Activated phosphoinositde 3-kinase (PI3Kδ) syndrome: an Italian point of view on diagnosis and new advances in treatment.

Activated phosphoinositide 3-kinase (PI3Kδ) Syndrome (APDS) is an inborn error of immunity (IEI) with a variable clinical presentation, characterized by infection susceptibility and immune dysregulation that may overlaps with other Primary Immune Regulatory Disorders (PIRDs). The rarity of the disease, its recent discovery, and the multiform /multifaced clinical presentation make it difficult to establish a correct diagnosis, especially at an early stage. As a result, the true prevalence of the pathology remains unknown. There is no treatment protocol for APDS, and drug therapy is primarily focused on treating symptoms. The most common therapies include immunoglobulin replacement therapy, antimicrobial prophylaxis, and immunosuppressive drugs. Hematopoietic stem cell transplantation (HSCT) has been used in some cases, but the risk-benefit balance remains unclear. With the upcoming introduction of specific medications, such as selective inhibitors for PI3Kδ, clinicians are shifting their attention towards target therapy.This review provides a comprehensive overview of APDS with a focus on diagnostic and treatments procedures available. This review may be useful in implementing strategies for a more efficient patients' management and therapeutic interventions.Main Text.

Long-term and real-world safety and efficacy of retroviral gene therapy for adenosine deaminase deficiency.

Adenosine deaminase (ADA) deficiency leads to severe combined immunodeficiency (SCID). Previous clinical trials showed that autologous CD34+ cell gene therapy (GT) following busulfan reduced-intensity conditioning is a promising therapeutic approach for ADA-SCID, but long-term data are warranted. Here we report an analysis on long-term safety and efficacy data of 43 patients with ADA-SCID who received retroviral ex vivo bone marrow-derived hematopoietic stem cell GT. Twenty-two individuals (median follow-up 15.4 years) were treated in the context of clinical development or named patient program. Nineteen patients were treated post-marketing authorization (median follow-up 3.2 years), and two additional patients received mobilized peripheral blood CD34+ cell GT. At data cutoff, all 43 patients were alive, with a median follow-up of 5.0 years (interquartile range 2.4-15.4) and 2 years intervention-free survival (no need for long-term enzyme replacement therapy or allogeneic hematopoietic stem cell transplantation) of 88% (95% confidence interval 78.7-98.4%). Most adverse events/reactions were related to disease background, busulfan conditioning or immune reconstitution; the safety profile of the real world experience was in line with premarketing cohort. One patient from the named patient program developed a T cell leukemia related to treatment 4.7 years after GT and is currently in remission. Long-term persistence of multilineage gene-corrected cells, metabolic detoxification, immune reconstitution and decreased infection rates were observed. Estimated mixed-effects models showed that higher dose of CD34+ cells infused and younger age at GT affected positively the plateau of CD3+ transduced cells, lymphocytes and CD4+ CD45RA+ naive T cells, whereas the cell dose positively influenced the final plateau of CD15+ transduced cells. These long-term data suggest that the risk-benefit of GT in ADA remains favorable and warrant for continuing long-term safety monitoring. Clinical trial registration: NCT00598481 , NCT03478670 .

Rheumatological complaints in H syndrome: from inflammatory profiling to target treatment in a case study.

BACKGROUND: H Syndrome is a rare genetic condition caused by biallelic pathogenic variants in the SLC29A3 gene. It is characterized by a wide range of clinical manifestations, many of which are related to the immune-rheumatological field. These include scleroderma-like skin changes, deforming arthritis, and enlarged lymph nodes. The condition also features cardiac and endocrine defects, as well as hearing loss, for which the immune pathogenesis appears less clear. Immunomodulatory medications have been shown to improve many symptoms in recent experiences. CASE PRESENTATION: A 21-year-old girl was referred to our institute after being diagnosed with H syndrome. Her medical history was characterized by the development of finger and toe deformities, which developed since the first years of life and progressively worsened with clinodactyly. At 6 years of age, she was diagnosed with diabetes mellitus without typical autoantibodies and with bilateral sensorineural hearing loss. She also complained of frequent episodes of lymphadenopathy, sometimes with colliquation and growth retardation due to pancreatic insufficiency. It wasn't until the genetic diagnosis of H syndrome that the continual increase in acute phase reactants was noticed, suggesting that an immunological pathogenesis may be the source of her problems. During her visit to our institute, she reported serious pain in both feet and hands and difficulty walking due to knee arthritis and muscle contractures. Conventional therapy with steroid injection in affected joints and methotrexate only led to partial improvement. After a thorough assessment of her inflammatory profile showing a high interferon score, the girl received treatment with baricitinib. Furthermore, based on recent data showing that SLC29A3 deficiency results in interferon production because of Toll-like Receptor 7 activation in lysosomes, hydroxychloroquine was also added. The combination of the two drugs resulted for the first time in a rapid and persistent normalization of inflammatory markers, paralleled by a dramatic improvement in symptoms. CONCLUSIONS: We describe the results of inhibiting IFN inflammation in H syndrome and discuss how JAK inhibitors and antimalarials might represent a mechanistically based treatment for this orphan drug disorder.

