Evaluation of a rapid Loop Mediated Isothermal Amplification (LAMP) test for the laboratory diagnosis of sexually transmitted infections

Sexually transmitted infections (STIs) have seen a considerable increase in the last years and given the health burden they may represent from both a personal and community perspective, they require surveillance and prevention programmes based on a timely and decentralized diagnosis. In this context, user-friendly rapid molecular tests may represent a good trade-off between diagnostic accuracy, accessibility and affordability. In this study we evaluated the diagnostic performance of a new real-time LAMP (Loop Mediated Isothermal Amplification) method for the rapid detection and differentiation of 7 major sexually transmissible pathogens by analysing real clinical samples (genital and extra-genital matrices) from individuals with suspected STIs. The assay showed good overall diagnostic performances in terms of sensitivity, specificity and concordance with a gold-standard PCR-based molecular method. This assay, not requiring specialised laboratory technicians or expensive instrumentation, but nonetheless capable of guaranteeing accurate results, is within the reach of outpatient settings, obstetrics, and gynaecology clinic, hence ensuring on-field access to early diagnosis.

No(cebo) Vax: COVID-19 Vaccine Beliefs Are Important Determinants of Both Occurrence and Perceived Severity of Common Vaccines' Adverse Effects

This study highlights the role of psychological influences in triggering and amplifying the adverse effects of the COVID-19 vaccine (i.e., nocebo effects). Fear, beliefs, and expectations about the COVID-19 vaccine, trust in health and scientific institutions, and stable personality traits were measured in 315 adult Italian citizens (145 men) during the 15-min waiting time after vaccination. The occurrence and severity of 10 potential adverse effects were assessed 24 hr later. Nonpharmacological variables predicted nearly 30% of the severity of the vaccine's adverse effects. Expectations are important determinants of adverse effects from vaccines, and the results of the path analyses show that these expectations stem primarily from people's vaccine beliefs and attitudes, which can be changed. Implications for increasing vaccine acceptability and limiting the nocebo effect are discussed.

Omicron Sub-Lineage BA.5 and Recombinant XBB Evasion from Antibody Neutralisation in BNT162b2 Vaccine Recipients

The recent emergence of a number of new SARS-CoV-2 variants resulting from recombination between two distinct parental lineages or sub-lineages within the same lineage has sparked the debate regarding potential enhanced viral infectivity and immune escape. Among these, XBB, recombinant of BA.2.10 and BA.2.75, has caused major concern in some countries due to its rapid increase in prevalence. In this study, we tested XBB escape capacity from mRNA-vaccine-induced (BNT162b2) neutralising antibodies compared to B.1 ancestral lineage and another co-circulating variant (B.1.1.529 BA.5) by analysing sera collected 30 days after the second dose in 92 healthcare workers. Our data highlighted an enhanced and statistically significant immune escape ability of the XBB recombinant. Although these are preliminary results, this study highlights the importance of immune escape monitoring of new and forthcoming variants and of the reformulation of existing vaccines.

Kinetics of dried blood spot-measured anti-SARS-CoV2 Spike IgG in mRNA-vaccinated healthcare workers

Introduction

One of the major criticisms facing the research community during SARS-CoV2 pandemic was the lack of large-scale, longitudinal data on the efficacy of the SARS-CoV2 mRNA vaccines. Currently, even if COVID-19 antiviral treatments have been authorized by European Medicine Agency, prevention through approved specific vaccines is the best approach available in order to contain the ongoing pandemic.

Objectives

Here, we studied the antibody kinetic over a one-year period from vaccination with the Pfizer-BioNTech (Pfizer) vaccines and subsequent boosting with either the BioNTech or Moderna (Spikevax) vaccines in a large cohort of 8,071 healthcare workers (HCW). We also described the impact of SARS-CoV2 infection on antibody kinetic over the same period.

Methods

We assessed the anti SARS-CoV2 Spike IgG antibody kinetic by the high throughput dried blood spot (DBS) collection method and the GSP®/DELFIA® Anti-SARS-CoV2 IgG assay (PerkinElmer®).

