Type I interferon pathway activation across the antiphospholipid syndrome spectrum: associations with disease subsets and systemic antiphospholipid syndrome presentation.

Introduction: While the type I interferon (IFN-I) pathway is crucial in autoimmunity, its role in antiphospholipid antibody (aPL)-positive subjects, including aPL carriers and antiphospholipid syndrome (APS) patients, is poorly understood. This study aims at characterizing IFN-I pathway activation within the spectrum of aPL-positive subsets. Methods: A total of 112 patients [29 aPL carriers, 31 primary APS (PAPS), 25 secondary APS (SAPS), 27 systemic lupus erythematosus (SLE) patients without aPL, and 44 healthy controls (HCs)] were recruited. IFI6, IFI44, IFI44L, MX1, IFI27, OAS1, and RSAD2 gene expression was evaluated in whole blood, and a composite index (IFN score) was calculated. Results: An overall activation of the IFN-I pathway was observed across the entire APS spectrum, with differences among genes based on the specific disease subset. The composite score revealed quantitative differences across subsets, being elevated in aPL carriers and PAPS patients compared to HCs (both p < 0.050) and increasing in SAPS (p < 0.010) and SLE patients (p < 0.001). An unsupervised cluster analysis identified three clusters, and correspondence analyses revealed differences in clusters usage across APS subsets (p < 0.001). A network analysis revealed different patterns characterizing different subsets. The associations between IFN-I pathway activation and clinical outcomes differed across APS subsets. Although no differences in gene expression were observed in systemic APS, the network analyses revealed specific gene-gene patterns, and a distinct distribution of the clusters previously identified was noted (p = 0.002). Conclusion: IFN-I pathway activation is a common hallmark among aPL-positive individuals. Qualitative and quantitative differences across the APS spectrum can be identified, leading to the identification of distinct IFN-I signatures with different clinical values beyond traditional categorization.

Pediatric Presentation of Antiphospholipid Syndrome: A Review of Recent Literature With Estimation of Local Prevalence.

We aimed to investigate the epidemiology, the clinical and laboratory characteristics of the pediatric involvement of antiphospholipid syndrome (APS), by performing a review of the current evidence and reviewing local experience in the Northwest Italy. To achieve this, we performed a detailed literature search to identify articles describing clinical and laboratory characteristics of pediatric APS. In concomitance, we conducted a registry-based study collecting data from the Piedmont and Aosta Valley Rare Disease Registry including pediatric patients diagnosed with APS in the last 11 years. The literature review led to inclusion of six articles with a total of 386 pediatric patients (65% females, 50% with systemic lupus erythematosus (SLE) as concomitant diagnosis). Rates of venous and arterial thrombosis were 57 and 35%, respectively. "Extra-criteria manifestations" included mostly hematologic and neurologic involvement. Almost one-quarter of patients (19%) reported recurrent events and 13% manifested as catastrophic APS. A total of 17 pediatric patients (mean age 15.1 ± 2.8, 76% female) developed APS in the Northwest of Italy. In 29% of cases, SLE was a concomitant diagnosis. Deep vein thrombosis was the most frequent manifestation (28%) followed by catastrophic APS (6%). The estimated prevalence of pediatric APS in Piedmont and Aosta Valley Region is 2.5/100,000 people, whereas the estimated annual incidence is 0.2/100,000 inhabitants. In conclusion, clinical manifestations of pediatric APS seem to be more severe and with a high prevalence of noncriteria manifestations. International efforts are needed to better characterize this condition and to develop new specific diagnostic criteria to avoid missed/delayed diagnosis in children with APS.

Safety and efficacy of pre-exposure prophylaxis with tixagevimab/cilgavimab (Evusheld) in patients with glomerular diseases who received rituximab.

