A Nationwide Study of GATA2 Deficiency in Italy Reveals Novel Symptoms and Genotype-phenotype Association.

GATA2 deficiency is a rare disorder encompassing a broadly variable phenotype and its clinical picture is continuously evolving. Since it was first described in 2011, up to 500 patients have been reported. Here, we describe a cohort of 31 Italian patients (26 families) with molecular diagnosis of GATA2 deficiency. Patients were recruited contacting all the Italian Association of Pediatric Hematology and Oncology (AIEOP) centers, the Hematology Department in their institution and Italian societies involved in the field of vascular anomalies, otorhinolaryngology, dermatology, infectious and respiratory diseases. Median age at the time of first manifestation, molecular diagnosis and last follow-up visit was 12.5 (age-range, 2-52 years), 18 (age-range, 7-64 years) and 22 years (age-range, 3-64), respectively. Infections (39%), hematological malignancies (23%) and undefined cytopenia (16%) were the most frequent symptoms at the onset of the disease. The majority of patients (55%) underwent hematopoietic stem cell transplantation. During the follow-up rarer manifestations emerged. The clinical penetrance was highly variable, with the coexistence of severely affected pediatric patients and asymptomatic adults in the same pedigree. Two individuals remained asymptomatic at the last follow-up visit. Our study highlights new (pilonidal cyst/sacrococcygeal fistula, cholangiocarcinoma and gastric adenocarcinoma) phenotypes and show that lymphedema may be associated with null/regulatory mutations. Countrywide studies providing long prospective follow-up are essential to unveil the exact burden of rarer manifestations and the natural history in GATA2 deficiency.

Type 1 diabetes and inborn errors of immunity: Complete strangers or 2 sides of the same coin?

Type 1 diabetes (T1D) is a polygenic disease and does not follow a mendelian pattern. Inborn errors of immunity (IEIs), on the other hand, are caused by damaging germline variants, suggesting that T1D and IEIs have nothing in common. Some IEIs, resulting from mutations in genes regulating regulatory T-cell homeostasis, are associated with elevated incidence of T1D. The genetic spectrum of IEIs is gradually being unraveled; consequently, molecular pathways underlying human monogenic autoimmunity are being identified. There is an appreciable overlap between some of these pathways and the genetic variants that determine T1D susceptibility, suggesting that after all, IEI and T1D are 2 sides of the same coin. The study of monogenic IEIs with a variable incidence of T1D has the potential to provide crucial insights into the mechanisms leading to T1D. These insights contribute to the definition of T1D endotypes and explain disease heterogeneity. In this review, we discuss the interconnected pathogenic pathways of autoimmunity, ß-cell function, and primary immunodeficiency. We also examine the role of environmental factors in disease penetrance as well as the circumstantial evidence of IEI drugs in preventing and curing T1D in individuals with IEIs, suggesting the repositioning of these drugs also for T1D therapy.

Corticosteroid-induced remission and mycophenolate maintenance therapy in granulomatous lymphocytic interstitial lung disease: long-term, longitudinal change in lung function in a single-centre cohort.

Aim: The aim of the study was to evaluate the response in lung function to different treatment regimens for common variable immunodeficiency patients with granulomatous lymphocytic interstitial lung disease (GLILD). Method: A longitudinal retrospective cohort study was carried out. Patients were divided into three groups. To assess the response to different treatments, we compared baseline lung function with post-treatment tests. Results: 14 patients with GLILD were included, seven of whom were treated with acute corticosteroids for a mean duration of 132±65 days. Spirometry results were unchanged, but there was a significant improvement in diffusing capacity of the lung for carbon monoxide (D LCO)% and transfer coefficient of the lung for carbon monoxide (K CO)% (median change in D LCO%=7%, p=0.04, and K CO%=13%, p=0.02). Relapse occurred in three out of seven patients. Five patients were treated with long-term mycophenolate mofetil (MMF) with/without corticosteroids for a mean duration of 1277±917 days. No changes were found in spirometry; however, there was a significant increase in D LCO% and K CO% (median change in each of D LCO% and K CO%=10%, p=0.04). Four patients on steroids with MMF successfully weaned the prednisone dose over 12 months. Four patients never received immunosuppression therapy. A significant decline was found in their lung function assessed over 7.5 years. The median reduction in the forced vital capacity (FVC)%, forced expiratory volume in 1 s (FEV1)% and D LCO% was 15%, 7% and 15%, equivalent to 2%, 1% and 2% per year, respectively. Conclusion: Corticosteroids improve gas transfer in GLILD, but patients often relapse. The use of MMF was associated with long-term effectiveness in GLILD and permits weaning of corticosteroids. A delay in initiating and continuing maintenance treatment could lead to disease progression.

