Recommendations for the Use of Tryptase in the Diagnosis of Anaphylaxis and Clonal Mastcell Disorders.

Summary: Tryptase is a serin-protease produced and released by mast cells after IgE-mediated or non-IgE mediated stimuli. We here review the various aspects related to the molecular characteristics of the enzyme and its biological effects, the genetic basis of its production and the release kinetics. Recommendations for the clinical use of tryptase measurement developed by a task force of Società Italiana di Patologia Clinica e Medicina di Laboratorio and Associazione Allergologi Immunologi Italiani Territoriali e Ospedalieri are given on the best procedure for a correct definition of the reference values in relation to the inter-individual variability and to the correct determination of tryptase in blood and other biological liquids, in the diagnosis of anaphylaxis (from drugs, food, insect sting, or idiophatic), death from anaphylaxis (post mortem assessment) and cutaneous or clonal mastcell disorders.

IgE sensitization to Anisakis pegreffii in Italy: Comparison of two methods for the diagnosis of allergic anisakiasis.

IgE sensitization to Anisakis pegreffii in Italian subjects suffering from gastro-allergic anisakiasis (GAA) (N=5), or showing chronic urticaria (CU+) after fish consumption (N=100), was investigated. A control group (N=5) was also included. IgE response was analysed by immunoblotting (WB) assay, using both excretory/secretory products (ESPs) and crude extract (CE) of A. pegreffii larvae. The results were compared with those achieved by the conventional immunological method for Anisakis allergy (ie, immunoCAP). Among the 110 subjects, 28 showed IgE positivity with both WB and iCAP methods; 13 proved IgE reactivity, in WB assay, to ESP antigens of A. pegreffii, here provisionally indicated as Ani s 1-like, Ani s 7-like, Ani s 13-like; only 15 sera have shown IgE-WB reaction to Ani s 7-like and Ani s 13-like. iCAP and WB exhibited a high concordance value (κ=1.00) when iCAP value was <0.35 (negative result) and >50.0 (positive result). In the sera samples recorded as positive to Anisakis allergy, Ani s 1-like was responsible for 46.4% of the sensitivity, while Ani s 7-like and Ani s 13-like for 100%. They could be considered as major antigens in the diagnosis of allergic anisakiasis caused by A. pegreffii.

Correlation between gamma glutamyltransferase fractions and bone quality.

Gamma-glutamyltransferase (GGT) has been recently identified as a bone-resorbing factor. The aim of this study was to investigate the association between plasma GGT fractions levels and bone quality. Plasma GGT fractions were analysed by gel-filtration chromatography. Bone quality was established quantitatively by two micro-CT derived microarchitectural parameters: the BV/TV (mineralised bone volume/total volume), and the SMI (structure model index) that describes the rod-like (low resistant) or plate-like (high-resistant) shape of bone trabeculae. We enrolled 93 patients hospitalised for elective total hip replacement (group Arthrosis, n=46) or for proximal femoral fracture (group Fracture, n=47). Patients within the first quartile of BV/TV (Q1, osteoporotic patients, n=6) showed higher levels of b-GGT fraction [median (min-max): 3.37 (1.42­6.81)] compared to patients with normal bone density (fourth quartile Q4, n=10; 1.40 (0.83­4.36); p=0.0393]. Also, according to SMI, b-GGT value was higher in the subgroup with bone fragility [Q1, n=8: 1.36 (0.43­4.36); Q4, n=8: 5.10 (1.4 ­7.60); p=0.0117]. In conclusion, patients characterised by fragile bone structure showed specifically higher levels of plasma b-GGT activity thus suggesting fractional GGT analysis as a possible biomarker in the diagnosis of osteoporosis.

Stimulation of TH1 response by Helicobacter pylori neutrophil activating protein decreases the protective role of IgE and eosinophils in experimental trichinellosis.

Th2 responses seem to play an important role in defence against Trichinella spiralis (Ts). The neutrophil Activating protein of Helicobacter pylori (HP-NAP), that induces IL-12, and IL-23 expression and shifts to Th1 allergen-specific Th2 cells in vitro was used as an anti-Th2 agent in BALB/c mice infected with T. spiralis. The muscle larvae (ML) burden was lower (p < 0.02) in untreated infected animals than those infected treated with HP-NAP. In both groups there was an inverse relationship between ML burden of each animal and total IgE level (controls: r -0.617, p = 0.0013 and HP-NAP-treated: r -0.678, p = 0.0001) or eosinophil count, evaluated in the same mouse on day 42 (r -0.390, p = 0.0592 and r -0.803, p = 0.0001, respectively). Inflammatory response around the nurse cell-parasite complex was significantly higher in HP-NAP-treated infected animals than in those untreated infected, on the contrary the number of eosinophils, counted around each complex was significantly lower in the first animal group. This study provides evidence of a powerful anti-Th2 activity in vivo by HP-NAP and for the partial protective effect of Th2 responses in T. spiralis infection.

