B-cells depletion after treatment with rituximab predicts relapse of IgG4-related disease

OBJECTIVES

B cell depletion therapy with rituximab is effective in most patients with IgG4-related disease (IgG4-RD) but requires repeated cycles to prevent disease flares. We here aimed to assess B cells after rituximab to predict relapse of IgG4-RD and guide retreatment.

METHODS

Patients with active IgG4-RD included in this retrospective study fulfilled the ACR/EULAR Classification Criteria. Total CD19+ B cells, plasmablasts, naïve and memory B cells were measured on peripheral blood by flow-cytometry at baseline and six months after rituximab. All patients were treated with two 1 g infusions of rituximab 15 days apart and monitored for 48 months. Disease response was assessed using the IgG4-RD Responder Index.

RESULTS

Thirty-three patients were included. Six months after rituximab, disease response was observed in all patients. Complete depletion of CD19+ B cells, plasmablasts, naïve and memory B cell depletion was achieved in 30%, 55%, 39%, and 42% of cases, respectively. Twenty-three relapses (70%) were observed at a median time of 24 months after rituximab. Relapse rate was significantly higher in patients who failed to achieve complete depletion of CD19+ cells (60% vs 17%, p= 0.02), naïve B cells (54% vs 15%, p= 0.01), or memory B cells (50% vs 16%, p= 0.03) six months after rituximab. The median relapse free survival time was shorter in patients who failed to achieve complete depletion of CD19+ cells (19 vs 38 months, p= 0.02), naïve B cells (16 vs 38 months, p= 0.01), or memory B cells (19 vs 38 months, p= 0.03) six months after rituximab.

CONCLUSIONS

The degree of B cell depletion six months after rituximab may predict disease flare and may instruct on the pacing of B cell depletion therapy in IgG4-RD.

Increased prevalence of malignancies in patients with IgG4-related disease: implications for clinical care

OBJECTIVES

The association between cancer and IgG4-related disease (IgG4-RD) is evolving. The primary aim of this study was to investigate the prevalence of malignancies in IgG4-RD. The secondary aim was to describe the epidemiological and clinical characteristics of IgG4-RD patients with a history of cancer.

METHODS

Two hundred and ten patients with IgG4-RD were included in this retrospective study. IgG4-RD phenotypes, clinical and serological variables were analyzed. The prevalence of cancer in IgG4-RD was compared with that in the Italian population using the registry of the Global Cancer Observatory (GCO) of the World Health Organization. The Standardized Incidence Ratio (SIR) for cancer in IgG4-RD was obtained based on the 5-years Limited Duration Prevalence (2015-2020) of tumors in the Italian population.

RESULTS

Thirty-seven/210 patients (18%) developed cancer before or after the diagnosis of IgG4-RD. Solid and hematologic tumors were more frequently observed in pancreato-biliary IgG4-RD. The SIR for malignancy in IgG4-RD patients was 2.54 higher than the general Italian population (p= 0.007). The SIR was 2.78 higher for males (p= 0.005) and 1.15 higher for females (p> 0.05). Thirty-two malignancies were diagnosed before and 16 after IgG4-RD diagnosis. Interval "from IgG4-RD to cancer" was shorter than that "from cancer to IgG4-RD". Most tumors occurring after IgG4-RD developed within 36 months from diagnosis of IgG4-RD.

CONCLUSIONS

The prevalence of cancer in patients with IgG4-RD is increased compared with the Italian population and mechanistically suggests a possible paraneoplastic association. Close surveillance is warranted for the first 36 months after IgG4-RD diagnosis.

Type 1 Autoimmune Pancreatitis in Europe: Clinical Profile and Response to Treatment

BACKGROUND & AIMS

Autoimmune pancreatitis (AIP) is an immune-mediated disease of the pancreas with distinct pathophysiology and manifestations. Our aims were to characterize type 1 AIP in a large pan-European cohort and study the effectiveness of current treatment regimens.

METHODS

We retrospectively analyzed adults diagnosed since 2005 with type 1 or not-otherwise-specified AIP in 42 European university hospitals. Type 1 AIP was uniformly diagnosed using specific diagnostic criteria. Patients with type 2 AIP and those who had undergone pancreatic surgery were excluded. The primary end point was complete remission, defined as the absence of clinical symptoms and resolution of the index radiologic pancreatic abnormalities attributed to AIP.

RESULTS

We included 735 individuals with AIP (69% male; median age, 57 years; 85% White). Steroid treatment was started in 634 patients, of whom 9 (1%) were lost to follow-up. The remaining 625 had a 79% (496/625) complete, 18% (111/625) partial, and 97% (607/625) cumulative remission rate, whereas 3% (18/625) did not achieve remission. No treatment was given in 95 patients, who had a 61% complete (58/95), 19% partial (18/95), and 80% cumulative (76/95) spontaneous remission rate. Higher (≥0.4 mg/kg/day) corticosteroid doses were no more effective than lower (<0.4 mg/kg/day) doses (odds ratio, 0.428; 95% confidence interval, 0.054-3.387) and neither was a starting dose duration >2 weeks (odds ratio, 0.908; 95% confidence interval, 0.818-1.009). Elevated IgG4 levels were independently associated with a decreased chance of complete remission (odds ratio, 0.639; 95% confidence interval, 0.427-0.955). Relapse occurred in 30% of patients. Relapses within 6 months of remission induction were independent of the steroid-tapering duration, induction treatment duration, and total cumulative dose.

CONCLUSIONS

Patients with type 1 AIP and elevated IgG4 level may need closer monitoring. For remission induction, a starting dose of 0.4 mg/kg/day for 2 weeks followed by a short taper period seems effective. This study provides no evidence to support more aggressive regimens.

Association of autoimmune pancreatitis and intraductal papillary mucinous neoplasm. A retrospective analysis from a tertiary care referral center

BACKGROUND

Autoimmune Pancreatitis (AIP) is a rare chronic inflammatory disease affecting the pancreas. Chronic pancreatic inflammation represents a risk factor for pre-neoplastic conditions such as Intraductal Papillary Mucinous Neoplasia (IPMN). Due to the rarity of AIP, the incidence, and clinical features of IPMN occurring in AIP patients remains unknown.

AIMS

In the present study we aimed to explore the relationship between AIP and IPMN and to characterize the clinical features and outcomes of IPMN occurring in the context of AIP.

METHODS

We retrospectively (2008-2020) analyzed the clinical and radiological records of a large single center cohort of patients with AIP and investigated the prevalence of IPMN. We then compared the clinical, laboratory and radiological characteristics of patients with IPMN and AIP with a cohort of patients with isolated IPMN.

RESULTS

Five hundred and nineteen patients were included in this retrospective study. Sixteen patients had concomitant IPMN and AIP(3%); 61 patients had isolated AIP (12%); 442 patients had isolated IPMN (85%). The prevalence of IPMN in patients with AIP was higher than that observed in the general population (21%vs8-10%). Worrisome Features and High-Risk Stigmata were more frequently observed in IPMN occurring together with AIP compared to isolated IPMN(p < 0.05). Based on radiological features IPMN in the context of AIP was more frequently of main-duct type compared to isolated IPMN(p < 0.05).

CONCLUSION

Our data suggest that AIP represents a chronic inflammatory condition that might favor IPMN development with high-risk features. Prolonged surveillance of these patients and longitudinal studies are required to further test the association with AIP and malignant and pre-malignant conditions.

Fibrotic phenotype of IgG4-related disease

A prompt response to glucocorticoids is a clinical hallmark of IgG4-related disease. However, manifestations characterised by prominent tissue fibrosis on histological examination can be less responsive to glucocorticoid therapy than other types of IgG4-related disease. These manifestations include retroperitoneal fibrosis, fibrosing mediastinitis, Riedel thyroiditis, orbital pseudotumor, and hypertrophic pachymeningitis, among others. To explain this discrepancy, a preliminary distinction into proliferative and fibrotic phenotypes of IgG4-related disease has been proposed on the basis of clinical presentation, pathological features, and response to immunosuppressive therapy. Implications of this classification for patient management remain an important area of investigation. In this Series paper, we aim to dissect the pathophysiology of tissue fibrosis in IgG4-related disease and discuss how clinicians should approach the management of fibrotic manifestations of IgG4-related disease based on the most recent diagnostic and therapeutic developments.

Role of systemic immunosuppression on subglottic stenosis in granulomatosis with polyangiitis: Analysis of a single-centre cohort

PURPOSE

Subglottic stenosis (SGS) is a potentially life-threatening manifestation of granulomatosis with polyangiitis (GPA). Endoscopic dilation is effective, but relapses are frequent and the benefit of systemic immunosuppression in this setting is still controversial. We aimed to investigate the role of immunosuppressive treatment on SGS relapse risk.

METHODS

This is a retrospective observational study based on review of medical charts among our cohort of patients with GPA.