Background: Patients on B-cell-depleting agents may have a suboptimal response to vaccination, placing them at a higher risk of contracting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or suffering from a more severe prognosis. Indeed, available data on pre-exposure prophylaxis with tixagevimab/cilgavimab (Evusheld) in subjects with glomerular diseases (GDs) who received rituximab are limited. Methods: We conducted a prospective study analysing the safety and efficacy of tixagevimab/cilgavimab for pre-exposure prophylaxis in patients with GDs who received rituximab in the previous 12 months. The rates of symptomatic infections and hospitalizations were compared with those for patients with GD treated with rituximab who refused to receive tixagevimab/cilgavimab. Results: Tixagevimab/cilgavimab was administered to 22 patients (12 females, mean age 58.4 ± 19.6 years) with GD diagnoses including membranous nephropathy, lupus nephritis, anti-neutrophil cytoplasmic antibody-associated vasculitis and focal segmental glomerulosclerosis. No patient treated with tixagevimab/cilgavimab experienced symptomatic infection with SARS-CoV-2 during the follow-up (mean observation time of follow-up was 112 ± 23 days), while 11 of 28 controls (39.3%) reported a symptomatic infection (P = .0001), requiring hospitalization in 2 cases. Reported adverse events were mild, namely self-limiting headache [4], discomfort at the injection site [3], flu-like symptoms/myalgia [3] and fever [1]. No serious adverse events (e.g. cardiac events, anaphylaxis) were reported. Conclusion: Pre-exposure prophylaxis with tixagevimab/cilgavimab seems safe and lowered the risk of symptomatic SARS-CoV-2 infection by ≈40% in vaccinated subjects with GD who received anti-CD20 therapy. Possible applications in the subset of patients who need immunosuppressive therapy, especially with rituximab, in a pandemic setting might be envisaged.

New Frontiers in Autoimmune Diagnostics: A Systematic Review on Saliva Testing.

(1) Background: Immunological laboratory testing is known to be complex, and it is usually performed in tertiary referral centers. Many criticalities affect diagnostic immunological testing, such as limited availability, the need for specifically trained laboratory staff, and potential difficulties in collecting blood samples, especially in the most vulnerable patients, i.e., the elderly and children. For this reason, the identification of a new feasible and reliable methodology for autoantibody detection is urgently needed. (2) Methods: We designed a systematic review to investigate the available literature on the utilization of saliva samples for immunological testing. (3) Results: A total of 170 articles were identified. Eighteen studies met the inclusion criteria, accounting for 1059 patients and 671 controls. The saliva collection method was mostly represented by passive drooling (11/18, 61%), and the most frequently described methodology for antibody detection was ELISA (12/18, 67%). The analysis included 392 patients with rheumatoid arthritis, 161 with systemic lupus erythematosus, 131 with type 1 diabetes mellitus, 116 with primary biliary cholangitis, 100 with pemphigus vulgaris, 50 with bullous pemphigoids, 49 with Sjogren syndrome, 39 with celiac disease, 10 with primary antiphospholipid syndromes, 8 with undifferentiated connective tissue disease, 2 with systemic sclerosis, and 1 with autoimmune thyroiditis. The majority of the reviewed studies involved adequate controls, and saliva testing allowed for a clear distinction of patients (10/12 studies, 83%). More than half of the papers showed a correlation between saliva and serum results (10/18, 55%) for autoantibody detection, with varying rates of correlation, sensitivity, and specificity. Interestingly, many papers showed a correlation between saliva antibody results and clinical manifestations. (4) Conclusions: Saliva testing might represent an appealing alternative to serum-based testing for autoantibody detection, considering the correspondence with serum testing results and the correlation with clinical manifestations. Nonetheless, standardization of sample collection processing, maintenance, and detection methodology has yet to be fully addressed.

Chasing the Zebra: a case of membranous-like Glomerulopathy with SSA/RO52 deposits and no overt connective tissue disease.

