Pediatric autoimmune neuropsychiatric disorder associated with group a streptococcal infection: the role of surgical treatment

Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcus (PANDAS) is a well-defined syndrome in which tics (motor and/or vocal) and/or obsessive compulsive disorders (OCD) consistently exacerbate in temporal correlation to a Group A beta-haemolytic streptococcal infection. In children with PANDAS, there is speculation about whether tonsillectomy or adenotonsillectomy might improve the neuropsychiatric course. Our objective was to examine whether such surgery impacted remission or, in patients without remission, modified clinical course of the disease, streptococcal antibody titers, neuronal antibodies or clinical severity of Obsessive-Compulsive Disorder (OCD) and/or tics. Study participants (n = 120) with positive PANDAS criteria were recruited, examined, and divided into surgical or non-surgery groups. The surgical group consisted of children with tonsillectomy or adenotonsillectomy (n=56). The remaining children were categorized as non-surgery (n=64). Clinical follow-up was made every 2 months for more than 2 years. Surgery did not affect symptomatology progression, streptococcal and neuronal antibodies, or the clinical severity of neuropsychiatric symptoms in these children. In conclusion, in our series clinical progression, antibody production, and neuropsychiatric symptom severity did not differ on the basis of surgical status. We cannot uphold surgical management as likely to impact positive remission rates, course of OCD/tics, or antibody concentrations in children with PANDAS.

Possible protective role of the 489C>T P2X7R polymorphism in Alzheimer's disease

Inflammation is a key factor in the onset and progression of Alzheimer's disease (AD). The P2X7 receptor (P2X7R) is increasingly recognized as key pro-inflammatory receptor. A recent study has shown that activation of microglia by amyloid β (Aβ) and associated release of IL-1β, requires P2X7R expression. In this study we assessed by RT-PCR in genomic DNA samples, the frequency of two single-nucleotide polymorphisms (SNP) of P2X7R in AD patients compared to age-matched non demented elderly. Our data show that the 489C>T SNP was significantly less frequent in AD patients than in controls (p=0.01), whereas there was no statistical difference in 1513A>C frequency in either groups. In addition, presence of the 1513C allele and absence of the 489C allele decreased the probability of having AD by about four fold. In conclusion, our data show a strong negative association between the P2X7R 489C>T polymorphism and AD, especially in the presence of the 1513C allele.

Implication of HLA-C and KIR alleles in human papillomavirus infection and associated cervical lesions

Human papillomavirus (HPV) regulation of host immune response leads to cervical lesions. In particular, natural killer (NK) cells are crucial for HPV control. Since specific HLA-I/KIR interactions modify NK cell activation, we analyzed HLA-C and KIR alleles in HPV infection and lesion development in 150 controls, 33 condyloma acuminatum, and 111 invasive cervical cancer (ICC) patients. We showed an increase in HLA-C1/KIR2DL2 and HLA-C1/KIR2DL3 pairs in HPV high-risk infected patients (OR 3.05, 3.24) with ICC (OR 1.33, 3.68). These data suggest HLA-C and KIR typing as risk marker for HPV infection and lesion evolution.

Impact of HLA-G analysis in prevention, diagnosis and treatment of pathological conditions

Human leukocyte antigen-G (HLA-G) is a non-classical HLA class I molecule that differs from classical HLA class I molecules by low polymorphism and tissue distribution. HLA-G is a tolerogenic molecule with an immune-modulatory and anti-inflammatory function on both innate and adaptative immunity. This peculiar characteristic of HLA-G has led to investigations of its role in pathological conditions in order to define possible uses in diagnosis, prevention and treatment. In recent years, HLA-G has been shown to have an important implication in different inflammatory and autoimmune diseases, pregnancy complications, tumor development and aggressiveness, and susceptibility to viral infections. In fact, HLA-G molecules have been reported to alternate at both genetic and protein level in different disease situations, supporting its crucial role in pathological conditions. Specific pathologies show altered levels of soluble (s)HLA-G and different HLA-G gene polymorphisms seem to correlate with disease. This review aims to update scientific knowledge on the contribution of HLA-G in managing pathological conditions.