RESULTS

Twenty-one patients with SGS-GPA were identified, with a prevalence of 20% among our entire GPA cohort (n = 105). Compared to patients without SGS, patients with SGS-GPA had an earlier disease onset (mean age 30.2 vs. 47.3 years, p<0.001), and lower BVAS (mean 10.5 vs 13.5; p = 0.018). Five patients didn't receive systemic immunosuppression for SGS and they all (100%) relapsed after the first procedure, while among medical treatment group relapse rate was 44% (p = 0.045). When single treatment regimens are considered, rituximab (RTX) and cyclophosphamide (CYC) yielded a protective role towards the need of subsequent dilation procedure after the first if compared with absence of medical treatment. Patients with SGS and generalized disease, who initially received either a RTX- or a CYC-based induction treatment, and higher cumulative doses of glucocorticoids, showed a delayed median time to SGS relapse (36 vs. 12 months, p = 0.024).

CONCLUSIONS

Subglottic stenosis is highly prevalent in patients with GPA and may define a milder systemic disease subset occurring more frequently in younger patients. Systemic immunosuppression provides benefit in preventing recurrence of SGS in GPA patients and regimens based on cyclophosphamide or rituximab might have a non-redundant role in this setting.

Safety of Janus Kinase Inhibitors: A Real-World Multicenter Retrospective Cohort Study

OBJECTIVE

Oral Janus kinase inhibitors (JAKis) represent an effective strategy for rheumatoid arthritis (RA) treatment. A previous study supported that tofacitinib (TOF) is associated with higher incidence of cardiovascular (CV) and neoplastic events compared to tumor necrosis factor inhibitors. Given the apparent discrepancy between these data and real-world experience, we aimed to investigate the safety and efficacy of the available JAKis in a multicenter cohort.

METHODS

We retrospectively evaluated patients with RA who ever received 1 JAKi (TOF, baricitinib [BAR], upadactinib [UPA], filgotinib [FIL]) from 4 tertiary care centers in Milan, Italy. Outcomes related to JAKi safety were recorded, particularly major CV events as well as adverse events of special interest (AESIs), which included serious infections, opportunistic infections, venous thromboembolism, herpes zoster infections, liver injury, malignancies, and deaths; retention rates were also calculated. Further analyses included patients fulfilling the risk factors suggested to influence TOF safety.

RESULTS

Six hundred eighty-five patients were included and received BAR (48%), TOF (31%), UPA (14%), or FIL (7%) as first-line innovative treatment prior to a biologic. Of a total of 1137 patient-years of observation, we recorded 1 stroke and 123 (18%) AESIs, including 3 deaths, all a result of severe infections. Among patients with a higher CV risk, we observed a higher frequency of AESIs (23%).

CONCLUSION

Our real-world data confirm that JAKis are effective and carry a low risk of AESIs, especially in patients who do not display CV risk factors at baseline. Our study could not identify differences between JAKis. Different safety profiles should be defined in larger prospective cohorts.

Association of IgG4-related disease and systemic rheumatic disorders

PURPOSE

Autoimmune disorders can occur together especially in genetically predisposed individuals. We here aimed to assess the occurrence of IgG4-related disease (IgG4-RD) in association with other systemic immune-mediated conditions.

METHODS

We retrospectively analyzed the clinical records of patients with IgG4-RD followed at the IgG4-RD Clinic of San Raffaele Hospital (Milan, Italy) for pre-existing or concomitant immune-mediated disorders. IgG4-RD was diagnosed based on histological findings and on the 2011 Comprehensive Diagnostic criteria. Associated immune-mediated disorders were diagnosed based on available classification and/or diagnostic criteria.

RESULTS

Two-hundred and thirty-four patients with a definitive diagnosis of IgG4-RD were included in this study. A pre-existing immune-mediated connective tissue disease was reported in 6/234 patients (3%): one case each of sarcoidosis, Takayasu arteritis (TA), eosinophilic granulomatosis with polyangitis (EGPA), and rheumatoid arthritis; and two cases of granulomatosis with polyangitis (GPA). Organs involved by IgG4-RD included the lungs, the pancreas, the peritoneum, lacrimal glands, meninges and orbits. Sarcoidosis, EGPA, and TA preceded the onset of IgG4-RD. GPA preceded IgG4-RD onset in one case and occurred simultaneously in the other case. Rheumatoid arthritis occurred together with IgG4-RD in one case.

CONCLUSION

Our observation suggests that "secondary" IgG4-RD can present in the context of pre-existing systemic immune-mediated disorders and complicate systemic autoimmune diseases as well as chronic granulomatous conditions. Further studies are needed to define whether this peculiar clinical scenario is associated with different genetic backgrounds, pathological bases, and long-term outcomes.

B-Cell depletion therapy in IgG4-related disease: State of the art and future perspectives

IgG4-related disease (IgG4-RD) is an increasingly recognized immune-mediated fibroinflammatory disorder that promptly responds to glucocorticoids but commonly relapses during steroid tapering or after discontinuation. In the last few years, B-cell depletion therapy with rituximab (RTX) proved to be effective in the induction of remission and maintenance treatment of IgG4-RD, providing a new powerful tool in the management of this emerging condition. In this review, we outline the pathogenetic rationale for using B-cell depleting agents in IgG4-RD, we summarize available clinical experience with RTX in this disease, and we describe future possible therapies targeting B-lymphocytes that are now in the pipeline.

Development of an algorithm for IgG4-related disease management

OBJECTIVES

IgG4-related disease (IgG4-RD) is a rare fibro-inflammatory condition affecting multiple organs lacking standardized management. In this article, we review the evidence available to provide European expert-based statements on the management of IgG4-RD which were integrated in a final algorithm.

METHODS

A panel of nine European experts in IgG4-RD from different specialties was asked to elaborate a set of consensus statements through a Delphi exercise. Three rounds of survey were taken. Consensus was reached when ≥75% of the responders agreed with a statement.

RESULTS

Thirty-one statements on induction treatment, maintenance treatment, non-pharmacological treatment, and general considerations were assessed. Patients should be treated promptly in situations when there is an immediate organ threatened, or when organ damage is anticipated. Glucocorticoids (GC) are considered the first line of treatment and should be progressively tapered. Maintenance treatment is recommended for patients with high disease activity or with risk factors for relapse. Rituximab is effective for induction and maintenance of remission, but its use can be limited by economics. Low dose GC with or without GC-sparing agents can be used for maintenance therapy. Stenting or surgery should be ancillary to pharmacological treatment. Follow up should be based on physical examination, blood works, and imaging studies. Furthermore, it should be tailored on individual patient clinical history. 18-fluorodeoxyglucose positron emission tomography/computerized tomography may provide additional information over other imaging modalities.

CONCLUSIONS

These new statements and algorithm reached a high degree of agreement and may help guiding the clinical management of IgG4-RD.

AB1294 CO-OCCURRENCE OF IgG4 RELATED DISEASE AND OTHER SYSTEMIC IMMUNO-MEDIATED DISORDERS

Background

IgG4-related disease (IgG4RD) is a fibroinflammatory disease with unique clinical and pathophysiological features. According to the recently released Classification Criteria, the presence of other concomitant immunological disorders (OID) represents an exclusion criterion for the classification of IgG4RD (1). Rigorous application of the Classification Criteria, however, can lead to misdiagnosis because our increasing appraisal of IgG4RD indicates that this condition may coexists with OID (2).

Objectives

To describe IgG4RD presentation in the context of OID.

Methods

IgG4RD was diagnosed based on definitive histological findings. OID were diagnosed based on specific classification/diagnostic criteria.

Results

In six out of 234 (3%) patients IgG4RD occurred in accompaniment with OID, including two patients with sarcoidosis (33%), two with granulomatosis with polyangiitis (33%) one with eosinophilic granulomatosis with polyangiitis (16%) and one with Takayasu arteritis (16%). In three cases IgG4RD preceded OID (Table 1).

Table 1.

*ACR / EULAR 2017 provisional classification criteria for GPA **ACR 1990 Classification criteria for EGPA ***Modified diagnostic criteria for Takayasu arteritis. Shanna et al. 1995. Abbreviations: AZA: Azathioprine; CYC: Cyclophosphamide; EGPA: Eosinophilic Granulomatosis with Polyangiitis; ENG: electroneurography; GPA: Granulomatosis with Polyangiitis; IgG4RD: IgG4 Related Disease; INFX: Infliximab; F: female; M: male; MPDN: Methylprednisolone; MTX: Methotrexate; N: No; PDN: Prednisone; RTX: Rituximab; TCZ: Tocilizumab; Y: Yes