Utility of the "2019 ACR/EULAR classification criteria" for the management of patients with IgG4-related disease.

BACKGROUND: The 2019 ACR/EULAR Classification Criteria for IgG4-related disease (IgG4-RD) represent a fundamental tool for patient enrollment in research studies and in clinical trials but their usefulness in daily clinical practice remains unknown. OBJECTIVE: To validate the 2019 ACR/EULAR Classification Criteria for IgG4-RD in a real-life setting and to anticipate their utility for orienting disease diagnosis and patient management. METHODS: Four experts were asked to classify 200 patients diagnosed with IgG4-RD according to the 2019 ACR/EULAR Classification Criteria for IgG4-RD. Agreement between experts was calculated and the Classification score of each patient was correlated with the following variables and outcomes: serum IgG4 and IgE; inflammatory markers; eosinophils; plasmablasts; IgG4-RD responder index; diabetes, osteoporosis, relapses; and use of rituximab. RESULTS: Among the 157/200 cases equally rated by at least three experts, 94 (59.9%) achieved IgG4-RD classification and 63 (40.1%) did not. Strong agreement among IgG4-RD experts was observed in classifying patients (k = 0.711, p<0.0001). Clinical presentations not included in the classification algorithm and lack of informative histology were the most common reasons for not achieving classification. In patients achieving classification, the Classification score did not correlate with variables of disease activity and was not associated with specific outcomes. CONCLUSIONS: The ACR/EULAR Classification Criteria represent a replicable instrument for classifying patients and a useful framework for orienting diagnosis but are of limited utility for assessing IgG4-RD activity, for predicting disease outcomes, and for defining personalized therapeutic approaches.

Catastrophic antiphospholipid syndrome presenting with aortic barrage: case report and review of the literature.

Catastrophic antiphospholipid syndrome (CAPS) is a life-threatening condition characterized by multiple thromboembolic events occurring in a short period of time, frequently accompanied by significant systemic inflammation. Aortic involvement is rare in antiphospholipid syndrome and it had been never described in the context of its catastrophic variant. Here, we report an unusual case of aortic occlusion as a debut manifestation of CAPS and discuss its clinical features with an up-to-date review of the literature to identify risk factors and clues for clinical practice.

Efficacy and safety of rituximab biosimilar (CT-P10) in IgG4-related disease: an observational prospective open-label cohort study.

OBJECTIVE: Rituximab is increasingly used in IgG4-related disease (IgG4-RD) but high costs limit its wide off-label administration. European and US regulatory agencies have recently approved rituximab biosimilars for the treatment of different rheumatologic and hematological conditions. No data are available, yet, on the efficacy and safety of rituximab biosimilars for the treatment of IgG4-RD. Scope of the present work is to evaluate the efficacy and safety of the rituximab biosimilar CT-P10 (RTX-B) in patients with IgG4-RD. METHODS: Patients with active IgG4-RD, naïve to rituximab or switched from the originator (RTX-O) to the biosimilar were treated with RTX-B and prospectively followed-up for 18 months. Safety and efficacy were assessed at six months. Relapse rate was assessed at 18 months. Disease activity was assessed by means of the IgG4-RD Responder Index (IgG4-RD RI). RESULTS: Thirty-eight patients were included in this study. Thirty-three patients (87%) were naïve to RTX. Five patients (13%) relapsed after RTX-O and were switched to RTX-B. After six months, 21 patients (60%) achieved disease remission. The median serum IgG4 concentration decreased from 1344 to 575 mg/L (p < 0.01), and the median IgG4-RD RI decreased from 7.5 to 0 (p < 0.01). B-cell depletion was observed in all patients. Eight patients (36%) relapsed within 18 months. Side effects related to RTX-B administration were observed in 14 patients (37%). These results are in line with our previous experience with RTX-O. CONCLUSIONS: The (TruximaTM) rituximab biosimilar CT-P10 represents a safe and effective alternative to rituximab originator for the treatment of IgG4-RD.