Results

Our data support existing models showing that SARS-CoV2 vaccination elicits strong initial antibodies responses that decline with time but are transitorily increased by administering a vaccine booster. We also showed that using heterologous vaccine/booster combinations a stronger antibody response was elicited than utilizing a booster from the same vaccine manufacturer. Furthermore, by considering the impact of SARS-CoV2 infection occurrence in proximity to the scheduled booster administration, we confirmed that booster dose did not contribute significantly to elicit higher antibody responses.

Conclusion

DBS sampling in our large population of HCWs was fundamental to collect a large number of specimens and to clarify the effective mRNA vaccine-induced antibody kinetic and the role of both heterologous boosters and SARS-CoV2 infection in modulating antibody responses.

Efficacy of SARS-CoV-2 Vaccination in Dialysis Patients: Epidemiological Analysis and Evaluation of the Clinical Progress

This study investigated the impact of the fourth COVID-19 pandemic wave on dialysis patients of Romagna territory, assessing the associations of vaccination status with infection risk, clinical severity and mortality. From November 2021 to February 2022, an epidemiological search was conducted on 829 patients under dialysis treatment for at least one month. The data were then analyzed with reference to the general population of the same area. A temporal comparison was also carried out with the previous pandemic waves (from March 2020 to October 2021). The epidemiological evolution over time in the dialysis population and in Romagna citizens replicated the global trend, as the peak of the fourth wave corresponded to the time of maximum diffusion of omicron variant (B.1.1.529). Of 771 prevalent dialysis patients at the beginning of the study, 109 (14.1%) contracted SARS-CoV-2 infection during the 4-month observation period. Vaccine adherence in the dialysis population of the reference area was above 95%. Compared to fully or partially vaccinated subjects, the unvaccinated ones showed a significantly higher proportion of infections (12.5% vs. 27.0% p = 0.0341), a more frequent need for hospitalization (22.2% vs. 50.0%) and a 3.3-fold increased mortality risk. These findings confirm the effectiveness of COVID-19 vaccines in keeping infectious risk under control and ameliorating clinical outcomes in immunocompromised patients.

Mutational induction in SARS-CoV-2 major lineages by experimental exposure to neutralising sera

The ongoing evolution of SARS-CoV-2 and the emergence of new viral variants bearing specific escape mutations responsible for immune evasion from antibody neutralisation has required a more accurate characterisation of the immune response as one of the evolutive forces behind viral adaptation to a largely immunised human population. In this work, culturing in the presence of neutralising sera vigorously promoted mutagenesis leading to the acquisition of known escape mutations on the spike as well as new presumptive escape mutations on structural proteins whose role as target of the neutralizing antibody response might have been thus far widely neglected. From this perspective, this study, in addition to tracing the past evolution of the species back to interactions with neutralising antibody immune response, also offers a glimpse into future evolutive scenarios.

126. Magnitude and Dynamics of the T-Cell Response to SARS-CoV-2 Infection and Vaccination

Background

T cells are central to the early identification and clearance of viral infections and support antibody generation by B cells, making them desirable for assessing the immune response to SARS-CoV-2 infection and vaccines. We combined 2 high-throughput immune profiling methods to create a quantitative picture of the SARS-CoV-2 T-cell response that is highly sensitive, durable, diagnostic, and discriminatory between natural infection and vaccination.

Methods

We deeply characterized 116 convalescent COVID-19 subjects by experimentally mapping CD8 and CD4 T-cell responses via antigen stimulation to 545 Human Leukocyte Antigen (HLA) class I and 284 class II viral peptides. We also performed T-cell receptor (TCR) repertoire sequencing on 1815 samples from 1521 PCR-confirmed SARS-CoV-2 cases and 3500 controls to identify shared public TCRs from SARS-CoV-2-associated CD8 and CD4 T cells. Combining these approaches with additional samples from vaccinated individuals, we characterized the response to natural infection as well as vaccination by separating responses to spike protein from other viral targets.