Salvage of an Octogenarian Liver Graft Using Normothermic Perfusion: A Case Report.

Liver transplantation with very old donors is safe, but is associated with an increased incidence of ischemic-type biliary lesions and delayed graft function. Normothermic machine perfusion (NMP) is a novel technique for preservation of liver grafts and has the potential to reduce ischemia-reperfusion injury. A case is reported here of a liver transplantation (LT) with a graft from an 83-year-old brain-dead donor. Procurement was with dual perfusion and en bloc, modified fast technique. Donor kidneys were not transplanted due to severe atherosclerosis and poor perfusion. The liver was shipped to the transplantation center and underwent NMP with a blood-based perfusate. During machine perfusion lactates decreased, vascular flow was stable, and bile production restored, and the graft was considered suitable for transplantation. The postoperative course was uneventful and 4 months after surgery the patient is in good clinical condition with normal liver function. To date, few LTs have been performed with NMP in humans, but its preliminary results are promising. NMP allows functional evaluation of the graft and possibly reduction of post-transplantation complications when extended-criteria donor grafts are used.

PADI4 gene in multiple sclerosis: a family-based association study.

In multiple sclerosis (MS) MBP is heavily citrullinated by peptidylarginine deiminase (PAD). This post-translational modification may be crucial for its pathogenesis. PADI4 is the isoform expressed in inflammatory infiltrates. The aim of this study was to analyse the role of PADI4 gene in conferring susceptibility to MS, by means of a family-based association study, testing three SNPs by RFLP. No association was found either with single SNPs or haplotypes. Similarly no significant association was detected partitioning the patients according to DRB1*15 positivity or disease severity. These results do not support a major role of the PADI4 gene, but further studies may contribute to clarify the genetic factors that regulate deimination.

Autoantibodies directed against ribosomal P proteins: use of a multiple antigen peptide as the coating agent in ELISA.

Autoantibodies directed against the ribosomal proteins P0, P1 and P2 (P proteins) are specific for systemic lupus erythematosus (SLE) and there are some evidences that they could be related to the neuropsychiatric manifestations of the disease. In this study, a multiple antigen peptide (MAP) carrying four copies of the C-terminal peptide (13 residues) of the P2 protein, which is a common epitope of the three P proteins, was prepared for use in an ELISA assay. It was employed to detect antibodies directed against the ribosomal P proteins in 102 SLE patients and the results were compared with those obtained using immunoblotting (IB). With this new ELISA, antiribosomal P protein antibodies were found in 15/102 SLE sera. These results correlated well with the results of IB. Furthermore, we confirmed that naturally occurring antiribosomal P protein antibodies are directed mainly against the epitope containing the C-terminal sequence and shared by the three P proteins. MAP appears to be an excellent coating agent for ELISA assays designed to detect anti-P antibodies. Further experiments showed the superiority of MAP, compared to the free peptide, in the detection of weakly positive sera. This ELISA can also be used for the serological follow-up of SLE patients.

The cross-reactivity of autoantibodies in connective tissue diseases.

This paper analyses various factors involved in the determination of the cross-reactivity of autoantibodies in connective tissue diseases. We report the results of various studies of antigens and antibodies relating to this topic, and consider the possible role of cross-reactivity in the pathogenesis of some of the clinical manifestations of systemic autoimmune diseases.

Activity criteria in systemic lupus erythematosus.

Several clinical indices have been proposed to measure disease activity in systemic lupus erythematosus (SLE), a disorder characterised by alternate phases of flare and remission. Over the last 5 years a European multicenter study was carried out in order to reach a consensus on the definition of SLE activity. A new index, ECLAM (European Consensus Lupus Activity Measurement), was created and then validated in the first and in the second parts of the study, respectively. In addition, a comparison between ECLAM and the other most commonly used lupus activity indices was performed. ECLAM appeared to be the best activity index for classifying lupus patients, whether used as a single state index (i.e., to measure activity at a given moment in time) or as a transition index. (i.e., to measure variations in activity over time).