GENDER (Age at IgG4RD diagnosis^)M (56)M (69)F (47)F (51)M (65)F (16)IgG4RDOrgans involvedpancreas, biliary tract, lymphnodes, nasal cavities, skin, ascending aortasalivary glands, pancreas, biliary tract, lungeyelidperiorbital region, lacrimal glandmeninges, abdominal aortaperitoneumACR/EULAR score343620212426Definite histological diagnosisYYYYYY (peritoneal lesion?)(pancreas, lymphnodes)(salivar glands, lung)(eyelid)(periorbiatl tissue, lacrimal gland)(meninges)Induction of remission therapyPDN + AZAPDNAZAPDNPDN + MTXPDN + MTXResponseYYYYYYRelapse (years after treatment)Y (6)Y (10)NY (0,5)Y (5)NSecond line therapyRTXRTX-MPDN + RTXPDN-OTHER IMMUNOLOGICAL DISEASEDiagnosisSarcoidosisSarcoidosisGPAGPAEGPATakayasuOrgans involvedlymphnodes over and infra diaphragmatic, axillary, laterocervical, lumboaortic, inguinal, hepaticpulmonary and over and infradiafragmatic lymphnodestracheal cartilagepulmonary nodules, scleritisrespiratory tract (asthma), skin, peripheral nervous system, blood eosinophilialeft subclavian artery, left common carotid, anonymous artery, thoracic aorta, suprarenal abdominal aorta, right pulmonary arteryClassification criteria fulfilled?not availablenot availableY*Y*Y**Y***Autoantibodynonenonec-ANCAc-ANCAp-ANCAnoneDefinite histological diagnosisY (lymphnode)Y (paratracheal lymphnodes)not availableY (pulmonary nodule)Y (skin biopsy)not availableTiming of diagnosis vs IgG4RDsubsequentpreviouspreviouscontemporarypreviouscontemporaryYears after/before IgG4RD diagnosis2112030TreatmentPDNPDN + MTXPDN + AZAPDNPDN + CYCINFXResponse to treatmentYYYYYN

Conclusion

Our data demonstrate that IgG4RD can occur in overlap with OID, especially granulomatous diseases. Further research is needed to define whether this clinical scenario is associated with different pathological bases and long-term outcomes.

References

[1]Wallace ZS et al., Ann Rheum Dis, 2020

[2]Mizushima I et al., Rheumatology, 2021

Disclosure of Interests

None declared

AB1278 INCIDENCE OF ENDOCRINE AND EXOCRINE INSUFFICIENCY IN PATIENTS WITH AUTOIMMUNE PANCREATITIS AT DIAGNOSIS AND AFTER TREATMENT

Background

Autoimmune pancreatitis (AIP) is a rare form of chronic pancreatitis that may lead to endocrine and exocrine insufficiency if left untreated. AIP clinically responds to glucocorticoids (GCs) therapy, but multiple GCs courses are often required to maintain remission with potential detrimental effects on glycaemic control. To date, data on pancreatic function in AIP are scanty and heterogeneous.

Objectives

We aimed to assess the rate of endocrine and of exocrine insufficiency at diagnosis and at follow up in patients with AIP as well as the impact of GC therapy on pancreatic function in the long term.

Methods

The MEDLINE, SCOPUS, and EMBASE databases were searched from inception to August 2021 to identify studies reporting data on endocrine and exocrine insufficiency in patients with type 1or type 2 AIP. Studies involving ≥ 3 patients were selected. In case of duplicated studies, the most recent or the one with the largest sample were included. The study was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Pooled events were calculated using a random-effect model and expressed in terms of pooled prevalence rates.

Results

A total of 6522 AIP patients and sixty-two studies were included in the analysis. The pooled estimate rate for the overall prevalence of diabetes in AIP at baseline (combined type 1 and type 2 AIP) was 36.9% (95% CI 31.9-41.9, I2 96.1%). The pooled estimate for the prevalence of diabetes was 44.3% (95%CI 39.1-49.4, I2 91.9%) in type 1 AIP and 11.3% (95%CI 6.1-16.6, I2 42.5%) in type 2 AIP (p < 0.01), respectively. The pooled prevalence rate of exocrine insufficiency was 45.2% (95%CI 32.9-57.4; I2 97.4%). The pooled estimate rate of diabetes at follow-up was 44.2% (95%CI 26.1-62.4) in studies where GCs were given to 100% of patients and 41.8% (95%CI 30.6-52.9) in studies where GCs were given to less than 100% of patients. The pooled prevalence of pancreatic exocrine insufficiency was 36.2% (95%CI 20.4-52.0, I2 96.4%).

Conclusion

A large proportion of patients with AIP displays concomitant exocrine and endocrine insufficiency at the time of diagnosis. The incidence of diabetes at the longest available follow up tends to increase in patients treated with GCs. Further long-term studies are warranted to assess the impact of GCs and immunosuppressive treatments on glycaemic control and on exocrine pancreatic function.

References

[1]Löhr JM, Beuers U, Vujasinovic M, et al. European Guideline on IgG4-related digestive disease - UEG and SGF evidence-based recommendations. United European Gastroenterol J. 2020;8:637-666.

[2]Lanzillotta M, Vinge-Holmquist O, Overbeek KA, et al.PrescrAIP: A Pan-European Study on Current Treatment Regimens of Auto-Immune Pancreatitis. Front Med. 2020 Aug 5;7:408.

Disclosure of Interests

None declared

Incidence of endocrine and exocrine insufficiency in patients with autoimmune pancreatitis at diagnosis and after treatment: a systematic review and meta-analysis

BACKGROUND

Autoimmune pancreatitis (AIP) is a rare form of pancreatitis that may lead to endocrine and exocrine insufficiency if left untreated. AIP clinically responds to glucocorticoids (GCs) therapy, but multiple GCs courses are often required to maintain remission with detrimental effects on glycaemic control.

OBJECTIVE

In this systematic review and meta-analysis, we aimed to assess the rate of endocrine and of exocrine insufficiency at diagnosis and at follow up in patients with AIP as well as the impact of GC therapy on pancreatic function in the long-term.

METHODS

The MEDLINE, SCOPUS, and EMBASE databases were searched from inception to August 2021 to identify studies reporting data on endocrine and exocrine insufficiency in patients with AIP. Pooled events were calculated using a random-effect model and expressed in terms of pooled prevalence rates.

RESULTS

A total of 6522 AIP patients and sixty-two studies were included in the analysis. The pooled estimate rate for the overall prevalence of diabetes in AIP at baseline was 37% (95% CI 32-42, I² 96%). The pooled prevalence rate of exocrine insufficiency was 45% (95%CI 32.9-57.4; I² 97%). The pooled estimate rate of diabetes at follow-up was 44% (95%CI 26.1-62.4) in studies where GCs were given to 100% of patients and 42% (95%CI 30.6-52.9) in studies where GCs were given to less than 100% of patients.

CONCLUSION

A large proportion of patients with AIP displays concomitant exocrine and endocrine insufficiency at the time of diagnosis. The incidence of diabetes at the longest available follow up tends to increase in patients treated with GCs.

HLA-DRB1∗16 and -DQB1∗05 alleles are strongly associated with autoimmune pancreatitis in a cohort of hundred patients

BACKGROUND/OBJECTIVES

Autoimmune diseases are often associated with human leukocyte antigen (HLA) haplotypes, indicating that changes in major histocompatibility complex (MHC)-dependent self-peptide or antigen presentation contribute to autoimmunity. In our study, we aimed to investigate HLA alleles in a large European cohort of autoimmune pancreatitis (AIP) patients.

METHODS

Hundred patients with AIP, diagnosed and classified according to the International Consensus Diagnostic Criteria (ICDC), were prospectively enrolled in the study. Forty-four patients with chronic pancreatitis (CP) and 254 healthy subjects served as control groups. DNA was isolated from blood samples and two-digit HLA typing was performed with sequence-specific primer (SSP-) PCR. HLA allele association strength to AIP was calculated as odds ratio.

RESULTS

We uncovered a strong enrichment of HLA-DQB1 homozygosity in type 1 and type 2 AIP patients. Moreover, a significantly increased incidence of the HLA-DRB1∗16 and HLA-DQB1∗05 alleles and a concomitant lack of the HLA-DRB1∗13 allele was detected in AIP type 1 and type 2 patients. In contrast, the HLA-DQB1∗02 allele was underrepresented in the 'not otherwise specified' (NOS) AIP subtype. We detected no significant difference in the HLA-DRB3, HLA-DRB4 and HLA-DRB5 allele frequency in our cohort.

CONCLUSIONS

Although AIP type 1 and type 2 are characterized by distinct histopathological characteristics, both subtypes are associated with the same HLA alleles, indicating that the disease might rely on similar immunogenic mechanisms. However, AIP NOS represented another subclass of AIP.

Differential EUS findings in focal type 1 autoimmune pancreatitis and pancreatic cancer: A proof-of-concept study

Background and Objectives:

Autoimmune pancreatitis (AIP) often mimics pancreatic cancer (PC), particularly if presenting as a focal lesion. EUS may orient the differential diagnosis between them. This study aims to identify EUS findings that might be useful to differentiate type 1 focal autoimmune pancreatitis (f-AIP1) and PC.

Materials and Methods:

F-AIP1 and PC patients were retrospectively collected, matched, and compared. EUS findings considered were: focal mass echogenicity, loss of lobularity, distal atrophy, peripancreatic hypoechoic margins (PHM), pancreatic duct dilation, duct-penetrating sign (DPS), pancreatic/common bile duct thickened walls (PD/CBD-TW), and vessel infiltration (VI). Elastography findings were also recorded. Variables with a P < 0.05 at univariate analysis were included in logistic multiple regression.