Results

We find that T-cell responses are often driven by a few immunodominant, HLA-restricted epitopes. As expected, the SARS-CoV-2 T-cell response peaks about 1-2 weeks after infection and is detectable at least several months after recovery. Applying these data, we trained a classifier to diagnose past SARS-CoV-2 infection based solely on TCR sequencing from blood samples and observed, at 99.8% specificity, high sensitivity soon after diagnosis (Day 3–7 = 85.1%; Day 8–14 = 94.8%) that persists after recovery (Day 29+/convalescent = 95.4%). Finally, by evaluating TCRs binding epitopes targeting all non-spike SARS-CoV-2 proteins, we were able to separate natural infection from vaccination with > 99% specificity.

Conclusion

TCR repertoire sequencing from whole blood reliably measures the adaptive immune response to SARS-CoV-2 soon after viral antigenic exposure (before antibodies are typically detectable) as well as at later time points, and distinguishes post-infection vs. vaccine immune responses with high specificity. This approach to characterizing the cellular immune response has applications in clinical diagnostics as well as vaccine development and monitoring.

Disclosures

Thomas M. Snyder, PhD, Adaptive Biotechnologies (Employee, Shareholder) Rachel M. Gittelman, PhD, Adaptive Biotechnologies (Employee, Shareholder) Mark Klinger, PhD, Adaptive Biotechnologies (Employee, Shareholder) Damon H. May, PhD, Adaptive Biotechnologies (Employee, Shareholder) Edward J. Osborne, PhD, Adaptive Biotechnologies (Employee, Shareholder) Ruth Taniguchi, PhD, Adaptive Biotechnologies (Employee, Shareholder) H. Jabran Zahid, PhD, Microsoft Research (Employee, Shareholder) Rebecca Elyanow, PhD, Adaptive Biotechnologies (Employee, Shareholder) Sudeb C. Dalai, MD, PhD, Adaptive Biotechnologies (Employee, Shareholder) Ian M. Kaplan, PhD, Adaptive Biotechnologies (Employee, Shareholder) Jennifer N. Dines, MD, Adaptive Biotechnologies (Employee, Shareholder) Matthew T. Noakes, PhD, Adaptive Biotechnologies (Employee, Shareholder) Ravi Pandya, PhD, Microsoft Research (Employee, Shareholder) Lance Baldo, MD, Adaptive Biotechnologies (Employee, Shareholder, Leadership Interest) James R. Heath, PhD, Merck (Research Grant or Support, Funding (from BARDA) for the ISB INCOV project, but had no role in planning the research or in writing the paper.) Joaquin Martinez-Lopez, MD, PhD, Adaptive Biotechnologies (Consultant) Jonathan M. Carlson, PhD, Microsoft Research (Employee, Shareholder) Harlan S. Robins, PhD, Adaptive Biotechnologies (Board Member, Employee, Shareholder)

COVID-19 Infection: Viral Clearance and Antibody Response in Dialysis Patients and Renal Transplant Recipients

BACKGROUND/AIMS

The coronavirus disease 2019 (CO-VID-19) pandemic is the major current health emergency worldwide, adding a significant burden also to the community of nephrologists for the management of their patients. Here, we analyzed the impact of COVID-19 infection in renal patients to assess the time to viral clearance, together with the production and persistence of IgG and IgM antibody response, in consideration of the altered immune capacity of this fragile population.

METHODS

Viral clearance and antibody kinetics were investigated in 49 renal patients recovered from COVID-19 infection: 7 of them with chronic decompensated renal failure, 31 under dialysis treatment, and 11 kidney transplant recipients.

RESULTS

The time span between the diagnosis of infection and recovery based on laboratory testing (2 negative nasopharyngeal swabs in consecutive days) was 31.7 ± 13.3 days. Three new positive cases were detected from 8 to 13 days following recovery. At the first serological determination after swab negativization, all the patients developed IgG and IgM antibodies. The semiquantitative analysis showed a progressive increase in IgG and a slow reduction in IgM.