Detection of anti-ribosome antibodies: a long story of lights and shadows.

Circulating autoantibodies against ribosomal proteins characterise a subset of patients with systemic lupus erythematosus. Following the identification of three phosphorylated proteins as the main ribosomal autoantigens recognised by these autoantibodies, several studies have been carried out in the last decade to set up a reliable and sensitive method of detecting anti-ribosome autoantibodies and disclosing their possible clinical relevance in the diagnosis and monitoring of symptoms and signs of the disease. Although a number of clinical associations have been proposed, contrasting results have emerged from these investigations. This review analyses the methodological problems linked with the various techniques used to detect anti-ribosome antibodies and provides a critical update of the clinical associations described in lupus patients to date.

Hunter syndrome (Mucopolysaccharidosis type II), severe phenotype: long term follow-up on patients undergone to hematopoietic stem cell transplantation.

AIM: Our study aim is the evaluation of long-term effects of hematopoietic stem cell transplantation on Italian patients with severe Hunter syndrome. METHODS: Four boys, suffering from Hunter syndrome, severe phenotype, received hematopoietic stem cell transplantation between 2 years 6 months and 2 years 11 months of age, from 1992 to 2001. A complete multidisciplinary evaluation of hematopoietic stem cell transplantation long-term effects was performed periodically. RESULTS: All patients achieved successful engraftment. Urine glycosaminoglycans excretion was reduced or normalized, and the activity of leukocyte iduronate-2-sulphatase enzyme, absent before hematopoietic stem cell transplantation, remained constant, in all patients. Dysostosis multiplex progressed over time, according to the natural evolution of the disease. Joint stiffness improved in all affected districts. Hepatosplenomegaly decreased until it disappeared. The cardiovascular involvement stayed unchanged, as well as hearing loss. Skin became hyperelastical; face features seemed less coarse if compared to the natural evolution of the disease. Cerebral white matter alterations were constant in time. On the contrary, the hematopoietic stem cell transplantation did not prove to have long-term effectiveness on neurological symptoms of Hunter syndrome. CONCLUSION: The hematopoietic stem cell transplantation was successful in slowing the progression of Hunter syndrome, and even the evolution of neurological feature of the disease was slower in the first years after this treatment.

Antibodies directed against ribosomal P proteins cross-react with phospholipids.

Anti-ribosomal P protein (anti-P) antibodies are marker antibodies in systemic lupus erythematosus (SLE). Their association with psychiatric or neurological manifestations has been proposed, but remains controversial. Anti-phospholipid antibodies are the hallmark of a syndrome that may comprise a number of neurological manifestations. Thus, anti-P and anti-phospholipid antibodies have both been associated with central nervous system involvement and their co-existence in the same sera was reported. We verified the ability of purified anti-P antibodies to bind different phospholipids and phospholipid-binding proteins in solid-phase assays. Anti-P antibodies from five of eight patients bound cardiolipin (CL) when saturated with fetal calf serum (FCS); in three cases anti-CL antibodies were also detected in the flow-through. No anti-P eluate, nor any corresponding flow-through, bound beta(2)-glycoprotein I alone or prothrombin. Moreover, no anti-P eluate bound CL when the plates were blocked with bovine serum albumin in the absence of FCS. Anti-P antibodies with anti-CL activity bound both ssDNA and dsDNA and also nucleosomes in three patients. Our data indicate a great heterogeneity of anti-P antibodies that appear to be overlapped partially with the other autoantibody populations detected frequently in SLE.

A family based study shows no association between rheumatoid arthritis and the PADI4 gene in a white French population.

BACKGROUND: Autoantibodies to citrullinated proteins (ACPA) are considered a specific marker for rheumatoid arthritis. Peptidylarginine deiminase (PAD) is the enzyme that converts arginyl into citrullyl residues; different isoforms of the enzyme are expressed in mammals. It has been suggested that the PADI4 gene may contribute to genetic susceptibility to rheumatoid arthritis, but conflicting results have been obtained in different populations. OBJECTIVE: To test the hypothesis that the PADI4 gene may confer susceptibility to rheumatoid arthritis in a white French population, using powerful and highly reliable family based association tests. METHODS: DNA samples were analysed from 100 families where one member was affected by rheumatoid arthritis and both parents were available for sampling. Five single nucleotide polymorphisms, located within the PADI4 gene and in its close proximity, were genotyped by restriction fragment length polymorphism, and haplotypes were constructed. The analysis involved use of the transmission disequilibrium test and genotype relative risk. ACPA were detected by ELISA on cyclic citrullinated peptides and on human deiminated fibrinogen. RESULTS: No single SNP or haplotype was associated with the disease, or was preferentially transmitted. No association was found when patients were partitioned according to ACPA positivity. CONCLUSIONS: No PADI4 haplotype is associated with rheumatoid arthritis in a white French population. The role of genes encoding the other PAD isoforms, or modulating tissue expression or enzyme activity, remains to be elucidated.