BACKGROUND: The nature of the deposits in immune-mediated glomerulonephritis with a membranous pattern and masked IgG-Kappa deposits (MGMID) remains still to be elucidated. CASE PRESENTATION: We present a case of 33-year-old woman developing a continuous asymptomatic proteinuria (0.8-1 g/24 h) with no overt connective tissue diseases. She tested positive at high titers for SSA antibodies (Ro52 838 UI/mL, Ro60 2716 UI/mL) and at the kidney biopsy histological findings were compatible with an immune-mediated glomerulonephritis with a membranous pattern and masked IgG-Kappa deposits. Also, we demonstrated a positive immunohistochemistry staining for anti-Ro52-SSA antibodies, with a granular positivity in mesangium and along rare glomerular capillaries. To date, only one case of a patient with overt diagnosis of Sjögren's syndrome with MGMID has been described but a pathogenic role for SSA and SSB antibodies has never been proven. CONCLUSIONS: In this case, we described for the first time by immunohistochemistry a Ro52+ granular positivity in the mesangium and glomerular capillaries, potentially paving the way for a better understanding of MGMID.

Finding the Needle in the Haystack: Serological and Urinary Biomarkers in Behçet's Disease: A Systematic Review.

Urinary and serological markers play an essential role in the diagnostic process of autoimmune diseases. However, to date, specific and reliable biomarkers for diagnosing Behçet's disease (BD) are still lacking, negatively affecting the management of these patients. To analyze the currently available literature on serological and urinary BD biomarkers investigated in the last 25 years, we performed a systematic literature review using the Population, Intervention, Comparison, and Outcomes (PICO) strategy. One hundred eleven studies met the eligibility criteria (6301 BD patients, 5163 controls). Most of them were retrospective, while five (5%) were prospective. One hundred ten studies (99%) investigated serological biomarkers and only two (2%) focused on urinary biomarkers. One hundred three studies (93%) explored the diagnostic potential of the biomolecules, whereas sixty-two (56%) tested their effect on disease activity monitoring. Most articles reported an increase in inflammatory markers and pro-oxidant molecules, with a decrease in antioxidants. Promising results have been shown by the omics sciences, offering a more holistic approach. Despite the vast number of investigated markers, existing evidence indicates a persistent gap in BD diagnostic/prognostic indices. While new steps have been taken in the direction of pathogenesis and disease monitoring, international efforts for the search of a diagnostic marker for BD are still needed.

Open-label, prospective, phase II descriptive pilot trial of belimumab therapy for refractory and/or non-criteria manifestations of antiphospholipid syndrome: study protocol.

OBJECTIVES: To evaluate the safety and tolerability of belimumab given for 24 months in patients persistently positive for antiphospholipid antibodies (aPL) with clinical features attributable to aPL [refractory and/or non-criteria manifestations of the antiphospholipid syndrome (APS)]. METHODS: In this investigator-initiated, single-centre, open-label, prospective, phase II descriptive pilot trial, belimumab will be administered in 15 patients attending San Giovanni Bosco Hospital (Turin) showing refractory and/or non-criteria manifestations of APS. Subjects will receive belimumab 10 mg/kg intravenously (in addition to their ongoing APS treatment) with regimen at 0, 2, 4 weeks and every 4 weeks thereafter (up to week 104). Study endpoints determined at 4, 16, 24, 36, 52 and 104 weeks will include: primary (safety and adverse events) and secondary outcomes, such as changes in clinical outcomes (recurrent thromboses, thrombocytopenia, haemolytic anaemia, cardiovascular events, skin ulcer, aPL-related nephropathy and cognitive dysfunction), laboratory outcomes (routine tests, aPL, ENA and anti-dsDNA tests, thrombin generation assay, interferon-signature analysis, lymphocytes immunophenotyping, BLyS determination) and QoL evaluation. RESULTS: Study endpoints determined at 4, 16, 24, 36, 52 and 104 weeks will include: primary (safety and adverse events) and secondary outcomes, such as changes in clinical outcomes (recurrent thromboses, thrombocytopenia, haemolytic anaemia, cardiovascular events, skin ulcer, aPL-related nephropathy and cognitive dysfunction), laboratory outcomes (routine tests, aPL, ENA and anti-dsDNA tests, thrombin generation assay, interferon-signature analysis, lymphocytes immunophenotyping, BLyS determination) and QoL evaluation. CONCLUSIONS: Targeting B-cells is emerging as an appealing strategy for patients with APS. Preliminary observations showed aPL negativisation after starting therapy with belimumab. The clinical relevance of these findings will be investigated in this prospective study. If confirmed, the current 'anti-thrombotic' approach to APS patients could be complemented, at least in selected cases, with an 'immunomodulatory' strategy.

