AUTOIMMUNE CHOLESTATIC LESIONS OF BILIARY DUCTS

The review presents literature data and original findings of light and electron microscopy of pathomorphological changes in the bile ducts in primary sclerosing cholangitis (PSC), immunoglobulin G4 (IgG4)-associated autoimmune sclerosing cholangitis and overlap syndromes: PSC + chronic autoimmune hepatitis (AIH); PSC + primary biliary cirrhosis (PBC).

AB0440 CLINICAL AND IMMUNOLOGICAL FEATURES OF THE SYSTEMIC SCLEROSIS-OVERLAP SYNDROMES

Background:Systemic Sclerosis (SSc) overlap syndromes (SSc with polymyositis / dermatomyositis (PM/DM), rheumatoid arthritis (RA), etc.) still remain a group of very heterogenous and not very well studied clinical variants of SSc that are characterized by certain clinical and immunological features.Objectives:Identify clinical and immunological features of the SSc-overlap syndromesMethods:80 pts with SSc-PM/DM and 35 pts with SSc-RA undergoing standard clinical examination and laboratory immunological evaluation.Results:ANA Hep2 was positive in 98% of SSc-PM/DM pts; a-Scl-70 was in 34%, a - PM-Scl and RF were in 20%. ACA (6%), a-RNP (9%), and a - Jo-1 (5%) were significantly less common. Correlation analysis showed significant prevalence of conduction abnormalities in pts with a-Scl-70- (p<0.03); PM-Scl was rarely associated with cardiac arrhythmia (p<0.02) and pericarditis (p<0.03), but there was an association between ACA and presence of digital ischemia (p<0.04). Three pts with limited skin had Scl-70 and PM-Scl antibodies, two of them manifested clinical features of DM. A-Jo-1 was found in 3 pts with a longstanding disease (14,10 and 7 years), and one of these pts was also positive for a-Scl-70. All pts had limited skin and two had interstitial lung disease with FVC values of 79% and 74.8%.ANA Hep2 was positive in 96% of SSc-RA pts; a-Scl-70 – in 28%, and a-RNP - in 30%. RF-positivity was in 72% of pts, and Anti-CCP - in 27%. Simultaneous Anti-CCP and a-Scl-70 was found in one case, and Anti-CCP - anti-RNP – in another, both were associated with low RF titers. All pts had early joint involvement which became prevailing in subsequent years, and onset of the disease between 30 and 36 years. There was a correlation between laboratory signs of inflammatory activity and immunological disorders: ESR and a-Scl-70 (p<0.03). Anti-CCP and a-Scl-70 co-positivity was a significantly less frequent phenomenon (p<0.04). There was a remarkable 28% proportion of a-Scl-70 cases in SSc-RA with limited cutaneous which is usually characterized by ACA-positivity.Conclusion:SSc-PM/DM and SSc-RA appear to be an active disease from the immunological point of view, confirming therefore an important role of immune alterations in disease progression. Laboratory findings display specific pathogenetic features of SSc-overlap syndromes; laboratory abnormalities can be used to measure the activity and specify characteristics of the pathological process.Disclosure of Interests:None declared