Erythropoietic protoporphyria: case reports for clinical and therapeutic hints.

BACKGROUND: Erythropoietic protoporphyria is a rare disorder which represents an important health problem in children, causing painful photosensitivity. Little is known on the correlation between genetic profile and clinical manifestations. The standard of care for Erythropoietic protoporphyria is based on avoiding sun and using sun protections, but recent literature has suggested that cimetidine may have a role in improving sun sensitivity. Herein we report our case series describing the successful use of cimetidine and analyzing potential phenotype-genotype correlations. CASE PRESENTATION: This case series describes five patients presented to our Rheumatology Service complaining sun sensitivity. Blood exams and genetic analysis were consistent with the diagnosis of erythropoietic protoporphyria. Four of 5 patients received cimetidine in addition to standard therapies and the effect of treatment was evaluated by Erythropoietic Protoporphyria - Quality of Life questionnaire. CONCLUSIONS: Erythropoietic protoporphyria usually manifests in early childhood after a short sun exposure. Skin manifestations are the main reason for investigations, although sometimes they can be more subtle, leading to a significant diagnostic delay. Skin diseases in children can have profound effects on their family and social relationships. A treatment with cimetidine appears to be an excellent therapeutic option in children with Erythropoietic protoporphyria.

A very rare cause of pre-capillary pulmonary hypertension: The PAMI syndrome.

We report the first known case of PAMI syndrome associated with pulmonary arterial hypertension (PAH) with a positive response to cyclophosphamide and pulmonary vasodilators. The patient's history began at 7 months with severe pancytopenia and fever. As time progressed, migrating arthritis, hepatosplenomegaly, and a growth deficit manifested without a plausible explanation. At the age of 17, worsening dyspnea led to a diagnosis of severe pre-capillary pulmonary hypertension and, after a multidisciplinary evaluation, a dual therapy with both vasoactive and immunosuppressive agents led to rapid clinical improvement. After a decade of stability, stopping sildenafil caused deterioration, reversed upon reintroduction. Thirty years after the onset of signs and symptoms, a genetic test identified the underlying condition known as PAMI syndrome. As PAMI syndrome involves intense systemic inflammation similar to PAH related to systemic lupus erythematosus (SLE), parameters and functional autonomy appropriately responded to early immunosuppressive and vasoactive therapy. PAMI syndrome, a rare autoinflammatory disease, is linked to precapillary pulmonary hypertension but the exact cause and optimal treatment approach are not fully understood, requiring further research for clarification and improved treatment options.

Subcutaneous tocilizumab in the management of non-infectious uveitis in children: a brief report.

BACKGROUND: Tocilizumab is a humanized monoclonal antibody that acts as an IL-6 receptor antagonist. Intravenous tocilizumab is considered an option for children with anti-TNF refractory juvenile idiopathic arthritis-associated uveitis. In contrast, the potential of subcutaneous drug use with this indication is more controversial. Due to the decreased availability of intravenous tocilizumab during the COVID-19 pandemic, we started using the subcutaneous formulation of the drug in children with anti-TNF refractory uveitis. The study analyzes the serum concentration of tocilizumab and its clinical response in patients with anti-TNF refractory uveitis who started or switched to subcutaneous administration from intravenous use. METHODS: Five patients with non-infectious uveitis were treated with subcutaneous tocilizumab. Ocular inflammation was evaluated on slit lamp examination during clinical control. Serum tocilizumab concentrations were determined by ELISA. RESULTS: The mean blood concentration of tocilizumab was 61.4 µg/mL (range 2.7-137.0.), with higher values than levels recorded in adult patients with rheumatoid arthritis treated with intravenous tocilizumab. Three patients entered clinical remission. One patient developed a mild relapse and was treated with topical steroids. Only one patient did not respond to therapy. The medication was well tolerated without severe infection or other adverse events. CONCLUSION: Our results support a possible role of subcutaneous tocilizumab in anti-TNF refractory uveitis.