DISCUSSION/CONCLUSION

In subjects with decompensated chronic kidney disease, under dialysis and in transplant recipients, viral clearance is lengthened compared to the general population. However, in spite of their common status of immunodepression, all of them were able to produce specific antibodies. These data might provide useful insights for monitoring and planning health-care activities in the weak category of patients with compromised renal function recovered from COVID-19.

[Resilience in COVID-19 times: general considerations on the recovery of a 93-year-old patient on haemodialysis treatment]

We report the case of a 93-year-old woman on haemodialysis treatment for more than 30 months and with multiple comorbidities who recovered from a Covid-19 infection without any significant clinical problems. The patient has shown a delay in viral clearance with swab test negativization (confirmed) after 33 days; after testing positive again, she has resulted persistently negative, (confirmed after 49 days). After the first negative swab, IgG and IgM antibodies have been found; these have remained persistently positive after a month. As well as highlighting an unexpected resilience in an extremely fragile context, the analysis of this case draws attention to patients' management and, potentially, to the need to arrange dialysis treatments in isolation for some time after their "laboratory recovery".

Magnitude and Dynamics of the T-Cell Response to SARS-CoV-2 Infection at Both Individual and Population Levels

T cells are involved in the early identification and clearance of viral infections and also support the development of antibodies by B cells. This central role for T cells makes them a desirable target for assessing the immune response to SARS-CoV-2 infection. Here, we combined two high-throughput immune profiling methods to create a quantitative picture of the T-cell response to SARS-CoV-2. First, at the individual level, we deeply characterized 3 acutely infected and 58 recovered COVID-19 subjects by experimentally mapping their CD8 T-cell response through antigen stimulation to 545 Human Leukocyte Antigen (HLA) class I presented viral peptides (class II data in a forthcoming study). Then, at the population level, we performed T-cell repertoire sequencing on 1,815 samples (from 1,521 COVID-19 subjects) as well as 3,500 controls to identify shared "public" T-cell receptors (TCRs) associated with SARS-CoV-2 infection from both CD8 and CD4 T cells. Collectively, our data reveal that CD8 T-cell responses are often driven by a few immunodominant, HLA-restricted epitopes. As expected, the T-cell response to SARS-CoV-2 peaks about one to two weeks after infection and is detectable for at least several months after recovery. As an application of these data, we trained a classifier to diagnose SARS-CoV-2 infection based solely on TCR sequencing from blood samples, and observed, at 99.8% specificity, high early sensitivity soon after diagnosis (Day 3-7 = 85.1% [95% CI = 79.9-89.7]; Day 8-14 = 94.8% [90.7-98.4]) as well as lasting sensitivity after recovery (Day 29+/convalescent = 95.4% [92.1-98.3]). These results demonstrate an approach to reliably assess the adaptive immune response both soon after viral antigenic exposure (before antibodies are typically detectable) as well as at later time points. This blood-based molecular approach to characterizing the cellular immune response has applications in clinical diagnostics as well as in vaccine development and monitoring.

[Acro-ischemic injuries in children-adolescents during CoViD-19 pandemic: from lifestyle changes due to lockdown to interferone.]

At the end of March 2020, just over a month after the first ascertained case of CoViD-19 infection in Italy, the first reports of acute lesions of acro-ischemia appeared, especially in pre-adolescents and adolescents. These manifestations have been called in the course of these months in various ways, from "acro-ischemia acuta", "erythema pernio", "chilblains", up to characterize them more recently as "CoViD Toes". Clinical manifestations do not usually associate with other typical symptoms of Covid-19 and do not find a classical and defined serological antibody response (IgG and IgM). From a clinical point of view it is a localized and self-resolving problem of an interesting and relatively new pathogenetic model of disease in relation to a viral agent. Future studies must make us understand if there is in this specific condition a low viral load is not detectable by current methods and if this explains the inability to produce an adequate immune response for CoViD-19. It is important to determine whether the interferon immune response in some subjects can be the cause of both the low viremia and the endothelial damage so localized in the acral-site, as happens in other models of diseases (chilblain-lupus like). On the contrary, some authors believe that the acral lesions are attributable to chilblains caused by a series of favourable environmental conditions due to forced enclosure. We report the descriptive experience of 14 cases of acro-ischemia in children and adolescents observed in the territorial area of Ravenna and Rimini. The cases were subjected to the nasopharyngeal swab and to the search for antibodies with ELISA method for CoViD-19 both with negative results.