Results:

Fifteen patients with f-AIP and 60 with PC were studied. FE was hypoechoic in all patients from both groups. PHM was observed in 40% of f-AIP1 cases but not in PC ones (P < 0.001). DPS was found in 10/15 (66.7%) f-AIP1 and in 7/60 (11.7%) PC patients (P < 0.001). PD-TW and CBD-TW were observed in 66.7%/60% f-AIP1 cases and in 6.7%/13.6% PC patients, respectively (P < 0.001 for both comparisons). Pancreatic masses were significantly different at EUS elastography (elastic respectively in 71.4% f-AIP1 and 3.8% PC, P < 0.001). VI was suspected in 20% of f-AIPs and 85% of PCs (P < 0.001). At multiple regression, PD-TW, CBD-TW, elastic pattern, and the absence of VI independently supported a diagnosis of f-AIP1.

Conclusions:

Our results suggest that EUS findings deserve consideration in the diagnostic workup of AIP to improve the differential diagnosis with PC.

Efficacy and safety of rituximab for IgG4-related pancreato-biliary disease: A systematic review and meta-analysis

BACKGROUND

Type I autoimmune pancreatitis (AIP) and IgG4-related sclerosing cholangitis (IgG4-SC) belong to the IgG4-related disease (IgG4-RD) spectrum. Both entities respond to glucocorticoids, but iatrogenic toxicity associated with prolonged steroid therapy and relapse represent relevant clinical concerns in the long-term. Rituximab is increasingly used as an effective alternative strategy to induce remission but data regarding the safety and efficacy of B-cell depletion therapy for pancreato-biliary involvement of IgG4-RD are limited. We performed a systematic review and meta-analysis to estimate the rate of remission, flare, and adverse events (AEs) occurring in pancreato-biliary IgG4-RD following rituximab treatment.

METHODS

The MEDLINE, SCOPUS, and EMBASE databases were searched from inception to December 2020 to identify studies reporting the outcomes of IgG4-related pancreato-biliary disease after treatment with rituximab. Studies involving ≥2 patients were selected. In case of duplicated studies, the most recent or the one with the biggest N were chosen. The study was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Pooled effects were calculated using a random-effect model and expressed in terms of pooled remission, relapse, and AEs rates.

RESULTS

Seven cohort studies met inclusion criteria and 101 patients were included. Reasons for rituximab administration were new disease onset (18.5%), disease flare after glucocorticoids (63.5%), and glucocorticoids intolerance (17.9%). The median follow-up time was 19 months. The pooled rate of complete response at 6 months was 88.9% (95%CI 80.5-93.9) with no heterogeneity (I² = 0%). The pooled estimate of relapse rate was 21% (95%CI 10.5-40.3) with moderate heterogeneity (I² = 51%). A higher rate of relapse (35.9%, 95%CI 17.3-60.1) was reported in studies including patients with multiorgan involvement (OOI). The median time to relapse was 10 months. The pooled estimate of rituximab-related AEs was 25% (95%CI 8.8-53) with substantial heterogeneity (I² = 73.6%). No publication bias was observed.

CONCLUSION

Treatment of IgG4-related pancreato-biliary disease with rituximab is associated with high remission rate, a higher relapse rate in the presence of OOI, and limited AEs. Randomized controlled trials with adequate power are needed to confirm these findings.

POS1247 CLINICAL FEATURES AND OUTCOMES OF COVID-19 IN PATIENTS WITH IGG4-RELATED DISEASE. A COLLABORATIVE EUROPEAN MULTI-CENTRE STUDY

Background:

Coronavirus disease 2019 (COVID-19) is a pandemic-spread systemic infectious disease with prominent respiratory manifestations and significant associated morbidity and mortality. Elderly people are most significantly affected with mortality ranging from 2.4% (age 60-69) to 19.6% (age>80) in European Countries. The prevalence of COVID-19 and of its complications in patients with immune-mediated disorders, remains unclear. The frequency and impact of COVID-19 on patients with IgG4-related diease (IgG4-RD), many of whom are on concurrent immunosuppression has not been addressed.

Objectives:

To assess the epidemiological and clinical relevance of COVID-19 in patients with IgG4-RD.

Methods:

This is a multi-centre retrospective observational study of IgG4-RD patients from France, Italy, Spain and the United Kingdom. Demographics, comorbidities, IgG4-RD features, current and past treatment along with COVID-19-suggestive symptoms and COVID-19 diagnoses from February 2020 to January 2021 were recorded by means of direct or phone interviews. Patients with reverse-transcriptase polymerase chain reaction-confirmed (cCOVID) or presumed COVID-19 based on clinical, serological or imaging features (pCOVID) were pooled for analysis (totCOVID) and compared to patients who were not diagnosed with COVID-19. Inter-group comparison of categorical and quantitative variables were performed by using the chi-square test with Fisher’s correction and the Mann-Whitney’s test respectively. Data are expressed as median (interquartile range) unless otherwise specified.

Results:

A total of 305 patients [71% males, median age 64 (54-74) years] were studied. Pancreato-biliary disease was the most frequently observed IgG4-RD phenotype (39%). Fifty-one percent of patients were taking corticosteroids at time of interview and 30% were on biological or conventional immunosuppressants. Thirty-two totCOVID cases (23 cCOVID, nine pCOVID) were identified: 11/32 were hospitalised, two needed intensive care and four (13%; 3/4 aged >80 years) died. Having one or more infected family members was a risk factor for COVID-19 in patients with IgG4-RD (OR=19.9; p<0.001). No other demographic, clinical or treatment features associated with COVID-19. In particular there was no association between adverse outcomes with COVID-19 and higher doses of steroids (>20mg) or rituximab administration.

Conclusion:

The prevalence and course of COVID-19 in IgG4-RD patients are similar to those of the general population of the same age, with no evident impact of disease- or treatment-related factors to the basal infectious risk. Effective public health countermeasures might be beneficial for patients with IgG4RD.

References:

[1]European Centre for Disease Prevention and Control (ECDC): https://covid19-surveillance-report.ecdc.europa.eu/

[2]Yang H, Ann Rheum Dis, 2021

Disclosure of Interests:

Giuseppe Alvise Ramirez: None declared, Marco Lanzillotta: None declared, Mikael Ebbo: None declared, Andreu Fernandez-Codina Consultant of: consulting fees from Atheneum Consulting, Gaia Mancuso: None declared, Fernando Martínez-Valle: None declared, Olimpia Orozco-Galvez: None declared, Nicolas Schleinitz: None declared, Lorenzo Dagna Consultant of: Abbvie, Amgen, Biogen, BristolMyers Squibb, Celltrion, Galapagos, GlaxoSmithKline, Novartis, Pfizer, Roche, Sanofi-Genzyme, and SOBI, Grant/research support from: The Unit of Immunology, Rheumatology, Allergy and Rare Diseases (UnIRAR) received unresctricted research/educational grants from Abbvie, Bristol-Myers Squibb, Celgene, GlaxoSmithKline,Janssen, Merk Sharp & Dohme, Mundipharma Pharmaceuticals, Novartis, Pfizer, Roche, Sanofi Genzyme, and SOBI, Emma L. Culver: None declared, Emanuel Della Torre: None declared

POS1356 PERSISTENCE OF TFH CELLS AFTER RITUXIMAB IS ASSOCIATED WITH IGG4-RELATED DISEASE RELAPSE

Background:

Clinical improvement after B-cell depletion with rituxmab suggests a prominent pathogenic role of B-lymphcytes in IgG4-related disease (IgG4-RD). IgG4-RD, however, relapses in most cases together with re-expansion of clonally divergent plasmablasts indicating that treatment with rituximab does not completely abrogates T follicular helper (Tfh)-cells dependent germinal center reactions leading to de-novo plasmablast differentiation.

Objectives:

In the present work we aim to study the effects of B-cell depletion therapy with rituximab on circulating Tfh cells and on the levels of CXCL13 - a chemotactic factor for B-lymphocytes produced by Tfh cells - in patients with IgG4-RD.

Methods:

Thirty patients with IgG4-RD, diagnosed according to the “Consensus Statement on the Pathology of IgG4-RD” and fulfilling the “2019 ACR/EULAR Classification Criteria” were included in the present study. Ten patients with relapsing disease were treated with the anti-CD20 monoclonal antibody rituximab (two 1g infuxions 15 days apart). Peripheral blood mononuclear cells and serum were collected before rituximab and three months after infusion. Tfh cells subsets in the peripheral blood were measured by flow cytometry and CXCL13 plasma levels were measured by ELISA assay.

Results:

No changes in total Tfh cells and Tfh cells subsets were observed three months after rituximab neither in absolute counts nor in percentage of CD4+ T cells. In particular, no difference in Tfh1, Tfh2, Tfh17, T follicular regulatory and highly functional Tfh cells counts was observed before and after treatment. The serum level of CXCL13 was significantly higher in active untreated IgG4-RD patients compared to healthy controls (151.94 pg/ml vs 66.98 pg/ml, p value = 0.0026), but was not affected by rituximab treatment (p value = 0.41).