A "SURFin' Leukemia": Acute Lymphoblastic Leukemia Masquerading as a Syndrome of Undifferentiated Recurrent Fever.

Periodic fever is not uncommon in childhood and is often ascribed to autoinflammatory conditions; however, it may be present also in children with cancer. We here describe the case of a 3-year-old boy with acute lymphoblastic leukemia who initially presented with a 4-month history of recurrent, stereotyped episodes of fever and localized joint pain, separated by completely symptom-free intervals. These symptoms were initially interpreted as a possible syndrome of undifferentiated recurrent fever until more signs of leukemia became apparent. Our report confirms that acute lymphoblastic leukemia can rarely present with periodic fever, thus possibly leading to diagnostic errors unless a high index of suspicion is maintained.

Genetic bases of C7 deficiency: systematic review and report of a novel deletion determining functional hemizygosity.

Primary complement system (C) deficiencies are rare but notably associated with an increased risk of infections, autoimmunity, or immune disorders. Patients with terminal pathway C-deficiency have a 1,000- to 10,000-fold-higher risk of Neisseria meningitidis infections and should be therefore promptly identified to minimize the likelihood of further infections and to favor vaccination. In this paper, we performed a systematic review about clinical and genetic patterns of C7 deficiency starting from the case of a ten-year old boy infected by Neisseria meningitidis B and with clinical presentation suggestive of reduced C activity. Functional assay via Wieslab ELISA Kit confirmed a reduction in total C activity of the classical (0.6% activity), lectin (0.2% activity) and alternative (0.1% activity) pathways. Western blot analysis revealed the absence of C7 in patient serum. Sanger sequencing of genomic DNA extracted from peripheral blood of the patient allowed the identification of two pathogenetic variants in the C7 gene: the already well-characterized missense mutation G379R and a novel heterozygous deletion of three nucleotides located at the 3'UTR (c.*99_*101delTCT). This mutation resulted in an instability of the mRNA; thus, only the allele containing the missense mutation was expressed, making the proband a functional hemizygote for the expression of the mutated C7 allele.

Inborn Errors of Immunity in Children with Autoimmune and Allergic Complaints: A Single Center Experience from Diagnosis to Treatment.

Inborn errors of immunity (IEI) associated with immune dysregulation are not sufficiently addressed in shared recommendation, resulting in delayed diagnosis and high morbidity. The availability of precision medicine for some of these immune defects makes it urgent to evaluate effective strategies to diagnose and treat such defects before the occurrence of severe complications. A diagnosis of an IEI in these patients enabled the use of a more specific treatment in most cases, and these have the potential to prevent further disease progression. We studied immune dysregulation diseases in 30 patients with autoimmune or allergic phenotypes, exploiting data from clinics and immunophenotype, genetic and transcriptome investigations, and 6 of them were diagnosed with a monogenic disorder. Our results confirm that a non-negligible number of children with IEIs may present with signs and symptoms of immune dysregulation and share many features with common multifactorial immune conditions. Reaching a genetic diagnosis becomes more likely in the presence of multiple clinical manifestations, especially when in association with abnormalities of lymphocytes subsets and/or immunoglobulins levels. Moreover, 5 of 6 patients that obtained a diagnosis of monogenic disorder received precision therapy, in four cases with a good or moderate response.

Type I interferon signature as a possible new marker for stratification of patients with juvenile idiopathic arthritis.