A large-scale database of T-cell receptor beta (TCRβ) sequences and binding associations from natural and synthetic exposure to SARS-CoV-2

We describe the establishment and current content of the ImmuneCODE™ database, which includes hundreds of millions of T-cell Receptor (TCR) sequences from over 1,400 subjects exposed to or infected with the SARS-CoV-2 virus, as well as over 135,000 high-confidence SARS-CoV-2-specific TCRs. This database is made freely available, and the data contained in it can be downloaded and analyzed online or offline to assist with the global efforts to understand the immune response to the SARS-CoV-2 virus and develop new interventions.

Multicenter Evaluation of the C6 Lyme ELISA Kit for the Diagnosis of Lyme Disease

Lyme disease (LD), caused by infection with Borrelia burgdorferi, is the most common tick-borne infection in many regions of Eurasia. Antibody detection is the most frequently used laboratory test, favoring a two-step serodiagnostic algorithm; immunoenzymatic detection of antibodies to C6 has been shown to perform similarly to a standard two-step workflow. The aim of this study was the performance evaluation of the C6 Lyme ELISA kit compared to a standard two-step algorithm in three laboratories located in the northeastern region of Italy which cater to areas with different LD epidemiology. A total of 804 samples were tested, of which 695 gave concordant results between C6 testing and routine workflow (564 negative, 131 positive). Wherever available, clinical presentation and additional laboratory tests were analyzed to solve discrepancies. The C6 based method showed a good concordance with the standard two-step algorithm (Cohen’s κ = 0.619), however, the distribution of discrepancies seems to point towards a slightly lower specificity of C6 testing, which is supported by literature and could impact on patient management. The C6 ELISA, therefore, is not an ideal stand-alone test; however, if integrated into a two-step algorithm, it might play a part in achieving a sensitive, specific laboratory diagnosis of LD.

HIV-1 early and late diagnosis in the Emilia Romagna Region (Italy): a three year study

It is crucial to establish the timing of infection and distinguish between early and long-lasting HIV-1 infections not only for partner notification and epidemiological surveillance, but also to offer early drug treatment and contain the spread of infection. This study analyzed serum and/or plasma samples with a first positive HIV antibody/antigen result coming from different Medical Centers in the Emilia Romagna Region, North East Italy, using the avidity assay, Western Blotting, RNA viral load, CD4 cell counts and genotyping assay. From May 2013 to May 2016, we certified 845 new HIV-1 infections, 18.7% of which were classified on the basis of avidity index as recent infections and 81.3% as long-lasting infections, with an estimated conversion time exceeding six months at the time of study. Western Blotting showed reactivity to only one or two HIV-1 proteins in recently infected patients (RIPs), while a complete pattern to gag, env and pol proteins was observed in most long-lasting infected patients (LLIPs). The median age, gender, nationality and risk transmission factors were comparable in RIPs and LLIPs. Phylogenetic analysis performed in available plasma disclosed B strains, non-B subtypes and circulating recombinant forms (CRFs) in both groups of patients, with a major presence of CRFs in non-Italian HIV subjects. The large number of patients unaware of their HIV status makes it crucial to discover hidden epidemics and implement appropriate targeted public health interventions.

Epidemiology of cytomegalovirus infection in pregnant women living in the Greater Romagna Area, Italy

<em>Background</em>. Aim of this study was to assess the incidence of Cytomegalovirus (CMV) infection in pregnant women living in Romagna area, in North East Italy to implement the best management of this infection. <br /><em>Materials</em> <em>and</em> <em>Methods</em>. In 2012, 23,727 serological tests for CMV IgG and IgM antibodies were performed in the Microbiology Unit, the Hub Laboratory of the Greater Romagna Area: 6931 were pregnant women. <br /><em>Results</em> <em>and</em> <em>Conclusions</em>. 179 subjects were positive for CMV IgM antibodies: 82 were not pregnant; 97 were IgM positive during pregnancy or in the course of a pre-conception evaluation. The detected incidence of the CMV infection in pregnancy (calculated at 1.40%) actually validates the literature data. This study’s findings clearly underline the usefulness of testing the CMV specific immune response in the pre-conception period or as early as possible during pregnancy.

