Granulomatosis with polyangitis. Etiology, diagnosis and treatment

 Donata Vaičiulytė1, Miglė Jurgelėnaitė1, Miglė Vitartaitė1

1 Lithuanian University of Health Sciences, Faculty of Medicine

Kaunas, Lietuva

Abstract

Granulomatosis with polyangiitis (GPA) is a rare systemic autoimmune disease that affects small and medium sized blood vessels.  The prevalence of GPA is 148,1 cases per 1 000 000 inhabitants, it is more common among people of Northern European descent. The exact etiology of this pathology is unknown, but it is thought that genetic predisposition has the biggest influence in the development of GPA. Other GPA risk factors include infectious, environmental, chemical, toxic, pharmacological irritants and immune system disorders. The pathogenesis of GPA is a complex process that involves the formation of anti-neutrophil cytoplasmic antibodies (ANCA). Approximately 80% of GPA patients develop ANCA against proteinase-3 (PR3) and 10% of patients develop ANCA against myeloperoxidase (MPO). The pathology is classified according to GPA classification criteria developed by the American College of Rheumatology in 1990. GPA can cause a wide variety of symptoms. The most commonly occurring symptoms are related to upper and lower respiratory tract as well as kidney damage. Patients may develop rapidly progressive renal failure, granulomatous inflammation, pulmonary nodules and alveolar hemorrhage. 50% of patients develop systemic symptoms – fewer, weight loss, fatigue. Diagnosing GPA is important to differentiate it from other systemic vasculitides. Various tests are performed: blood tests, immunological tests, urine tests and radiological tests. Biopsies can be also performed. Prompt and high-quality diagnosis of GPA is an important factor in the prognosis of the disease, as the morbidity and mortality rates are greatly reduced once the treatment is started and the illness transitions to remission. The treatment of GPA consists of an induction phase and maintenance therapy. The most commonly prescribed medications are combinations of glucocorticoids and immunosuppressants. When complications occur, additional treatment may include immunoglobulins, Co-Trimoxazole or plasma transfusion. The majority of treated patients (approximately 90%) achieve remission. The prognosis of the disease is influenced by various factors, especially depending on which organs or organ systems are damaged. Over the last two decades survival among GPA patients has been increasing. However, mortality still remains higher when compared with a healthy population.

Keywords: Granulomatosis with polyangiitis, Wegener’s granulomatosis, ANCA associated vasculitis, diagnosis, treatment.