HLA-G is a component of the chronic lymphocytic leukemia escape repertoire to generate immune suppression: impact of the HLA-G 14 base pair (rs66554220) polymorphism

This work investigates the possibility that HLA-G, a molecule modulating innate and adaptive immunity, is part of an immune escape strategy of chronic lymphocytic leukemia cells. A 14 base pair insertion/deletion polymorphism (rs66554220) in the 3'-untranslated region of HLA-G influences mRNA stability and protein expression. The analysis of a cohort of patients with chronic lymphocytic leukemia confirmed that del/del individuals are characterized by higher levels of surface and soluble HLA-G than subjects with the other two genotypes. In line with its role in immunomodulation, the percentage of regulatory T lymphocytes is higher in del/del patients than in patients with the other genotypes and correlates with the amounts of surface or soluble HLA-G. Furthermore, addition of sHLA-G-rich plasma from patients with chronic lymphocytic leukemia induces natural killer cell apoptosis and impairs natural killer cell lysis, with effects proportional to the amount of soluble HLA-G added. Lastly, the presence of an HLA-G 14 base pair polymorphism is of prognostic value, with del/del patients showing reduced overall survival, as compared to those with other genotypes. These results suggest that: (i) the HLA-G 14 base pair polymorphism influences the levels of surface and soluble HLA-G expression, and (ii) the over-expression of HLA-G molecules contributes to creating tolerogenic conditions.

High prevalence of HHV8 infection and specific killer cell immunoglobulin-like receptors allotypes in Sardinian patients with type 2 diabetes mellitus

The development of type 2 diabetes is thought to involve both environmental, possibly infectious, and genetic factors. Recently, a high prevalence of human herpesvirus 8 (HHV8) infection was observed in type 2 diabetes patients, and specific killer cell immunoglobulin-like receptors (KIR) allotypes were associated to both increased susceptibility to herpesvirus infection and risk to develop diabetes. However, no clear gene-disease or virus-disease associations have been established. To investigate the possible interplay between HHV8 infection, KIR allotype and type 2 diabetes, virus prevalence and KIR genotype were analyzed by PCR in 168 patients affected by type 2 diabetes and 108 control individuals belonging to the Sardinian population. Results showed a significant increase of HHV8 prevalence in type 2 diabetes patients versus controls (57% vs. 17%, P < 0.001), and a significant increase of KIR2DL2/DS2 homozygosity in diabetes patients infected with HHV8 compared to uninfected ones (64% vs. 14%, P < 0.0001), resulting in a significant OR of 11.31. In addition, the analysis of the frequency of the KIR2DL2/DS2 receptor and its HLA-C1 ligand, accordingly to the status of HHV8 infection, showed a significant increased correlation between KIR2DL2/DS2, type 2 diabetes and HLA-C1C1 genotype in the type 2 diabetes patients infected with HHV8 compared to uninfected ones (62% vs. 15%, P < 0.0001, OR = 8.64). These findings provide preliminary evidence that HHV8 infection might be a cofactor for type 2 diabetes in a specific subset of genetically susceptible individuals, and suggest the possibility that such patients might have an impaired immune-mediated component contributing to the development of type 2 diabetes.

Intrathecal soluble HLA-E correlates with disease activity in patients with multiple sclerosis and may cooperate with soluble HLA-G in the resolution of neuroinflammation

Expression and function of the immunoregulatory molecule HLA-E was investigated in patients with relapsing-remitting (RR) multiple sclerosis (MS). Serum and cerebrospinal fluid (CSF) soluble (s)HLA-E and -G levels were measured by ELISA in 80 RRMS patients. Controls were patients with other inflammatory neurological disorders (OIND, n = 81) and noninflammatory neurological disorders (NIND, n = 86). Serum sHLA-E concentrations were higher in RRMS than in NIND patients only. CSF sHLA-E concentrations were higher in RRMS than controls. Increased CSF sHLA-E levels were detected in MRI inactive and clinically stable RRMS patients. sHLA-E intrathecal synthesis (ITS) was higher in RRMS than controls, and the number of patients with sHLA-E ITS above cut-off was higher i) in MS than controls, and ii) in clinically stable than clinically active MS patients. sHLA-E CSF levels and ITS correlated with i) the same sHLA-G parameters, and ii) disease duration. HLA-E expression and co-expression with CD markers were investigated in MS plaques from three different cases by immunohistochemistry and confocal microscopy, respectively. Infiltrating T lymphocytes and macrophages, as well as resident microglial cells and astrocytes expressed HLA-E. CSF samples from MS patients were finally tested for inhibitory activity of in vitro CTL and NK cell mediated cytotoxicity. sHLA-E⁺ were more effective than sHLA-E⁻ CSF samples in such inhibition. Maximum inhibition was achieved with sHLA-E⁺/sHLA-G⁺ CSF samples In conclusion, increased sHLA-E CSF levels may play an immunomodulatory role in MS, contributing to the inhibition of intrathecal inflammatory response. The potential of sHLA-E as biomarker of MS activity warrants further investigation.

