% and 94.3%, respectively. Polymerase chain reaction detected human cytomegalovirus in 6% of our culture-negative specimens. CONCLUSION: Based upon this study, our recommendations include the following: 1) a housekeeping gene amplification control is required for diagnostic polymerase chain reaction; 2) a single primer pair can be utilized for clinical work without sacrificing too much sensitivity; and 3) the laboratory should maintain close contact with clinicians to discuss polymerase chain reaction interpretation.

Targeting genes for self-excision in the germ line.

A procedure is described that directs the self-induced deletion of DNA sequences as they pass through the male germ line of mice. The testes-specific promoter from the angiotensin-converting enzyme gene was used to drive expression of the Cre-recombinase gene. Cre was linked to the selectable marker Neor, and the two genes flanked with loxP elements. This cassette was targeted to the Hoxa3 gene in mouse ES cells that were in turn used to generate chimeric mice. In these chimeras, somatic cells derived from the ES cells retained the cassette, but self-excision occurred in all ES-cell-derived sperm.

Increased circulating antiganglioside antibodies in primary and secondary progressive multiple sclerosis.

Plasma samples from 70 patients with multiple sclerosis (MS), 41 patients with other neurological diseases (OND), and 38 healthy subjects were examined for antibodies against gangliosides GM1, GM3, GD1a, GD1b, and GD3 using enzyme-linked immunosorbent assays. The percentages of subjects with increased anti-GM3 responses were significantly higher in the primary progressive MS (56.3%) and secondary progressive MS (42.9%) groups than in the relapsing-remitting MS (2.9%), healthy subject (2.6%), and OND (14.6%) groups. Elevated antiganglioside antibodies may be secondary to axonal damage or may be a cause of axonal damage and accumulating disability in progressive MS. In either case, they may serve as a marker of axonal damage in MS.

Autopathogenic T helper cell type 1 (Th1) and protective Th2 clones differ in their recognition of the autoantigenic peptide of myelin proteolipid protein.

We previously generated a panel of T helper cell 1 (Th1) clones specific for an encephalitogenic peptide of myelin proteolipid protein (PLP) peptide 139-151 (HSLGKWLGHPDKF) that induces experimental autoimmune encephalomyelitis (EAE) upon adoptive transfer. In spite of the differences in their T cell receptor (TCR) gene usage, all these Th1 clones required W144 as the primary and most critical TCR contact residue for the activation. In this study, we determined the TCR contact residues of a panel of Th2/Th0 clones specific for the PLP peptide 139-151 generated either by immunization with the PLP 139-151 peptide with anti- B7-1 antibody or by immunization with an altered peptide Q144. Using alanine-substituted peptide analogues of the native PLP peptide, we show that the Th2 clones have shifted their primary contact residue to the NH2-terminal end of the peptide. These Th2 cells do not show any dependence on the W144, but show a critical requirement for L141/G142 as their major TCR contact residue. Thus, in contrast with the Th1 clones that did not proliferate to A144-substituted peptide, the Th2 clones tolerated a substitution at position 144 and proliferated to A144 peptide. This alternative A144 reactive repertoire appears to have a critical role in the regulation of autoimmune response to PLP 139-151 because preimmunization with A144 to expand the L141/G142-reactive repertoire protects mice from developing EAE induced with the native PLP 139-151 peptide. These data suggest that a balance between two different T cell repertoires specific for same autoantigenic epitope can determine disease phenotype, i.e., resistance or susceptibility to an autoimmune disease.