Conclusion:

In relapsing patients with IgG4-RD rituximab does not affect circulating Tfh cells numbers and serum levels of CXCL13. Persistence of Tfh cells after rituximab and reconstitution of germinal center reactions likely drives IgG4-RD flare.

References:

[1]Lanzillotta M, Mancuso G, Della-Torre E. Advances in the diagnosis and management of IgG4 related disease. BMJ. 2020 Jun 16;369:m1067. doi: 10.1136/bmj.m1067. PMID: 32546500.

[2]Lanzillotta M, Della-Torre E, Stone JH. Roles of Plasmablasts and B Cells in IgG4-Related Disease: Implications for Therapy and Early Treatment Outcomes. Curr Top Microbiol Immunol. 2017;401:85-92. doi: 10.1007/82_2016_58. PMID: 28091934.

[3]Campochiaro C, Ramirez GA, Bozzolo EP, Lanzillotta M, Berti A, Baldissera E, Dagna L, Praderio L, Scotti R, Tresoldi M, Roveri L, Mariani A, Balzano G, Castoldi R, Doglioni C, Sabbadini MG, Della-Torre E. IgG4-related disease in Italy: clinical features and outcomes of a large cohort of patients. Scand J Rheumatol. 2016;45(2):135-45. doi: 10.3109/03009742.2015.1055796. Epub 2015 Sep 23. PMID: 26398142.

[4]Mattoo H, Mahajan VS, Della-Torre E, Sekigami Y, Carruthers M, Wallace ZS, Deshpande V, Stone JH, Pillai S. De novo oligoclonal expansions of circulating plasmablasts in active and relapsing IgG4-related disease. J Allergy Clin Immunol. 2014 Sep;134(3):679-87. doi: 10.1016/j.jaci.2014.03.034. Epub 2014 May 6. PMID: 24815737; PMCID: PMC4149918.

Disclosure of Interests:

None declared

POS1382 RITUXIMAB FOR INDUCTION OF REMISSION IN TYPE 1 AUTOIMMUNE PANCREATITIS: A SYSTEMATIC REVIEW AND META-ANALYSIS

Background:

Type I autoimmune pancreatitis (AIP) is a rare form of pancreatitis that belongs to the IgG4-related disease (IgG4-RD) spectrum (1). Autoimmune pancreatitis responds brilliantly to glucocorticoids, but iatrogenic toxicity associated with prolonged steroid therapy represents a relevant clinical concern in the long-term (2). B cell depletion therapy proved to be effective in inducing IgG4-RD remission, yet most evidence are derived from small and heterogenous cohorts.

Objectives:

We performed a systematic review and meta-analysis to estimate the remission rate following rituximab-based induction treatment.

Methods:

Two reviewers searched MEDLINE, SCOPUS, and EMBASE until December 2020 to identify studies on remission rate and relapse rate of Type I AIP after induction of remission with rituximab. Studies involving three or more patients were included, including the most recent or most numerous cohorts in case of duplicates This study was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Pooled effects were calculated using a random-effects model and expressed in terms of pooled remission, relapse and adverse effects (AEs) rates.

Results:

Seven cohort studies met inclusion criteria for the meta-analysis for a total of 101 patients. Reasons for rituximab administration were relapsing disease (63.5%), new diagnosis (18.5%) or glucorticoids intolerance (17.9%). The median follow-up time was 18.5 months. The pooled rate of complete response at 6 months from induction of remission was 88.9% (95% CI 80.5%-93.9%) without heterogeneity (I2=0%) (Figure 1). The median time to relapse was 9.75 months. The pooled estimate of relapse rate was 21% (95% CI 10.5%-40.3%) with moderate heterogeneity (I2=51%), being 35.9% (95% CI 17.3%-60.1%) in the 4 studies with rate of other organs involvement (OOI)>80% and as low as 10.1% (4.8%-20.3%) in the others. The pooled estimate of rituximab-related AEs was 25% (95% CI 8.8%53%) with substantial heterogeneity (I2=73.6%). There was no publication bias.

Conclusion:

Treatment of type I AIP with rituximab is associated with high remission rate, a higher relapse rate in presence of OOI and limited AEs. Randomized controlled trials with adequate power are needed to confirm these findings.

References:

[1]Lanzillotta M, Mancuso G, Della-Torre E. Advances in the diagnosis and management of IgG4 related disease. BMJ. 2020;369:m1067

[2]Lanzillotta M, Vinge-Holmquist O, Overbeek KA, et al. PrescrAIP: A Pan-European Study on Current Treatment Regimens of Auto-Immune Pancreatitis. Front Med (Lausanne). 2020;7:408

Disclosure of Interests:

None declared

POS1336 RETROPERITONEAL FIBROSIS IN ERDHEIM-CHESTER DISEASE HAS UNIQUE PRESENTING AND PROGNOSTIC FEATURES: A SINGLE CENTRE RETROSPECTIVE COMPARATIVE COHORT STUDY

Background:

Erdheim-Chester disease (ECD) is a multisystemic non-Langerhans cell histiocytosis. Retroperitoneal fibrosis (RPF) is a common ECD feature, found in up to 60% of patients. Besides ECD, RPF differential diagnosis includes other clinical entities of rheumatological interest, such as idiopathic RPF and IgG4-related disease (IgG4-RD). Since ECD management does not include glucocorticoids and mainly relies on the use of anti-neoplastic small molecules, a prompt diagnosis is critical.

Objectives:

To characterize the main differential clinical, radiologic and prognostic features of a monocentric cohort of patients with RPF. To provide practical learning points useful to recognize ECD among patients with RPF.

Methods:

Medical records of ECD patients with radiologic signs of RPF and of patients with non ECD-related RPF followed up at our Rheumatology Clinic were retrospectively reviewed. Final diagnosis relied either on analysis of histologic samples or on fulfilment of appropriate classification criteria. Main clinical, radiologic and laboratory features at diagnosis and long-term outcomes were evaluated and compared between the two groups. Non parametric tests were used for comparison.

Results:

31 (41%) ECD and 45 (59%) non-ECD patients (IgG4-RD, n=28; idiopathic RPF, n=11; peri-aortitis with large-vessel involvement, n=6) were included. All but one (97%) ECD patients and 56% non-ECD patients had a biopsy-proven diagnosis. ECD patients were younger at disease onset (51±14 vs 59±10 years, P=0.024) and diagnosed with a greater delay (48 [IQR, 13-92] vs 4 [IQR, 2-7] months, P<0.001). In the majority of ECD patients (84%), RPF was clinically silent and was disclosed in the context of the diagnostic work-up; conversely, 82% non-ECD patients had at least one RPF-related symptom (mainly, abdominal pain, n=19, and low-back pain, n=16). At diagnosis, C-reactive protein (50±34 vs 33±31 mg/L, P=0.052) and serum creatinine (1.31±0.53 vs 1.34±0.79, P=0.76) levels were not statistically different. In all ECD patients, fibrotic tissue surrounded both kidneys symmetrically, involving the ureters in half of the cases (Table 1); signs of hydronephrosis were present in 55% of patients (mostly bilaterally, 77%). In the non-ECD group, kidneys were rarely affected, and ureteral involvement was mostly asymmetric; hence, hydronephrosis incidence was similar (76%), but more frequently monolateral (65%). In non-ECD patients, fibrotic tissue more frequently involved inferior vena cava and iliac arteries. FDG uptake by RPF was disclosed in 39/40 (98%) non-ECD and 5/12 (42%) ECD patients who underwent a PET before therapy start (P<0.001). Ureteral stenting was required by a similar fraction of patients (ECD, 29%; non-ECD, 38%, P=0.47), but it was bilateral in 100% of ECD vs 29% of non-ECD patients (P<0.001). No differences in the rate of chronic kidney failure was found (26% vs 18%, P=0.41), but only ECD patients progressed to a terminal stage requiring hemodialysis (13% vs 0%, P=0.025).

Table 1.ECD patients (n=31)Non-ECD patients (n=45)P-valueLeft kidney30 (97%)4 (9%)<0.001Right kidney31 (100%)6 (13%)<0.001Left ureter16 (52%)16 (36%)0.24Right ureter16 (52%)24 (53%)1Abdominal aorta21 (68%)40 (89%)0.04Inferior vena cava5 (16%)29 (64%)<0.001Left iliac artery10 (32%)27 (60%)0.02Right iliac artery10 (32%)29 (64%)0.001Left renal artery9 (29%)6 (13%)0.14Right renal artery6 (19%)4 (9%)0.3Mesenteric artery8 (26%)4 (9%)0.06Celiac trunk7 (23%)3 (7%)0.08

Conclusion:

Our retrospective study suggests that ECD-related RPF has a significantly worse renal prognosis than non ECD-related RPF. A complete baseline work-up including a critical evaluation of the extension of the fibrotic tissue and the sites involved is fundamental to avoid patients’ misdiagnosis and mistreatment.