Thrombin generation assay and lupus anticoagulant synergically distinguish populations of patients with antiphospholipid antibodies.

AIM: To apply thrombin generation assay (TGA) in a large cohort of antiphospholipid antibodies (aPL)-positive patients. MATERIAL AND METHODS: 108 patients were tested with TGA and lupus anticoagulant (LA) testing and divided according to their aPL profile. Briefly, 21 patients were positive for anti-phosphatidylserine (aPS)/prothrombin (PT) IgG/IgM (group1), 29 for anti-ß2-glycoprotein-I (aß2GPI) and anti-cardiolipin (aCL) IgG/IgM (group2), 31 for aPS/PT, aß2GPI and aCL IgG/IgM (group3), 27 for aPS/PT and/or aß2GPI+aCL IgM at low-titres (group4). 31 healthy donors (HDs) and 24 controls treated with vitamin K antagonists (VKA) were included. RESULTS: The most deranged TGA and LA profiles were observed in tetra-positive patients (group3) that differed significantly to the other groups, thus those with isolated, double or triple aPL-positivity. Moreover, when comparing the TGA profile of all antiphospholipid syndrome (APS) patients, aPL-carriers, HDs and VKA controls, we observed that the aPL+ patients (especially APS) showed a distinctive profile that allowed to distinguish them from the other groups with significantly higher tLag and tPeak, and lower Peak and area under the curve.When focusing on APS clinical manifestations, patients with a high-risk profile (group3) showed significant differences from those presenting low-titres aPL (group 4) regarding the number of venous events (p=0.04), recurrence of any thrombotic event (p=0.01), of arterial events (5 vs 0, p=0.02), the occurrence of TIA (p=0.04), DVT (p=0.02) and, when analysing extracriteria manifestations, of peripheral artery disease (p=0.04). CONCLUSIONS: TGA seems a valuable approach to stratify aPL+ patients according to their risk profile. The differences among different populations of autoantibodies specificities could be considered a translational validation of the increased thrombotic risk of patients with triple or tetra aPL-positivity.

Genetic Testing for a Patient with Suspected 3 Beta-Hydroxysteroid Dehydrogenase Deficiency: A Case of Unreported Genetic Variants.

3beta-hydroxysteroid dehydrogenase type II deficiency (HSD3B2 deficiency), a rare form of congenital adrenal hyperplasia (CAH), is characterized by varying degrees of salt loss and incomplete masculinization in males and mild virilization or normal external genitalia in females. We report the case of a patient (46XY) showing salt loss and incomplete masculinization, markedly elevated levels of 17OHP (17 hydroxyprogesterone), ACTH (Adreno Cortico Tropic Hormone), testosterone and delta4androstenedione (delta4A), low levels of cortisol and absence of bone skeletal alterations that frequently characterize POR (Cytochrome P450 oxidoreductase) deficiency. Mutation analysis by Sanger sequencing of the HSD3B2 gene showed that the patient presented with a compound heterozygote for two novel variants c.370A>G p.Ser124Gly and c.308-6 G>A. The two HSD3B2 gene variants were also present in the patient's older brother showing only incomplete masculinization. The in silico analysis revealed a probable damaging effect of c.370A>G p.Ser124Gly: residue p.Ser124 is highly conserved among species and seems to be located in the catalytic site of the enzyme, playing a pivotal role in NAD(H) binding to its substrate. Intronic c.308-6G>A variant is predicted to be likely pathogenic; the substitution seems to cause a change in the splice acceptor site located 6bp downstream of the variant. The two siblings seem to be affected by 3ß-HSD2 deficiency; nevertheless, the two novel variants are likely to cause variable expressivity of the disease.

Dickkopf Homolog 3 (DKK3) as a Prognostic Marker in Lupus Nephritis: A Prospective Monocentric Experience.