Matrix metalloproteinase-2 (MMP-2) generates soluble HLA-G1 by cell surface proteolytic shedding

Human leukocyte antigen-G (HLA-G) molecules are non-classical HLA class I antigens with an important role in pregnancy immune regulation and inflammation control. Soluble HLA-G proteins can be generated through two mechanisms: alternative splicing and proteolytic release, which is known to be metalloprotease mediated. Among this class of enzymes, matrix metalloproteinases (MMPs) might be involved in the HLA-G1 membrane cleavage. Of particular interest are MMP-2 and MMP-9, which regulate the inflammatory process by cytokine and chemokine modulation. We evaluated the effect of MMP-9 and MMP-2 on HLA-G1 membrane shedding. In particular, we analyzed the in vitro effect of these two gelatinases on the secretion of HLA-G1 via proteolytic cleavage in 221-G1-transfected cell line, in JEG3 cell line, and in peripheral blood mononuclear cells. The results obtained by both cell lines showed the role of MMP-2 in HLA-G1 shedding. On the contrary, MMP-9 was not involved in this process. In addition, we identified three possible highly specific cleavage sites for MMP-2, whereas none were detected for MMP-9. This study suggests an effective link between MMP-2 and HLA-G1 shedding, increasing our knowledge on the regulatory machinery beyond HLA-G regulation in physiological and pathological conditions.

Programmable interactions of functionalized single bioparticles in a dielectrophoresis-based microarray chip

Manipulating single biological objects is a major unmet challenge of biomedicine. Herein, we describe a lab-on-a-chip platform based on dielectrophoresis (DEP). The DEParray is a prototypal version consisting of 320 × 320 arrayed electrodes generating >10,000 spherical DEP cages. It allows the capture and software-guided movement to predetermined spatial coordinates of single biological objects. With the DEParray we demonstrate (a) forced interaction between a single, preselected target cell and a programmable number of either microspheres or natural killer (NK) cells, (b) on-chip immunophenotypic discrimination of individual cells based on differential rosetting with microspheres functionalized with monoclonal antibodies to an inhibitory NK cell ligand (HLA-G), (c) on-chip, real-time (few minutes) assessment of immune lysis by either visual inspection or semiautomated, time-lapse reading of a fluorescent dye released from NK cell-sensitive targets, and (d) manipulation and immunophenotyping with limiting amounts (about 500) cells. To our knowledge, this is the first report describing a DEP-based lab-on-a-chip platform for the quick, arrayed, software-guided binding of individually moved biological objects, the targeting of single cells with microspheres, and the real-time characterization of immunophenotypes. The DEParray candidates as a discovery tool for novel cell:cell interactions with no prior (immuno)phenotypic knowledge.

Primary headaches in children: clinical findings on the association with other conditions

The aim of the present study is to report on the frequency of some comorbidities in primary headaches in childhood. Two hundred and eighty children (175 males and 105 females; ratio 1.7:1), aged 4 to 14 years, affected by primary headaches were consecutively enrolled in this study. In direct interviews, parents and children gave information about the association of their headaches with different conditions including asthma and allergic disorders, convulsive episodes, sleep disorders and increased body weight, affections some time associated in the literature to headache as comorbidities . In addition, anxiety and depression, attention deficit/hyperactivity disorder, tics, learning disabilities and obsessive-compulsive disorders, using psycho-diagnostic scales were evaluated. Two hundred and eighty children matched for age, sex, race and socio-economic status, were used as controls. No significant association of primary headaches was found with asthma and allergic disorders, convulsive episodes, sleep disorders and increased body weight. Overall behavioral disorders were more common in children who experienced headache than in controls. A significant association of primary headache was found with anxiety and depression (p value &#60; 0.001), but not with the other psychiatric disorders. Primary headaches in children are not associated with most of the psychiatric and systemic conditions herein investigated. On the contrary, there was a significant association with anxiety and depression, as frequently reported in adults.