Micro-endoscope for in vivo widefield high spatial resolution fluorescent imaging

In this paper we report the design, testing and use of a scannerless probe specifically for minimally invasive imaging of deep tissue in vivo with an epi-fluorescence modality. The probe images a 500 μm diameter field of view through a 710 μm outer diameter probe with a maximum tissue penetration depth of 15 mm specifically configured for eGFP imaging. Example results are given from imaging the pituitary gland of rats and zebrafish hearts with lateral resolution of 2.5 μm.

Human prolactin gene promoter regulation by estrogen: convergence with tumor necrosis factor-alpha signaling

Estrogens have been implicated in the regulation of prolactin gene expression in man, although previous studies have not defined the molecular mechanism whereby estradiol activates the human prolactin gene promoter (hPrl). We found that estradiol induced a reproducible 1.8-fold activation of the hPrl gene promoter, using pituitary GH3 cells stably transfected with a 5000-bp hPrl promoter fragment linked to luciferase reporter gene. This activation was blocked by treatment with estrogen receptor (ER) antagonists 4-hydroxytamoxifen and ICI-182,780. Promoter deletion and mutagenesis experiments identified a functional estrogen response element (ERE) sequence 1189 bp upstream of the transcription start site that was responsible for estrogen-mediated promoter activation. This site differed from the consensus ERE sequence by two base pairs, one in each half-site. This ERE was identified to be functional through binding ERalpha in EMSAs. Chromatin immunoprecipitation assays confirmed ERalpha binding to this sequence in vivo in the absence of ligand, with increased recruitment when cells were cultured in the presence of estradiol. When cells were treated with both estradiol and TNFalpha, we observed synergistic activation of the hPrl promoter, which was mediated by the -1189-bp ERE. Mutagenesis of this ERE abolished the promoter-activating effect not only of estradiol but also of TNFalpha. These data suggest a novel, promoter-specific signaling interaction between estrogen and TNFalpha signaling, which is likely to be important for prolactin regulation in vivo.

Cryptic loxP sites in mammalian genomes: genome-wide distribution and relevance for the efficiency of BAC/PAC recombineering techniques

Cre is widely used for DNA tailoring and, in combination with recombineering techniques, to modify BAC/PAC sequences for generating transgenic animals. However, mammalian genomes contain recombinase recognition sites (cryptic loxP sites) that can promote illegitimate DNA recombination and damage when cells express the Cre recombinase gene. We have created a new bioinformatic tool, FuzznucComparator, which searches for cryptic loxP sites and we have applied it to the analysis of the whole mouse genome. We found that cryptic loxP sites occur frequently and are homogeneously distributed in the genome. Given the mammalian nature of BAC/PAC genomic inserts, we hypothesised that the presence of cryptic loxP sites may affect the ability to grow and modify BAC and PAC clones in E. coli expressing Cre recombinase. We have observed a defect in bacterial growth when some BACs and PACs were transformed into EL350, a DH10B-derived bacterial strain that expresses Cre recombinase under the control of an arabinose-inducible promoter. In this study, we have demonstrated that Cre recombinase expression is leaky in un-induced EL350 cells and that some BAC/PAC sequences contain cryptic loxP sites, which are active and mediate the introduction of single-strand nicks in BAC/PAC genomic inserts.