Background: The gold standard for diagnosis of lupus nephritis (LN) is still represented by renal biopsy, and serological prognostic biomarkers are still lacking. Dickkopf homolog-3 (DKK3) has been suggested as a marker of tissue fibrosis in different conditions; however, its role in autoimmune diseases needs to be elucidated. Here, we investigated the prognostic role of DKK3 in systemic lupus erythematosus (SLE) patients with and without LN, assessing its changes in relation to kidney function, flares, and interstitial fibrosis. Methods: Overall, 132 SLE patients (57 with LN) were included and prospectively followed up for at least 36 months. DKK3 was measured in serum at baseline. Biopsies were evaluated for glomerular involvement, interstitial fibrosis, and tubular atrophy. Results: Patients with biopsy-proven LN had significantly higher levels of DKK3 than those without (median [min−max]: 215 ng/mL [81−341] vs. 21.1 ng/mL [1−69], p < 0.01). DKK3 levels were associated with prevalent chronic kidney diseases (OR: 4.31 [C.I. 2.01−6.61] per DKK3 doubling, p < 0.01), higher chronicity index at biopsy (1.75 [1.51−2.77] per DKK3 doubling, p < 0.01), and flares rate (OR: 1.45 [C.I. 1.1−5.71] per DKK3 doubling, p < 0.044). Conclusions: While kidney biopsy still represents the gold standard for diagnostic and prognostic assessment in LN, DKK3 could represent an additional prognostic tool to monitor SLE patients and guide therapeutic choices.

Assessing the cardiovascular risk in patients with systemic lupus erythematosus: QRISK and GAPSS scores head-to-head.

OBJECTIVES: We aimed to apply and compare the QRISK3 and the adjusted Global AntiPhospholipid Syndrome (APS) Score (aGAPSS) in a cohort of systemic lupus erythematosus (SLE) patients, with and without a concomitant diagnosis of APS, in order to assess their augmented risk of developing cardiovascular diseases (CVDs). METHODS: Patients (25-85 yo) with a diagnosis of SLE and/or of Secondary APS (SAPS) were included. QRISK3 was calculated using the official online calculator; aGAPSS using the validated point-values based on aPL-profile and independent risk factors. RESULTS: The cohort included 142 SLE patients: 34 SAPS (23.9%) and 108 SLE patients without APS (76.1%).When considering all the cohort, patients with cerebrovascular/coronary events showed higher values of aGAPSS (10.1 ± 6.2 vs. 5.8 ± 6.1; p = 0.007), but not of the QRISK3. Furthermore, a significant association was observed between the occurrence of these events and high-risk aGAPSS: p = 0.03 for aGAPSS≥8, p = 0.01 for aGAPSS ≥9, p = 0.008 for aGAPSS ≥10. aGAPSS strongly correlated with the occurrence of any thrombotic event, both at the uni- and multivariate analysis (p = 0.012 and p = 0.009). Male gender also resulted to positively correlate with the occurrence of any thrombotic event at both uni- and multivariate analysis (p = 0.017 and p = 0.03). Focusing on aPL-profile, regardless the diagnosis, we found a statistical significance only for aGAPSS (aPL+ =9.6 ± 6.3 vs. aPL- = 4.1 ± 5.1; p < 0.001). CONCLUSIONS: Despite QRISK3 being more accurate than traditional risk score in predicting CVD risk in SLE patients, aGAPSS appears to be the most valuable tool for this purpose.

Tailoring Tofacitinib Oral Therapy in Rheumatoid Arthritis: The TuTOR App.

