Potential options of clinical evaluation in patients with ANCA-associated systemic vasculitis

Kuzmina G.P.

• Dnipro State Medical University

Summary. The lack of an appropriate biomarker to detect a recurrent or persistent disease creates a risk of increased morbidity, relapses and mortality due to restriction of disease control or negative impact on the patient of potentially dangerous therapy. The purpose of the study: to study data on the identification of several new markers — candidates based on the study of innovative analytical tools, improving understanding of the basis of immunopathogenesis and the ultimate goal of trea­ting ANCA-associated vasculitis. Materials and methods. This paper presents problematic issues related to the role of the ANCA in ANCA-associated vasculitis with an emphasis on the features of the clinical phenotypes of PR3 and MPO-ANCA carriers, relapses based on information searches conducted in Medline and PubMed published in the last 3 decades. Results and discussions. Over the past 25 years, a significant progress has been made in the development of a technique for the detection of antinetrophilic cytoplasmic antibodies (ANCA). This applies to advances in antigen characterization, standardization of ANCA analyses, inclusion of ANCA in nomenclature and classification propo­sals, and anCA technology. The consensus statements regarding the ANCA testing had some justification given the different variations in relation to their evaluation. The discovery of ANCA among patients with clinical HPA or IPA syndromes was an important step in the diagnosis and treatment of the condition. In accordance with international documents with the definition and evaluation of ANCA test results, when determining this group of autoantibodies in all patients, the method of reaction of immune fluorescence (RNIF) is used. Recently, the specificity of ANCA to PR3 or MPO has been recommended for the purpose of classifying diseases. This is due to the fact that the difference in genetics, pathogenesis, risk factors, treatment re­sponses and results are more consistent with type PR3 or MPO-ANCA, in a non-clinical diagnosis. The risk of relapse is more closely rela­ted to the type of disease, rather than the type of ANCA. In MRO-ANCA+ patients with GPA, the frequency of relap­ses is the same as in PR3- ANCA+ in patients with GPA. When changing the treatment strategy, it is necessary to rely on a comprehensive clinical examination, and not on the results of the ANCA defi­nition. The value of an ANCA as a predictor of relapse has not been determined and has not been proven, negative results of an ANCA tests do not exclude the presence of an active phase of the di­sease. A regular comprehensive clinical evaluation of the patient’s condition is recommended, for which it is proposed to use such highly informative clinical indices as BVAS, damage index (VDI), disease degree (Disease Extent Index) and 5-factor scale (Five Factor Score). Conclusions. The lack of an appropriate biomarker to detect a recurrent or persistent disease creates a risk of increased morbidity, relapses and mortality due to restriction of disease control or negative impact on the patient of potentially dangerous therapy. Thus, there is a need to develop a functional biomarker that will meet the risks stratification and personification of treatment. Activation of an alternative pathway of the compliment is fundamental for the development of the disease, and the decomposition products in the urine are the potentіal biomarker of kidney vasculitis.