OBJECTIVES: The interferon score (IS) quantifies the expression of interferon-stimulated genes in peripheral blood, providing an indirect estimate of interferon-mediated inflammation in rheumatological disorders. This study explores the clinical significance of IS among a cohort of patients affected by juvenile idiopathic arthritis (JIA) and its relevance to disease stratification and prognosis. METHODS: All patients referred to the Rheumatology Service of the Institute for Maternal and Child Health IRCCS Burlo Garofolo, Trieste, Italy, with a diagnosis of JIA (2001 ILAR criteria) were consecutively recruited. Systemic JIA was excluded. Demographic, clinical and laboratory data were collected for each patient in a structured database. Categorical variables were expressed as numbers (%) and compared by the χ2 test or Fisher's exact test. Principal Component Analysis (PCA) was performed with clinical and laboratory data. RESULTS: Forty-four patients were recruited (35 F, 9 M): 19 polyarticular, 13 oligoarticular, 6 oligoarticular-extended, 5 psoriatic and 1 enthesitis-related arthritis. Sixteen had a positive IS (≥3). Increased IS correlated with a higher number of involved joints ≥5 (p=0.013), increased erythrocyte sedimentation rate (ESR) (p=0.026) and hypergammaglobulinaemia (p=0.003). PCA highlighted a subgroup of patients who shared high levels of IS, ESR, C-reactive protein, hypergammaglobulinaemia, JADAS-27, polyarticular involvement and family history of autoimmunity. CONCLUSIONS: Although based on a small case series, our results may support the role of IS in better defining a subgroup of JIA subjects with stronger autoimmune features. The possible relevance of these results for therapeutic stratification remains to be explored.

A toddler with an unusually severe polyarticular arthritis and a lung involvement: a case report.

BACKGROUND: COPA syndrome is a rare hereditary inflammatory disease caused by mutations in the gene encoding the coatomer protein subunit alpha, causing excessive production of type I interferon. This case is a reminder for the general paediatrician, highlighting the relevance of the association between arthritis and lung involvement in toddlers. CASE PRESENTATION: We report the case of a 2-year-old girl with intermittent limping and joint pain. Her family history was relevant for a Still disease with lung involvement in the mother. Physical examination showed moderate wrist swelling. Laboratory findings on admission showed an increase in inflammatory markers, positive rheumatoid factor, antibodies antinuclear antibody (ANA) and cyclic citrullinated peptide (anti-CCP). Wrists' ultrasound documented synovial thickening, and chest X-rays showed an unexpected severe interstitial pneumopathy. Genetic testing confirmed the diagnosis of a heterozygous mutation of the COPA gene in c.841C > T (p.R281W). Janus kinase treatment was started (baricitinib, 4 mg daily per os) with a remarkable improvement in limping and joint pain after two weeks. CONCLUSIONS: In cases of recurrent arthritis with family history and multiple involvement organs, a genetic disorder should be suspected and genetic testing should be performed. Furthermore, this case suggests that therapy with jak inhibitors may be effective and safe in interferonopathies.

Use of the Auto-inflammatory Disease Activity Index to monitor disease activity in patients with colchicine-resistant Familial Mediterranean Fever, Mevalonate Kinase Deficiency, and TRAPS treated with canakinumab.

OBJECTIVES: To evaluate the feasibility of the autoinflammatory disease activity index (AIDAI) as a tool to assess disease activity in patients with hereditary recurrent fever syndromes (HRFs) treated with canakinumab. METHODS: Patients with active colchicine-resistant familial Mediterranean fever (crFMF), mevalonate kinase deficiency (MKD), or tumor necrosis factor receptor-associated periodic syndrome (TRAPS) were enrolled in the phase III CLUSTER study and asked to complete the AIDAI questionnaire daily. All patients included in the analysis were treated with canakinumab, but regimens and periods of treatment varied per study protocol. The AIDAI for each patient was calculated weekly over the first 40 weeks of study, based on the diaries completed over 30 days. Disease-specific cut-off AIDAI values for inactive disease were calculated in a ROC analysis by comparing AIDAI scores with the occurrence of clinically inactive disease, based on the physician global assessments of disease activity and the occurrence of flares. RESULTS: Sixty patients with crFMF, 70 with MKD, and 43 with TRAPS were included in the analysis. Median AIDAI scores were high during the first 4 weeks for the three disease cohorts, and decreased afterwards, with some differences between disease cohorts. AIDAI values of 12.0, 9.6 and 15.5 were obtained as the most optimal thresholds to discriminate patients with inactive disease, with sensitivity and specificity values mostly over 75%. CONCLUSIONS: The AIDAI allows to discriminate between patients with active and inactive HRFs, and can be used in clinical practice to monitor the disease course of patients and the effect of medications.