HLA-G may predict the disease course in patients with early rheumatoid arthritis

The current management of early rheumatoid arthritis (ERA) is to start an intensive treatment as soon as possible. To avoid under/overtreatment, it is important to identify reliable ERA evolution biomarkers. HLA-G molecules has been associated with rheumatoid arthritis, suggesting a role in disease regulation. HLA-G antigens are expressed as membrane bound and soluble isoforms (mHLA-G, sHLA-G) that act as ligand for immune-inhibitory receptors (ILT2, ILT4, KIR2DL4). Expression of HLA-G is influenced by a 14 bp insertion/deletion polymorphism in exon 8 of the gene, where the deletion is associated with mRNA stability. We analyzed 23 ERA patients during a 12 months follow-up disease treatment for sHLA-G, IL-1beta, IL-6, IL-10 and TNF-alpha levels in plasma samples by ELISA, mHLA-G and ILT2 expression on peripheral blood CD14 positive cells by flow cytometry and typed HLA-G 14 bp deletion/insertion polymorphism by Real-Time PCR. Disease status (DAS28), ultrasonography with power Doppler and laboratory data were checked. Cytokine levels confirmed the anti-inflammatory effect of the treatment. sHLA-G, mHLA-G and ILT2 expression inversely correlated with DAS28 disease scores. The frequency of 14 bp deletion allele increased in patients with disease remission. Based on these results, HLA-G may be a candidate biomarker to evaluate early prognosis and disease activity in ERA patients.

Soluble human leukocyte antigen-g and its insertion/deletion polymorphism in papillary thyroid carcinoma: novel potential biomarkers of disease?

INTRODUCTION

Human leukocyte antigen-G (HLA-G), a nonclassical major histocompatibility complex class I antigen, plays a pivotal role in immune tolerance and a paradoxical role in cancers.

AIMS

Our aims were to evaluate plasma soluble HLA-G (sHLA-G) concentrations and the 14-bp insertion/deletion polymorphism of the HLA-G gene in patients with papillary thyroid carcinoma (PTC) or Hashimoto's thyroiditis (HT) and to assess the possible association of these parameters with PTC aggressiveness.

METHODS

Samples for the analysis of sHLA-G and +14/-14-bp HLA-G polymorphism were obtained from 121 patients with HT and 183 with PTC; 245 gender- and age-matched healthy subjects served as controls. PTC histopathological aggressiveness was defined according to the last American Thyroid Association guidelines.

RESULTS

Positive serum antithyroid antibody titers were observed in 22% of PTC patients and lymphocyte infiltration of thyroid parenchyma at histological examination in 21%, whereas both circulating and histological autoimmunity was detectable in 12% of PTC patients. No differences in the +14/-14-bp polymorphism frequencies were observed between the study groups. The prevalence of detectable sHLA-G was lower in healthy controls (52%) as compared with both HT (57%) and PTC (62%) patients. By stratifying the study groups according to sHLA-G level of positive subjects, significantly higher plasma sHLA-G values in PTC (42.9 ± 3.3 ng/ml; P = 0.002) and HT patients (49.1 ± 2.6 ng/ml; P < 0.002) as compared with healthy controls (8.5 ± 1.8 ng/ml) were obtained. Moreover, PTC patients with detectable plasma sHLA-G levels showed a higher aggressive behavior (P < 0.04) than those without.

CONCLUSIONS

Although confirming the frequent association between PTC and chronic autoimmune thyroiditis, these data suggest that elevated circulating sHLA-G levels, besides an important signal of alterations of immune homeostasis, may be considered a potential, novel marker of PTC histopathological aggressiveness at diagnosis. Additional studies are needed to confirm the actual role and clinical relevance of the HLA-G complex in PTC development and progression.