To support the management of rheumatoid arthritis (RA) patients treated with tofacitinib, we designed the TuTOR (tailoring tofacitinib oral therapy in rheumatoid arthritis) mobile app. The impact of the app on medical adherence was evaluated using a crossover design alternating a paper-diary and the TuTOR App. Twenty patients with RA (mean age at inclusion, 59 ± 13 years) were included in the study. A statistically significant decrease in DAS28 was observed since the first month of therapy (mean DAS28 at baseline, 3.9 ± 1 vs. 1° month 3.1 ± 1, p = 0.0016). Similarly, the numerical rating scale (NRS) of perceived activity of disease and subjective fatigue progressively decreased. No differences were reported in DAS28 or NRS between the TuTOR app and the paper-diary groups. A significant decrease was observed in HAQ during the follow-up (baseline 1.38 ± 1.11 vs. six months 0.83 ± 0.9; p = 0.01). When filling out the self-reporting questionnaires, most of the patients (82%) preferred the TuTOR App helping them to remember to take the pills. Furthermore, 82% of patients used the app regularly (vs. 53% for the paper diary). Three patients suspended tofacitinib due to gastrointestinal intolerance. Both digital and paper devices can help maximize adherence to therapy; however, the TuTOR app was preferred by the patients for its simplicity and immediacy.

Vedolizumab for the Management of Refractory Behçet's Disease: From a Case Report to New Pieces of Mosaic in a Complex Disease.

Objectives: When treating Behçet's disease (BD), anti-tumor necrosis factor (TNF)-α agents have become a second-line therapy when conventional immunosuppressive drugs have failed. However, in the case of failure of treatment with anti-TNFα drugs, further options are limited. Based on previous reports of the efficacy of vedolizumab (VDZ) in inflammatory bowel diseases, we decided to administer VDZ to treat a patient with intestinal BD. Methods: We present the case of a 49-year-old female patient with BD. Her clinical manifestations included erythema nodosum, oro-genital ulcers, positive Pathergy test, positive HLA-B51, and biopsy-proven intestinal BD. The patient was unsuccessfully treated with conventional immunosuppressive and several biological agents. Results: Treatment with VDZ was started intravenously at a dose of 300 mg at 0, 2, and 6 weeks and then every 4 weeks. After the second dose of VDZ, the patient reported a marked improvement of intestinal BD and a concomitant amelioration of arthralgia, erythema nodosum lesions and aphthosis. Clinical remission was achieved at 6 months after starting VDZ. Conclusion: VDZ might represent a valid option to treat patients with BD who are non-responsive to standard treatments or anti-TNFα agents, particularly, those cases with intestinal involvement.

Cerebrovascular events in patients with isolated anti-phosphatidyl-serine/prothrombin antibodies.

The interest of extra-criteria antiphospholipid antibodies is growing, especially in patients negative for conventional antibodies. In this study we aimed to assess the clinical utility of anti-phosphatidyl-serine/prothrombin antibodies (aPS/PT) testing in patients negative for Beta2-Glycoprotein 1(ß2GPI)-dependent tests, for identifying antiphospholipid syndrome (APS) patients that developed cerebrovascular events (CVE). When screening APS patients attending our center, out of 119 aPS/PT IgG/IgM-positive patients, thus patients negative for aß2GPI and aCL, 42 patients (35%) tested negative for ß2GPI-dependent tests and were tested with thrombin generation assay (TGA). Ten patients (24%), with isolated aPS/PT IgG/IgM, had a history of CVE. Lupus anticoagulant (LA)-positive test was more frequently observed in patients with CVE (8/22 vs. 2/20; p = 0.045). Out of the 10 patients who experienced CVE, 3 patients were aPS/PT IgG positive (all LA positive), and 8 patients were aPS/PT IgM positive (6/8 LA positive). One patient was positive for both aPS/PT IgG and IgM. LA-positive patients had only high titers of aPS/PT IgG/IgM, all of them being ≥ 80 U/ml, while the 2 LA-negative patients were aPS/PT IgM positive with medium titers [40-60 U/ml]. LA-positive patients had significantly altered TGA profile when compared to those who were LA negative, considering all TGA parameters. LA-positive patients had significantly higher tLag (8.4 ± 3.3 min vs. 6.6 ± 1.8 min; p = 0.046), higher tPeak (14 ± 4.3 min vs. 11 ± 2.7 min; p = 0.015) and lower Peak (207 ± 152 nM vs. 356.3 ± 104.7 nM; p < 0.001) and lower AUC (2109.7 ± 1006.9 nM vs. 2772.5 ± 776.8 nM; p = 0.033). The use of aPS/PT might be of help in identifying patients with CVE and APS, as also confirmed by TGA testing.