AB0726 BIOLOGICS IN CHILDREN WITH IDIOPATHIC INFLAMMATORY MYOPATHIES: AN EXPERIENCE OF SINGLE CENTER

Background:Juvenile dermatomyositis (JDM) is the most common idiopathic inflammatory myopathy (IIM) of childhood, but the involvement of muscle also can be complication of systemic lupus erythematosus (SLE), mixed connective tissue disease (MCTD) and different overlap syndromes. The presence of myopathy can significantly affect the prognosis of the disease and the quality of life. Despite of the absence of official indication for biological therapy fo IIM, it`s may be needed in severe course of disease.Objectives:To analyze in retrospective study the efficacy and safety of Biologics (B) in patients (pts) with IIM in our pediatric rheumatology center.Methods:The study included all pts with rheumatic diseases (RD), who had IIM and received B during past 10 years.Results:A total of 17 pts (10 females) were identified: 23.5% with JDM, 11.8% - SLE, 35.3% - MCTD, 29.4% - overlap syndromes. The median age at the onset of RD was 9.75 years [interquartile range (IQR) 6.9; 13.5]. The median disease duration at the onset of myopathy was 7.0 months [3.0; 10.0], in all pts with JDM – at onset. All pts had myopathic syndrome. The rash tipical for JDM was in 8 pts (47%). The lung involvement observed in 6 pts (35.3%). Levels of serum muscle enzymes (CK, ALT, AST and lactate dehydrogenase [LDH]) were elevated in 88.2% of pts: CK in 52.9% (mean ± std 624.35±1007.2 U/L), ALT – 82.4% (mean ± std 142.18±148.16U/L), AST – 82.4% (mean ± std 159.6±201.1 U/L), LDH – 88.2% (mean ± std 492.5±229.2 U/L). Abnormal EMG findings were in 10 pts (59.4%). Nailfold capillaroscopic changes tipical for IIM had 10 pts (59.4%). Before B 94.1% of pts received corticosteroids (CS), 58.8% - methotrexate, 29.4% - hydroxychloroquine, 17.6% - cyclophosphamide, 11.8% - cyclosporine, 5.9% - mycophenolate mofetil, 5.9% - azathioprine, 47% - IVIG. B therapy was started due to insufficient efficacy of previous therapy. The median age at start of B was 12.3 years [IQR 9.5; 15.0]. The median disease duration prior to treatment with B was 2.25 years [IQR 0,8; 3.6]. 58.8% of pts received rituximab (RTX), 41.2% - abatacept (ABA). The median time between each course of RTX was 182 days [IQR 156–315]. 80% of pts underwent more than one course of RTM therapy, with a maximum of 5 courses. The median duration of ABA therapy was 2.8 years [IQR 1.6; 5.0]. Discontinuation of B due to serious AE was observed in 1 patient with overlap syndrome (5.9%) – macrophage activation syndrome (MAS) 8 day after RTX infusion (5th course, 1st infusion). One patient (female, 12.3 yo) died from MAS (at onset of SLE, developed before B), the others achieved remission. B therapy allowed to reduce the dose of CS to maintenance in all pts, decrease of calcinosis in 2 pts and improve the quality of life.Conclusion:Our study demonstrated that B is highly effective in children with IIM and have the acceptable safety. Early diagnosis and initiation of intensive therapy are important in reducing symptoms of myopathy in RD. It seems that the development of IIM in other RDs, not JDM, indicates the need for B and its good efficacy. The further extended studies are needed.Disclosure of Interests:None declared

Usefulness of Osmolar Excretion Rate in the Diagnosis of Fluids and Electrolytes Overlap Syndromes

Clinical practice related to electrolytes and acid-base disorders is commonly approached as a single entity. Overlap syndromes are an uncommon clinical condition that must be considered as part of differential diagnosis when a patient is assessed. The coexistence of electrolytic disorders could make it difficult to interpret certain variables due to the influence of such disorders on the same variable, even in the opposite way. In this context, there are some tools that are very useful in order to establish the correct diagnosis. Thus, osmole excretion rate, tonicity balance, and estimation of electrolyte-free water balance should be considered along with other biochemical variables in order to increase the possibility to make a correct interpretation.

Genetic Aspects of Myelodysplastic/Myeloproliferative Neoplasms

Myelodysplastic/myeloproliferative neoplasms (MDS/MPN) are myeloid neoplasms characterized by the presentation of overlapping features from both myelodysplastic syndromes and myeloproliferative neoplasms. Although the classification of MDS/MPN relies largely on clinical features and peripheral blood and bone marrow morphology, studies have demonstrated that a large proportion of patients (~90%) with this disease harbor somatic mutations in a group of genes that are common across myeloid neoplasms. These mutations play a role in the clinical heterogeneity of these diseases and their clinical evolution. Nevertheless, none of them is specific to MDS/MPN and current diagnostic criteria do not include molecular data. Even when such alterations can be helpful for differential diagnosis, they should not be used alone as proof of neoplasia because some of these mutations may also occur in healthy older people. Here, we intend to review the main genetic findings across all MDS/MPN overlap syndromes and discuss their relevance in the management of the patients.