References:

[1]Campochiaro C, Tomelleri A, Cavalli, G, et al. Erdheim-Chester disease. Eur J Intern Med (2015)

[2]Lanzillotta M, Mancuso G, Della-Torre E. Advances in the diagnosis and management of IgG4 related disease. BMJ (2020)

Disclosure of Interests:

None declared

Respiratory Impairment Predicts Response to IL-1 and IL-6 Blockade in COVID-19 Patients With Severe Pneumonia and Hyper-Inflammation

BACKGROUND

Restraining maladaptive inflammation is considered a rationale strategy to treat severe coronavirus disease-19 (COVID-19) but available studies with selective inhibitors of pro-inflammatory cytokines have not provided unequivocal evidence of survival advantage. Late administration is commonly regarded as a major cause of treatment failure but the optimal timing for anti-cytokine therapy initiation in COVID-19 patients has never been clearly established.

OBJECTIVES

To identify a window of therapeutic opportunity for maximizing the efficacy of interleukin (IL)-1 and IL-6 blockade in COVID-19.

METHODS

Survival at the longest available follow-up was assessed in severe hyper-inflamed COVID-19 patients treated with anakinra, tocilizumab, sarilumab, or standard of care, stratified according to respiratory impairment at the time of treatment initiation.

RESULTS

107 patients treated with biologics and 103 contemporary patients treated with standard of care were studied. After a median of 106 days of follow-up (range 3-186), treatment with biologics was associated with a significantly higher survival rate compared to standard therapy when initiated in patients with a PaO₂/FiO₂ ≥ 100 mmHg (p < 0.001). Anakinra reduced mortality also in patients with PaO₂/FiO₂ < 100 mmHg (p = 0.04).

CONCLUSIONS

IL-1 and IL-6 blocking therapies are more likely to provide survival advantage in hyper-inflamed COVID-19 patients when initiated before the establishment of severe respiratory failure.

Emerging therapy options for IgG4-related disease

INTRODUCTION

Awareness of IgG4-related disease (IgG4-RD) is increasing worldwide and specialists are now familiar with most of its clinical manifestations and mimickers. IgG4-RD promptly responds to glucocorticoids and repeated courses are typically used to induce and maintain remission because the disease relapses in most patients. If left untreated, it can lead to organ dysfunction, organ failure and death. Advancement in our understanding of IgG4-RD pathogenesis is leading to the identification of novel therapeutic targets and emerging treatments are now setting the stage for personalized therapies for the future.

AREAS COVERED

This review focuses on emerging treatment options for IgG4-RD based on our advancing understanding of disease pathophysiology. Research was performed in the English literature on Pubmed and clinicaltrials.gov databases.

EXPERT OPINION

Glucocorticoids remain the first-line induction treatment for the multi-organ manifestations of IgG4-RD. Alternative immunosuppressive agents for maintaining remission are warranted in order to avoid long-term steroid toxicity, and to offer a more mechanistic and personalized therapeutic strategy. Targeting B and T-lymphocyte activation represents the most promising approach, but randomized controlled trials are eagerly awaited to confirm positive preliminary experiences reported in case series and small cohort studies.

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 (Truxima^TM) rituximab biosimilar CT-P10 represents a safe and effective alternative to rituximab originator for the treatment of IgG4-RD.

Mer tyrosine kinase (MerTK) as a possible link between resolution of inflammation and tissue fibrosis in IgG4-related disease

OBJECTIVES

IgG4-related disease (IgG4-RD) is a systemic fibro-inflammatory disorder characterized by a dysregulated resolution of inflammation and wound healing response that might develop after an apoptotic insult induced by cytotoxic T lymphocytes (CTLs). Mer receptor tyrosine kinase (MerTK) and its ligand Protein S (ProS1) have a pivotal role in the resolution of inflammation, being implicated in the clearance of apoptotic cells, quenching of the immune response and development of tissue fibrosis. In the present work we aimed to investigate a possible involvement of the MerTK signalling pathway in the pathogenesis of IgG4-RD and development of tissue fibrosis.

METHODS

MerTK and ProS1 expression patterns in IgG4-RD lesions were evaluated by immunohistochemistry and immunofluorescence studies. Circulating MerTK+ monocytes, soluble Mer and MerTK ligands were measured in the peripheral blood of IgG4-RD patients and healthy controls by flow cytometry and ELISA, respectively.

RESULTS

MerTK was highly expressed by macrophages infiltrating IgG4-RD lesions. MerTK+ macrophages were more abundant in IgG4-RD than in Sjögren syndrome and interacted with apoptotic cells and ProS1 expressing T and B lymphocytes. Moreover, they expressed the pro-fibrotic cytokine TGF-β and their numbers declined following rituximab induced disease remission. Circulating MerTK+ monocytes, soluble Mer and MerTK ligands were not increased in the peripheral blood of patients with IgG4-RD.

CONCLUSIONS

The MerTK-ProS1 axis is activated in IgG4-RD lesions, possibly leading to persistent stimulation of processes involved in the resolution of inflammation and tissue fibrosis.

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.

Interleukin-6 blockade with sarilumab in severe COVID-19 pneumonia with systemic hyperinflammation: an open-label cohort study

OBJECTIVES

To assess the safety and efficacy of interleukin (IL)-6 blockade with sarilumab in patients with severe COVID-19 pneumonia and systemic hyperinflammation.

METHODS

We conducted an open-label study of sarilumab in severe COVID-19 pneumonia (PaO₂/FiO₂ <300 mm Hg) with hyperinflammation (elevated inflammatory markers and serum IL-6 levels). Sarilumab 400 mg was administered intravenously in addition to standard of care and results were compared with contemporary matched patients treated with standard of care alone. Clinical improvement, mortality, safety and predictors of response were assessed at 28 days.

RESULTS

Twenty-eight patients were treated with sarilumab and 28 contemporary patients receiving standard of care alone were used as controls. At day 28 of follow-up, 61% of patients treated with sarilumab experienced clinical improvement and 7% died. These findings were not significantly different from the comparison group (clinical improvement 64%, mortality 18%; p=NS). Baseline PaO₂/FiO₂ ratio >100 mm Hg and lung consolidation <17% at CT scan predicted clinical improvement in patients treated with sarilumab. Median time to clinical improvement in patients with lung consolidation <17% was shorter after sarilumab (10 days) than after standard treatment (24 days; p=0.01). The rate of infection and pulmonary thrombosis was similar between the two groups.

CONCLUSIONS

At day 28, overall clinical improvement and mortality in patients with severe COVID-19 were not significantly different between sarilumab and standard of care. Sarilumab was associated with faster recovery in a subset of patients showing minor lung consolidation at baseline.

PrescrAIP: A Pan-European Study on Current Treatment Regimens of Auto-Immune Pancreatitis

Introduction: Treatment of autoimmune pancreatitis (AIP) is based solely on consensus and has yet to become standardized. Consequently, therapeutic regimens vary greatly between countries and centers, and largely depend on the experience of the physician. At this moment, the optimal regimen for inducing disease remission and preventing relapse is unknown. Objectives: The primary objective of this study is to describe current treatment regimens used in Europe, and to compare their effectiveness in inducing remission and preventing and treating relapse. The secondary objectives are: to identify risk factors for relapse; to assess the diagnostic accuracy of the Unified-AIP criteria; to assess the performance of the M-ANNHEIM score for predicting relapse; and to assess long-term outcomes including pancreatic exocrine insufficiency and pancreatic cancer. Methods: This is an international, retrospective, observational cohort study, performed in over 40 centers from 16 European countries. Eligible are all patients diagnosed with AIP from 2005 onwards, regardless of the used diagnostic criteria. Data on study subjects will be retrieved from the hospital's electronic medical records and registered with a standardized, web-based, electronic case report form (eCRF). To compare the effectiveness of treatment regimens in inducing remission, preventing relapse, and treating relapse, subjects will be stratified in groups based on: type of therapy; initial therapy dose; cumulative therapy dose; therapy tapering speed and duration; and having received maintenance therapy or not. Ethics and Dissemination: Ethical and/or institutional review board approvals are obtained by all participating centers according to local regulations. The study complies with the General Data Protection Regulation (GDPR). All manuscripts resulting from the study will be submitted to peer-reviewed journals. Conclusion: This is the first pan-European retrospective registry for AIP. It will produce the first large-scale data on treatment of European patients with AIP, providing answers on the use and effectiveness of treatment regimens. In the future, this collaboration may provide a network for continuation into a prospective European registry.

Urgent manifestations of immunoglobulin G4-related disease

Objective: Immunoglobulin G₄-related disease (IgG₄-RD) is considered a chronic condition with insidious presentation, but clinical experience suggests that disease onset prompts admission to the emergency department (ED) in a sizeable proportion of patients. We assessed the prevalence of acute manifestations associated with IgG₄-RD onset requiring referral to the ED. Method: We revised our database and identified patients admitted to the ED because of symptoms latterly attributed to IgG₄-RD onset (Group 1) and those who were referred to our outpatient clinic without previous urgent manifestations (Group 2). Acute manifestations were clustered based on the anatomical region affected by IgG₄-RD. Epidemiological, clinical, and serological features of Groups 1 and 2 were compared. Results: The study included 141 patients with IgG₄-RD. Of these, 76 (54%) presented to the ED at disease onset. The most common clinical manifestations requiring admission to the ED were jaundice (53%), abdominal pain (41%), and fever (10%). Gastrointestinal involvement was the most frequent cause of referral to the ED (71% of cases), followed by involvement of the retroperitoneum (14.5%) and the nervous system (6.6%). Pancreatobiliary involvement was significantly more frequent in Group 1 than in Group 2. Head and neck, and salivary and lacrimal gland involvement was more frequent in Group 2 than in Group 1. The diagnostic delay was significantly shorter in Group 1 than in Group 2. Conclusion: Clinical manifestations associated with IgG₄-RD onset require referral to the ED in most cases. This finding contrasts with the general view of IgG₄-RD as a condition with non-acute presentation.