A single strand conformation polymorphism-based carrier test for spinal muscular atrophy

Spinal muscular atrophy (SMA) is an autosomal recessive disorder with a newborn prevalence of 1 in 10,000, and a carrier frequency of 1 in 40-60 individuals. The SMA locus has been mapped to chromosome 5q11.2-13. The disease is caused by a deletion of the SMN gene, often encompassing other genes and microsatellite markers. The SMN gene is present in two highly homologous copies, SMN1 and SMN2, differing at five nucleotide positions. Only homozygous SMN1 mutations cause the disease. The sequence similarity between the SMN1 and SMN2 genes can make molecular diagnosis and carrier identification difficult. We developed a sensitive and reliable molecular test for SMN1 carrier identification, by setting up a nonradioactive single strand conformation polymorphism (SSCP)-based method, which allows for the quantification of the amount of the SMN1 gene product with respect to a control gene. The assay was validated in 56 obligate (ascertained) carriers and 20 (ascertained) noncarriers. The sensitivity of the test is 96.4%, and its specificity, 98%. In addition, 6 of 7 SMA patients without homozygous deletions presented with a heterozygous deletion, suggesting a concomitant undetected point mutation on the nondeleted SMN1 allele. Therefore, the present test is effective for detecting compound hemizygote patients, for testing carriers in SMA families, and for screening for SMA heterozygotes in the general population.

Fine mapping of the PSORS4 psoriasis susceptibility region on chromosome 1q21

Psoriasis is a chronic skin disorder affecting approximately 2% of the Caucasian population. Family clustering of the disease is well established and nonparametric linkage analyzes have mapped disease susceptibility loci on chromosomes 6p (PSORS1) and 17q (PSORS2). Nonconfirmed evidence for linkage is also available for chromosomes 2q 3q, 4q (PSORS3), 8q, 16q, and 20p. We mapped an additional susceptibility locus on chromosome 1q21 (PSORS4). In this study, we have carried out a linkage disequilibrium analysis, in order to achieve a finer localization. We recruited 79 triads from continental Italy and typed them at five loci spanning the 1.6 Mb region generating the highest multipoint LOD scores in our previous linkage study. We observed significant evidence for association with D1S2346 marker (p = 0.004). Results consistent with this data were obtained by typing an independent sample that included 28 patients and 56 controls, originating from Sardinia. In fact, p values of 0.02 were observed with both D1S2346 and D1S2715 markers. We sought further confirmation of our results by typing both samples with two novel markers (140J1C and 140J1D) flanking D1S2346. Marker 140J1D generated a p value of 0.003 in the continental Italy sample where a D1S2346/140J1D haplotype was found with a higher frequency among patients' chromosomes. Altogether our data indicate that the 1q21 susceptibility gene may be localized in the genomic interval spanned by D1S2346 and 140J1D. This report provides evidence supporting the refinement of a non-HLA psoriasis susceptibility locus.

Absence of correlation between BMP-4 polymorphism and postmenopausal osteoporosis in Italian women

Several studies have demonstrated that bone has the power of regeneration and repair. BMPs (bone morphogenetic proteins) are involved in the determination of osteoblast phenotype and bone turnover, therefore genes coding for these proteins, like BMP-4, could be considered potential candidate genes for osteoporosis. We investigated the association of BMP-4 gene polymorphism with osteoporosis in a cohort of 72 osteoporotic, postmenopausal women and 82 unrelated controls. We failed to detect any significant association between this genetic marker and the disease.

A distinctive autosomal dominant vacuolar neuromyopathy linked to 19p13

OBJECTIVE

To characterize a kindred with a distinctive autosomal dominant neuromuscular disorder.

BACKGROUND

The authors studied a large Italian family affected by a progressive neuromyopathy. Ten individuals over three generations were affected. The disease was characterized by onset from the late teens to early 50s with distal leg weakness and atrophy, development of generalized muscle weakness with distal-to-proximal progression sparing facial and ocular muscles, dysphonia and dysphagia, pes cavus and areflexia, variable clinical expression ranging from subclinical myopathy to severely disabling weakness, and mixed neurogenic and myopathic abnormalities on electromyography.

METHODS

Morphologic, immunocytochemical, and ultrastructural studies were performed in muscle biopsies from three affected patients. A genomewide linkage analysis through the genotyping of 292 microsatellite markers spanning the 22 autosomes was undertaken to map the disorder segregating in this family.