IgG4-Related Disease of the Oral Cavity. Case Series from a Large Single-Center Cohort of Italian Patients.

A series of destructive and tumefactive lesions of the oral cavity are increasingly recognized as part of the IgG4-related disease (IgG4-RD) spectrum. We herein examined the clinical, serological, radiological, and histological features of a series of patients referred to our clinic because of oral cavity lesions ultimately attributed to IgG4-RD. In particular, we studied 6 consecutive patients out of 200 patients referred to the immunology outpatient unit who presented with erosive and/or tumefactive lesions of the oral cavity. All patients underwent serum IgG4 measurement, nasal endoscopy, radiological studies, and histological evaluation of tissue specimens. The histological studies included immunostaining studies to assess the number of IgG4+ plasma cells/High-Power Field (HPF) for calculation of the IgG4+/IgG+ plasma cell ratio. Six patients (3% of the entire cohort) were diagnosed with IgG4-RD of the oral cavity based on histological evaluation. A major complaint at presentation was oral discomfort due to bulging mass. A mild to no increase in serum IgG4 was observed. Different patterns of organ involvement were associated with oral lesions. Five patients were treated with immunosuppressive therapy and two patients promptly responded to B-cell depletion with rituximab. Watchful waiting was decided in one patient with no major clinical symptoms. Involvement of the oral cavity is an infrequent manifestation of IgG4-RD but should be taken into consideration as a possible differential diagnosis of tumefactive or erosive lesions once neoplastic conditions are excluded. A histological examination of biopsy samples from the oral cavity represents the mainstay for diagnosis of IgG4-RD.

Clinical phenotypes of IgG4-related disease reflect different prognostic outcomes.

INTRODUCTION: Four clinical phenotypes of IgG4-related disease (IgG4-RD) have been recently identified by latent class analysis (LCA): pancreato-biliary (group 1); retroperitoneum/aortitis (group 2); head and neck limited (group 3); and Mikulicz/systemic (group 4). The reproducibility of this classification in clinical practice and its relevance for patient management, however, remain unknown. METHODS: The study included 179 patients. Four IgG4-RD experts were asked to classify a validation cohort of 40 patients according to published LCA-derived phenotypes based on clinical judgement. Agreement between LCA and clinical clustering was calculated. To assess differences among disease phenotypes, the following variables were recorded on an additional 139 patients: serum IgG4 and IgE; inflammatory markers; eosinophils; plasmablasts; IgG4-RD responder index (RI); history of atopy, diabetes, osteoporosis, relapses and malignancy; cumulative dose of glucocorticoids; and use of rituximab. RESULTS: Clinical judgement replicated LCA classification with strong agreement among IgG4-RD experts (κ = 0.841, P < 0.0005). At disease onset, group 1 showed the highest levels of serum IgG4 and IgE. Groups 2 and 4 had the lowest and highest IgG4-RD RI, respectively. At 2 years' follow-up, group 3 received the highest cumulative dose of glucocorticoids, but higher incidences of diabetes mellitus were observed in groups 1 and 4, consistent with the higher likelihood of pancreatic involvement in groups 1 and 4. No difference among the four groups was observed in terms of disease recurrence, time to relapse and frequency of rituximab infusion. CONCLUSION: Clinical phenotypes of IgG4-RD reflect differences in epidemiological features and prognostic outcomes.

Advances in the diagnosis and management of IgG4 related disease.

IgG4 related disease was recognized as a unified disease entity only 15 years ago. Awareness of IgG4 related disease has increased worldwide since then, and specialists are now familiar with most of its clinical manifestations. Involvement of the pancreato-biliary tract, retroperitoneum/aorta, head and neck, and salivary glands are the most frequently observed disease phenotypes, differing in epidemiological features, serological findings, and prognostic outcomes. In view of this multifaceted presentation, IgG4 related disease represents a great mimicker of many neoplastic, inflammatory, and infectious conditions. Histopathology remains key to diagnosis because reliable biomarkers are lacking. Recently released classification criteria will be invaluable in improving early recognition of the disease. IgG4 related disease is highly treatable and responds promptly to glucocorticoids, but it can lead to end stage organ failure and even death if unrecognized. Prolonged courses of corticosteroids are often needed to maintain remission because the disease relapses in most patients. Rapid advancement in our understanding of the pathophysiology of IgG4 related disease is leading to the identification of novel therapeutic targets and possible personalized approaches to treatment.