B lymphocytes contribute to stromal reaction in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is characterized by a prominent stromal reaction that has been variably implicated in both tumor growth and tumor suppression. B-lymphocytes have been recently implicated in PDAC progression but their contribution to the characteristic stromal desmoplasia has never been assessed before. In the present work, we aimed to verify whether B-lymphocytes contribute to stromal cell activation in PDAC. CD19⁺ B-lymphocytes purified from peripheral blood of patients with PDAC were cultivated in the presence of human pancreatic fibroblasts and cancer-associated fibroblasts. Released pro-fibrotic soluble factors and collagen production were assessed by ELISA and Luminex assays. Quantitative RT-PCR was used to assess fibroblast activation in the presence of B cells. The expression of selected pro-fibrotic and inflammatory molecules was confirmed on PDAC tissue sections by multi-color immunofluorescence studies. We herein demonstrate that B-cells from PDAC patients (i) produce the pro-fibrotic molecule PDGF-B and stimulate collagen production by fibroblasts; (ii) express enzymes implicated in extracellular matrix remodeling including LOXL2; and (iii) produce the chemotactic factors CCL-4, CCL-5, and CCL-11. In addition we demonstrate that circulating plasmablasts are expanded in the peripheral blood of patients with PDAC, stimulate collagen production by fibroblasts, and infiltrate pancreatic lesions. Our results indicate that PDAC is characterized by perturbations of the B-cell compartment with expansion of B-lymphocyte subsets that directly contribute to the stromal reaction observed at disease site. These findings provide an additional rationale for modulating B-cell activity in patients with pancreatic cancer.

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 &lt; 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.

AB0154 MERTK AND THE RESOLUTION OF INFLAMMATION IN IGG4-RELATED DISEASE

Background:

IgG4-Related Disease (IgG4-RD) is characterized by fibrotic lesions, serum IgG4 elevation, and prompt response to glucocorticoids. B and T lymphocytes are considered the initiators of tissue inflammation in IgG4-RD, but the prominent stromal reaction observed at disease sites suggest that a dysregulation of processes involved in the resolution of inflammation could be pathologically relevant as well. Mer receptor tyrosine kinase (MerTK) and its ligands protein S (Pros1) have a pivotal role in the resolution of inflammation through the activation of a well-characterized signaling pathway that ultimately dampens the immune response and promotes the recovery of tissue function. MerTK and the processes involved in the resolution of inflammation have never been addressed in IgG4-RD.

Objectives:

To investigate MerTK involvement in the pathogenesis of IgG4-RD by evaluating (a) the expression of MerTK and of its endogenous ligands in IgG4-RD tissues; (b) the presence of circulating precursors of MerTK+ cells infiltrating IgG4-RD lesions in the peripheral blood of IgG4-RD patients; (c) the effects of immunosuppressive therapies on MerTK expression in IgG4-RD tissues.

Methods:

Three distinct cohorts of IgG4-RD patients were included in this study. 8 active patients were used for immunohistochemistry studies for MerTK expression. 16 IgG4-RD and 14 Sjögren syndrome patients, together with 6 control tonsils, were used for multicolor immunofluorescence studies and TissueQuest software quantification of the expression of MerTK, CD68, CD163, Pros1, Gas6, CD4, SLAMF7, CD19, IgG4, cleaved caspase-3. 10 untreated IgG4-RD patients were used to evaluate MerTK expression in circulating monocytes subsets and fibrocytes by flow cytometry.

Results:

MerTK was highly expressed in IgG4-RD affected organs. MerTK+ cells accounted on average for 16% (range 5-35%) of all cells in the tissue, and the majority of them expressed CD68,reflecting a monocyte-macrophage origin. 33.5 % (interquartile range (IQR) 26-41%) of MerTK+ cells co-expressed CD68 and CD163, while 30.5% (IQR 19-41.5%) expressed CD68 but not CD163. CD68+MerTK+ cells displayed two main morphological appearances, compatible with those of macrophages and of myofibroblasts. In addition, MerTK+ cell number was significantly increased in salivary glands from IgG4-RD patients compared to Sjögren syndrome (p < 0.0001). Circulating precursors of CD68+MerTK+ cells infiltrating IgG4-RD lesions were identified by flow cytometery in the peripheral blood of patients with active IgG4-RD as MerTK+ populations of intermediate monocytes, nonclassical monocytes and collagen expressing fibrocytes. MerTK ligand Pros1 was exposed on 52% (IQR 42-57%) of infiltrating B lymphocytes, 74% (IQR 54-89%) of infiltrating T lymphocytes, and, likely, on apoptotic cells that were detected in IgG4-RD tissues. CD68+MerTK+ cells were found in physical contact with Pros1+ cells in IgG4-RD lesions and their number decreased by 56% after successful treatment with rituximab.

Conclusion:

MerTK is abundant in IgG4-RD affected organs and is preferentially expressed on CD68+ macrophages and myofibroblasts that infiltrate IgG4-RD lesions. MerTK+ cells might interact with apoptotic cells and Pros1 expressing T and B lymphocytes in IgG4-RD tissues, leading to the persistent activation of processes involved in the resolution of inflammation and promoting the development of tissue fibrosis.

Disclosure of Interests:

None declared

SAT0528 CLINICAL PHENOTYPES OF IGG4-RELATED DISEASE REFLECT DIFFERENCES IN EPIDEMIOLOGICAL FEATURES, SEROLOGICAL FINDINGS, AND PROGNOSTIC OUTCOMES

Background:

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); Mickulicz/Systemic (Group 4) - but the relevance of this classification for patient management remains unknown (1,2).

Objectives:

We aimed to assess whether clinical judgment can replicate LCA classification and to evaluate potential differences in epidemiological features, serological findings, and disease outcomes between disease phenotypes.

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 judgment. Agreement between LCA and clinical clustering was calculated. To assess differences among disease phenotypes, the following variables were recorded on additional 139 patients: serum IgG4 and IgE; inflammatory markers; eosinophils; plasmablasts; IgG4-RD Responder Index (RI); history of atopy, diabetes, osteoporosis, relapses, and tumors; cumulative dose of glucocorticoids and use of rituximab.

Results:

Clinical judgment recapitulated LCA classification with strong agreement between IgG4-RD experts (κ= 0.841, p < 0.0005). Group 1 showed the highest levels of serum IgG4 and IgE. Group 2 and 4 had the lowest and highest IgG4-RD RI, respectively (Table 1). Increased cumulative doses of glucocorticoids and higher relapse rate were observed in Group 3 (Fig 1). A higher incidence of diabetes mellitus was observed in Group 1 and 4.

Table 1

Clinical and serological characteristics of patients cohort.

Group 1(59 pts - 45%)Group 2(29 pts - 22%)Group 3(25 pts - 19%)Group 4(18 pts - 14%)P valueFemale n° (%)12 (20%)8 (28%)11 (44%)5 (28%)0.18Age67 (61-73)61 (56-70)52 (40-62)57 (51-62)<0.0001Serum IgG4 (mg/dL)331 (184-575)155 (49-258)150 (80-255)282 (166-460)0.0009IgG4-RD RI9 (6-9)6 (6-9)9 (6-12)9 (6-13)0.004Definite diagnosis n° (%)20 (34%)18 (62%)20 (80%)10 (55%)0.0008Probable diagnosis n° (%)1 (0.59%)0 (0%)1 (0.19%)1 (0.14%)0.6Possible diagnosis n° (%)38 (64%)10 (34%)4 (16%)7 (39)0.0003Emergency Department n° (%)37 (63%)14 (48%)7 (28%)10 (55%)0.03History of atopy n° (%)7 (12%)4 (14%)7 (28%)6 (23%)0.09ESR (mm/h)20 (8-39)40 (14-59)38 (14-54)12 (8-21)0.04CRP (mg/L)5 (2-8)10 (3-52)8 (3-28)3 (2-6)0.03Eosinophils (cell/mm3)200 (200-500)200 (100-275)300 (200-475)200 (100-500)0.3IgE (U/mL)283 (97-723)69 (28-264)120 (41-412)219 (54-657)0.02Plasmablast (cell/mL)1765 (627-4000)1890 (1020- 4000)2000 (370- 4780)2690 (140-5130)0.99Diagnostic delay (months)4 (2-9)7 (4-12)10 (3-18)11 (2-38)0.04Starting prednisone dose(mg, range)60 (37-70)50 (40-75)65 (40-90)40 (30-70)0.8Diabetes at disease onset10 (17%)1 (3%)2 (8%)2 (11%)0.09Figure 1.