Anti-ribosomal antibodies bind the Sm proteins D and B/B'.

In order to analyse the specificity of human anti-ribosomal P protein antibodies, anti-ribosomal P protein antibodies were affinity-purified from the sera of lupus patients. Their binding capacity towards recombinant SmD protein and recombinant SmB/B' protein was evaluated by immunoblot and ELISA. Epitope mapping of SmD was performed by means of synthetic peptides. Anti-ribosomal P protein antibodies bound recombinant SmD (5/10) and SmB/B' (4/10) on immunoblot; 6/10 showed binding capacity to SmD on ELISA. Inhibition experiments using ELISA confirmed the specificity of this binding. Our data indicate the cross-reactivity of spontaneously developed anti-ribosomal P protein antibodies with the B/B' and D constituents of the Sm complex. The coexistence of anti-Sm and anti-ribosomal antibodies in lupus sera may therefore be due, at least in part, to the reactivity of a single autoantibody population.

Anti-ribosomal antibodies from lupus patients bind DNA.

Antibodies specific for ribosomal P proteins (anti-P) are a hallmark of systemic lupus as anti-DNA antibodies are. It has been reported that anti-P antibodies are more frequently detected in anti-dsDNA positive sera. The aim of the present study was to verify the binding ability of anti-P antibodies towards polynucleotides and nucleosomes. We purified anti-P antibodies from 8 SLE patients' sera and we analysed them by ELISA on plates coated with DNA or nucleosomes. We performed also inhibition experiments in order to verify the specificity of the binding. All the purified anti-P antibodies bound DNA, but some anti-DNA binding activity remained among the non-anti-P antibodies in the flow through. Only half of the purified antibodies bound to nucleosomes, and anti-nucleosomal activity was demonstrated also in non anti-P antibody fraction. The inhibition experiments performed on two anti-P antibodies pointed out that only the homologous antigen inhibited the binding to either P peptide or DNA coated onto the solid phase. These results show that sera in which the two specificities coexist contain antibodies endowed with a double binding ability for DNA and the P peptide.

Clinical and serological associations of ribosomal P autoantibodies in systemic lupus erythematosus: prospective evaluation in a large cohort of Italian patients.

OBJECTIVE: To verify the association of ribosomal anti-P antibodies (anti-P), as detected by a sensitive ELISA, with serological findings and clinical manifestations, including neuropsychiatric involvement evaluated according to the American College of Rheumatology (ACR) nomenclature, in a large cohort of patients with systemic lupus erythematosus (SLE). METHODS: Anti-P were evaluated in the serum of 149 consecutive Italian SLE patients by an ELISA using a multiple antigen peptide carrying four copies of a common P0, P1 and P2 epitope. A complete laboratory evaluation and clinical examination were performed in each patient. In addition, all patients underwent an accurate neuropsychiatric and neuropsychological assessment performed by trained specialists according to the 1999 ACR suggestions. RESULTS: Serum anti-P were detected in 18/149 patients (12.1%). The anti-P prevalence was similar (11.7%) when the analysis was performed in a larger series of sera including 82 additional SLE patients, who were not included in the clinical study. The age of anti-P-positive patients at disease onset was less than 33 yr and, in comparison with the anti-P-negative patients, these patients showed more active disease activity and a higher prevalence of photosensitivity and malar and discoid rash. A strong association between IgG anticardiolipin antibodies and anti-P was also found. However, anti-P were associated with neither neuropsychiatric syndromes nor cognitive impairment. CONCLUSION: This study does not seem to confirm the described association of anti-P with SLE neuropsychiatric manifestations. However, it supports the anti-P association with different skin manifestations as well as the presence of anticardiolipin in a subset of patients with SLE characterized by early disease onset.