RESULTS

All muscle biopsies showed variation of fiber size, panesterase-positive angular fibers, mild to severe fibrosis, and numerous "rimmed vacuoles." Electron microscopy failed to demonstrate the nuclear or cytoplasmic filamentous inclusions specific of inclusion-body myopathies and, accordingly, immunohistochemistry did not show any positivity with SMI-31 antibodies detecting hyperphosphorylated tau. Preliminary analysis of 292 microsatellite markers provided evidence for linkage to chromosome 19p13.

CONCLUSIONS

This distinctive autosomal dominant disorder is characterized by a vacuolar neuromyopathy. Localization to chromosome 19p13 will allow the genetic relationship between this disease and inherited myopathies with rimmed vacuoles, in particular autosomal dominant inclusion-body myopathies, to be defined.

Genomic structure, promoter characterisation and mutational analysis of the S100A7 gene: exclusion of a candidate for familial psoriasis susceptibility

We have recently assigned a locus for familial psoriasis (PS) susceptibility to the region containing the epidermal differentiation complex gene cluster on chromosome 1q21. Gene S10OA7 maps within this cluster and is reported to be markedly over-expressed in the skin lesions of psoriatic patients. In order to analyse S100A7 as a candidate for PS susceptibility, we have determined its genomic structure regarding exon-intron boundaries and the transcription start site. The gene is organised in three exons and two introns, spanning 2.7 kb. The 5' flanking region contains AP1- and Sp1-binding motifs and a TATA box. We have performed functional assays by using the beta-galactosidase gene as a reporter and have confirmed that this region has strong promoter activity. To search for nucleotide variation within S100A7, we have designed a set of primers to amplify each exon and the gene promoter. Polymerase chain reaction products from 15 unrelated PS patients selected from 1q-linked pedigrees and 25 normal controls have been characterised by single-strand conformation polymorphism and direct sequencing techniques. These analyses have revealed the presence of two polymorphisms in the promoter region (-559G/A and -563 A/G), neither of which shows preferential association with the disease. Our results indicate that S100A7 can be excluded as a candidate for PS susceptibility.

Searching for psoriasis susceptibility genes in Italy: genome scan and evidence for a new locus on chromosome 1

Psoriasis is a chronic inflammatory dermatitis, affecting approximately 2% of the population. Major clinical features include red, scaly patches on scalp, elbows, and knees, with or without severe arthritis. Several putative susceptibility loci have been mapped by parametric and non-parametric linkage analysis to chromosome regions 2p, 4q, 6p, 8q, 16q, 17q, and 20p; however, the most significant results and confirmation of linkage are only available for the 17q and 6p chromosome regions at present. In this study, 22 multiplex Italian families were investigated for linkage to 6p and 17q susceptibility regions, using a set of four microsatellites. These analyses failed to detect significant linkage with any of the examined markers. A genome-wide scan was then performed on one of the largest pedigrees, searching for an additional susceptibility locus. This study disclosed a putative linkage to chromosome 1cen-q21 markers. When these microsatellites were analyzed in the remaining families of the sample, a significant linkage was observed using both parametric and non-parametric methods. The highest two-point lod score value was obtained with D1S305 marker (3.75 at 0 = 0.05). Non-parametric analysis at this locus also demonstrated a significant excess of allele sharing (p = 0.0001).

A possible role of NAIP gene deletions in sex-related spinal muscular atrophy phenotype variation

Childhood SMAs are common neuromuscular disorders, due to the occurrence of large genomic deletions encompassing the SMN gene and often extending to involve the NAIP gene. Although NAIP deletions are more frequently observed in patients affected by the acute form of the disease, it is not possible to establish an unambiguous correlation between deletion size and clinical severity. We have investigated the effects of gender on the association between NAIP gene deletion and disease severity. NAIP deletions were screened in 197 Italian SMA patients lacking SMN; the results obtained were correlated with disease severity in male and female samples separately. No significant relationship between deletion size and clinical phenotype was observed among male subjects, whereas in females the absence of NAIP was strongly associated with a severe phenotype (p <0.0001). These results provide a possible molecular explanation for the sex-dependent phenotype variation observed in SMA patients.