Relapse free survival of the four different IgG4-RD phenotypes.

Conclusion:

Clinical phenotypes of IgG4-RD reflect differences in epidemiological features and prognostic outcomes.

References:

[1]Bledsoe JR, Della-Torre E, Rovati L, Deshpande V. IgG4-related disease: review of the histopathologic features, differential diagnosis, and therapeutic approach. APMIS. 2018;126:459-476.

[2]Wallace ZS, Zhang Y, Perugino CA, Naden R, Choi HK, Stone JH; ACR/EULAR IgG4-RD Classification Criteria Committee. Clinical phenotypes of IgG4-related disease: an analysis of two international cross-sectional cohorts. Ann Rheum Dis. 2019;78:406-412.

Disclosure of Interests:

Marco Lanzillotta: None declared, Emanuel Della Torre: None declared, Corrado Campochiaro Speakers bureau: Novartis, Pfizer, Roche, GSK, SOBI, Gaia Mancuso: None declared, Lorenzo Dagna Grant/research support from: The Unit of Immunology, Rheumatology, Allergy and Rare Diseases (UnIRAR) received unresctricted research/educational grants from Abbvie, Bristol-Myers Squibb, Celgene, Janssen, Merk Sharp & Dohme, Mundipharma Pharmaceuticals, Novartis, Pfizer, Roche, Sanofi-Genzyme, and SOBI., Consultant of: Prof Lorenzo Dagna received consultation honoraria from Abbvie, Amgen, Biogen, Bristol-Myers Squibb, Celltrion, Novartis, Pfizer, Roche, Sanofi-Genzyme, and SOBI.

AB1047 IgG4-RELATED DISEASE PRESENTATION REQUIRES ADMISSION TO THE EMERGENCY DEPARTMENT IN THE MAJORITY OF CASES

Background:

IgG4-related disease (IgG4-RD) is generally considered a chronic fibro-inflammatory condition with insidious presentation and subclinical course. Our clinical experience, however, suggests that a sizable proportion of patients experience multiple accesses to the emergency department (ED), either at disease onset or during the disease course.

Objectives:

In the present study we aimed (i) to assess the prevalence of acute manifestations of IgG4-RD at disease onset requiring referral to the ED, and (ii) to calculate the diagnostic delay from the initial acute presentation.

Methods:

We revised our database and identified patients admitted to the ED because of symptoms lately attributed to IgG4-RD onset (Group 1) and those that were referred to our outpatient clinic without previous urgent manifestations (Group 2). Acute manifestations were clustered based on the anatomical district affected by IgG4-RD. Epidemiological, clinical, and serological features of Group 1 and Group 2 were compared.

Results:

The study included 141 patients with IgG4-RD. 76 (54%) presented to the ED at disease onset. The most common clinical manifestations requiring admission to the ED were jaundice (53%), abdominal pain (41%), and fever (10%). Gastrointestinal involvement was the most frequent cause of referral to the ED (71% of cases), followed by involvement of the retroperitoneum (14.5%), and of the nervous system (6.6%). Pancreato-biliary involvement was significantly more frequent in Group 1. Head, neck, salivary and lacrimal gland involvement was more frequent in Group 2. The diagnostic delay was significantly shorter in Group 1 than in Group 2.

Conclusion:

Clinical manifestations associated with IgG4-RD onset require referral to the ED in the majority of cases. This finding contrasts with the general view of IgG4-RD as a condition with non-acute presentation.

References:

[1]Bledsoe JR, Della-Torre E, Rovati L, Deshpande V. IgG4-related disease: review of the histopathologic features, differential diagnosis, and therapeutic approach. APMIS. 2018;126:459-476.

[2] Della-Torre E, Lanzillotta M, Doglioni C. Immunology of IgG4-related disease. Clin Exp Immunol.2015;181:191-206.

[3]Lanzillotta M, Campochiaro C, Trimarchi M, Arrigoni G, Gerevini S, Milani R, et al. Deconstructing IgG4-related disease involvement of midline structures: Comparison to common mimickers. Mod Rheumatol. 2017;27:638-645.

[5]Della-Torre E, Stone JH. “How I manage” IgG4-Related Disease. J Clin Immunol. 2016;36:754-763.

[6]Perugino CA, Mattoo H, Mahajan VS, Maehara T, Wallace ZS, Pillai S, et al. Emerging Treatment Models in Rheumatology: IgG4-Related Disease: Insights Into Human Immunology and Targeted Therapies. Arthritis Rheumatol. 2017;69:1722-1732.

[7]Stone JH, Zen Y, Deshpande V. IgG4-related disease. N Engl J Med. 2012;366:539-51.

[8]Kamisawa T, Zen Y, Pillai S, Stone JH. IgG4-related disease. Lancet. 2015;385:1460-71

[9]Umehara H, Okazaki K, Masaki Y, Kawano M, Yamamoto M, Saeki T, et al. Comprehensive diagnostic criteria for IgG4-related disease (IgG4-RD), 2011. Mod Rheumatol. 2012;22:21-30.

Disclosure of Interests:

Gaia Mancuso: None declared, Emanuel Della Torre: None declared, Marco Lanzillotta: None declared, Giuseppe Alvise Ramirez: None declared, Lorenzo Dagna Grant/research support from: The Unit of Immunology, Rheumatology, Allergy and Rare Diseases (UnIRAR) received unresctricted research/educational grants from Abbvie, Bristol-Myers Squibb, Celgene, Janssen, Merk Sharp & Dohme, Mundipharma Pharmaceuticals, Novartis, Pfizer, Roche, Sanofi-Genzyme, and SOBI., Consultant of: Prof Lorenzo Dagna received consultation honoraria from Abbvie, Amgen, Biogen, Bristol-Myers Squibb, Celltrion, Novartis, Pfizer, Roche, Sanofi-Genzyme, and SOBI.

Long-term efficacy of maintenance therapy with Rituximab for IgG4-related disease

BACKGROUND

IgG4-Related Disease (IgG4-RD) promptly responds to glucocorticoids but relapses in most patients. Rituximab (RTX) represents a promising strategy to avoid IgG4-RD flares but its administration for maintaining disease remission has never been assessed in terms of optimal timing of infusion, dosage, and duration of treatment. In the present study we aimed to evaluate the efficacy and safety of RTX for maintenance of IgG4-RD remission.

METHODS

Fourteen patients with IgG4-RD were treated with RTX as induction of remission therapy at the San Raffaele Scientific Institute in Milan, Italy. The cohort was then divided into two study groups: patients re-treated only in case of disease relapse (Group 1, n = 7), and patients regularly re-treated with RTX every 6 months for maintenance therapy (Group 2, n = 7). Data on free-relapse rate and adverse events were collected and retrospectively analysed.

RESULTS

Median follow-up time and baseline clinical-serological features were similar between Group 1 and 2 (p > 0.05). The free relapse rate 18 months after induction of remission treatment was significantly lower in Group 1 (29%) than in Group 2 (100%) (p = 0.006). Infectious complications developed in 6/14 patients (3 in Group 1 and 3 in Group 2).

CONCLUSION

Administration of RTX every 6 months as maintenance of remission therapy prevents IgG4-RD flares.

The 2019 American College of Rheumatology/European League Against Rheumatism classification criteria for IgG4-related disease

IgG4-related disease (IgG4-RD) can cause fibroinflammatory lesions in nearly any organ. Correlation among clinical, serological, radiological and pathological data is required for diagnosis. This work was undertaken to develop and validate an international set of classification criteria for IgG4-RD. An international multispecialty group of 86 physicians was assembled by the American College of Rheumatology (ACR) and the European League Against Rheumatism (EULAR). Investigators used consensus exercises; existing literature; derivation and validation cohorts of 1879 subjects (1086 cases, 793 mimickers); and multicriterion decision analysis to identify, weight and test potential classification criteria. Two independent validation cohorts were included. A three-step classification process was developed. First, it must be demonstrated that a potential IgG4-RD case has involvement of at least one of 11 possible organs in a manner consistent with IgG4-RD. Second, exclusion criteria consisting of a total of 32 clinical, serological, radiological and pathological items must be applied; the presence of any of these criteria eliminates the patient from IgG4-RD classification. Third, eight weighted inclusion criteria domains, addressing clinical findings, serological results, radiological assessments and pathological interpretations, are applied. In the first validation cohort, a threshold of 20 points had a specificity of 99.2% (95% CI 97.2% to 99.8%) and a sensitivity of 85.5% (95% CI 81.9% to 88.5%). In the second, the specificity was 97.8% (95% CI 93.7% to 99.2%) and the sensitivity was 82.0% (95% CI 77.0% to 86.1%). The criteria were shown to have robust test characteristics over a wide range of thresholds. ACR/EULAR classification criteria for IgG4-RD have been developed and validated in a large cohort of patients. These criteria demonstrate excellent test performance and should contribute substantially to future clinical, epidemiological and basic science investigations.