Genetic Factors in Antiphospholipid Syndrome: Preliminary Experience with Whole Exome Sequencing.

As in many autoimmune diseases, the pathogenesis of the antiphospholipid syndrome (APS) is the result of a complex interplay between predisposing genes and triggering environmental factors, leading to a loss of self-tolerance and immune-mediated tissue damage. While the first genetic studies in APS focused primarily on the human leukocytes antigen system (HLA) region, more recent data highlighted the role of other genes in APS susceptibility, including those involved in the immune response and in the hemostatic process. In order to join this intriguing debate, we analyzed the single-nucleotide polymorphisms (SNPs) derived from the whole exome sequencing (WES) of two siblings affected by APS and compared our findings with the available literature. We identified genes encoding proteins involved in the hemostatic process, the immune response, and the phospholipid metabolism (PLA2G6, HSPG2, BCL3, ZFAT, ATP2B2, CRTC3, and ADCY3) of potential interest when debating the pathogenesis of the syndrome. The study of the selected SNPs in a larger cohort of APS patients and the integration of WES results with the network-based approaches will help decipher the genetic risk factors involved in the diverse clinical features of APS.

Improving diagnosis for rare diseases: the experience of the Italian undiagnosed Rare diseases network.

BACKGROUND: For a number of persons with rare diseases (RDs) a definite diagnosis remains undiscovered with relevant physical, psychological and social consequences. Undiagnosed RDs (URDs) require other than specialised clinical centres, outstanding molecular investigations, common protocols and dedicated actions at national and international levels; thus, many "Undiagnosed RDs programs" have been gradually developed on the grounds of a well-structured multidisciplinary approach. METHODS: The Italian Undiagnosed Rare Diseases Network (IURDN) was established in 2016 to improve the level of diagnosis of persons with URD living in Italy. Six Italian Centres of Expertise represented the network. The National Centre for Rare Diseases at the Istituto Superiore di Sanità coordinates the whole project. The software PhenoTips was used to collect the information of the clinical cases. RESULTS: One hundred and ten cases were analysed between March 2016 and June 2019. The age of onset of the diseases ranged from prenatal age to 51 years. Conditions were predominantly sporadic; almost all patients had multiple organs involvements. A total of 13/71 family cases were characterized by WES; in some families more than one individual was affected, so leading to 20/71 individuals investigated. Disease causing variants were identified in two cases and were associated to previously undescribed phenotypes. In 5 cases, new candidate genes were identified, although confirmatory tests are pending. In three families, investigations were not completed due to the scarce compliance of members and molecular investigations were temporary suspended. Finally, three cases (one familial) remain still unsolved. Twelve undiagnosed clinical cases were then selected to be shared at International level through PhenomeCentral in accordance to the UDNI statement. CONCLUSIONS: Our results showed a molecular diagnostic yield of 53,8%; this value is comparable to the diagnostic rates reported in other international studies. Cases collected were also pooled with those collected by UDNI International Network. This represents a unique example of global initiative aimed at sharing and validating knowledge and experience in this field. IURDN is a multidisciplinary and useful initiative linking National and International efforts aimed at making timely and appropriate diagnoses in RD patients who still do not have a confirmed diagnosis even after a long time.

Treatment of antiphospholipid syndrome.

Antiphospholipid syndrome (APS) is the most common acquired thrombophilia. The clinical manifestations of APS are mainly vascular thrombosis (venous and/or arterial) and/or recurrent pregnancy morbidity with the concomitant persistent presence of antiphospholipid antibodies (aPL). Therefore, the goals of the treatment of patients with APS are reducing the pregnancy morbidity and/or the prevention of thrombotic events during the follow-up. Optimal treatment of APS has long been discussed, due to the heterogeneity of the clinical manifestations and the consequent plurality in the medical specialties involved in managing this condition. This review summarizes the available evidence on primary thromboprophylaxis in aPL-positive individuals with no prior thrombotic events, secondary prophylaxis in patients with positive history for thrombotic events, the management of refractory or difficult cases and the current strategies for the management of APS during pregnancy.