Virologic and immunologic evidence supporting an association between HHV-6 and Hashimoto's thyroiditis

Hashimoto's thyroiditis (HT) is the most common of all thyroid diseases and is characterized by abundant lymphocyte infiltrate and thyroid impairment, caused by various cell- and antibody-mediated immune processes. Viral infections have been suggested as possible environmental triggers, but conclusive data are not available. We analyzed the presence and transcriptional state of human herpesvirus 6 (HHV-6) in thyroid fine needle aspirates (FNA) and peripheral blood mononuclear cells (PBMCs) from 34 HT patients and 28 controls, showing that HHV-6 DNA prevalence (82% vs. 10%, p≤0.001) and viral load were significantly increased in FNA from HT patients, and thyrocytes from HT FNA displayed a 100-fold higher HHV-6 DNA load compared to infiltrating lymphocytes. In addition, while HHV-6 was strictly latent in positive samples from controls, a low grade acute infection was detected in HT samples. HHV-6 variant characterization was carried out in 10 HT FNA samples, determining that all specimens harbored HHV-6 Variant A.

The tropism of HHV-6 for thyroid cells was verified by infection of Nthy-ori3-1, a thyroid follicular epithelial cell line, showing that thyrocytes are permissive to HHV-6 replication, which induces de novo expression of HLA class II antigens. Furthermore, HHV-6-infected Nthy-ori3-1 cells become targets for NK-mediated killing, NK cells from HT patients show a significantly more efficient killing of HHV-6 infected thyroid cells than healthy controls, and HT patients have increased T-cell responses to HHV-6 U94 protein, associated to viral latency. These observations suggest a potential role for HHV-6 (possibly variant A) in the development or triggering of HT.

Hashimoto's thyroiditis (HT) is a very common autoimmune disease of the thyroid. In addition to genetic background, several viruses, including herpesviruses, have been suggested to play a role as possible environmental triggers of disease, but conclusive data are still lacking. The anecdotal presence of human herpesvirus 6 (HHV-6) in HT specimens prompted us to study a possible association between HHV-6 and HT. Our analysis of fine needle thyroid aspirates and blood from HT patients and controls shows that HHV-6 prevalence and load are highly increased in HT patients. Furthermore, HT-derived thyrocytes harbor active virus, whereas HHV-6 is strictly latent in the few virus-positive controls. We also report that HHV-6 infects thyroid cells, inducing de novo expression of HLA-II surface antigens. Consequently, thyrocytes might behave as antigen presenting cells. Interestingly, immune cells from HT patients kill HHV-6-infected thyrocytes more efficiently than controls. Also, HT patients, but not controls, have specific T-cell responses to HHV-6 U94 protein. It is difficult to prove etiologic links between viral infections and diseases, especially in the case of a ubiquitous agent such as HHV -6. Nevertheless, our findings indicate that HHV-6 might contribute to HT development, and argue for a pathogenic association between HHV-6 and HT.

Role of HLA-G 14bp deletion/insertion and +3142C>G polymorphisms in the production of sHLA-G molecules in relapsing-remitting multiple sclerosis

HLA-G is believed to act as an anti-inflammatory molecule in Multiple Sclerosis (MS). The 3' untranslated region of the HLA-G gene is characterized by two polymorphisms, DEL/INS14bp and +3142C>G, which control soluble HLA-G (sHLA-G) production. The influence of these two HLA-G variants on sHLA-G serum and cerebrospinal fluid (CSF) levels was investigated in 69 Relapsing-Remitting MS patients grouped in magnetic resonance imaging (MRI) inactive and active disease. Serum and CSF sHLA-G levels were more elevated in high than in low DEL/INS 14bp and +3142C>G sHLA-G producers and were different among the various combined HLA-G genotypes in both MRI inactive and active diseases. The highest and the lowest sHLA-G values were identified in MS patients with C/C,DEL/DEL and G/G,INS/INS genotypes, respectively. Our preliminary findings suggest that serum and CSF sHLA-G levels in MS could be influenced by HLA-G polymorphisms irrespective of the inflammatory microenvironment.

An accurate and reliable real time SNP genotyping assay for the HLA-G +3142 bp C>G polymorphism

Human leukocyte antigen (HLA)-G is a non classical HLA class I antigen with immuno-modulatory functions. The HLA-G gene is characterized by a +3142C>G variant in the 3' untranslated region which is suggested to control protein production and to be associated with pathological conditions. DNAs form 221 randomly selected healthy subjects were genotyped for HLA-G +3142C>G polymorphism by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) (BaeGI), real-time PCR and sequencing. The 19% of the PCR-RFLP heterozygous samples were genotyped as 3142GG by real-time PCR and sequencing. This disagreement is caused by digestion efficiency in PCR-RFLP. This real-time PCR method will guarantee an accurate genotyping for future research and clinical purposes, where large cohorts should be tested.