From Fibrosis to Diagnosis

Background: Microscopic polyangitis is a rare autoimmune disease characterized by necrotizing inflammation of small-size vessel walls.

Case report: We herein present a case of 6-year-old girl whose way to establishing a proper diagnosis may be summed up by the phrase “from fibrosis to diagnosis”. The history of our patient starts in the Department of Pulmonology where she was refered by her GP due to persistent crepitations at the base of both lungs, resistant to the antibiotic treatment. A CT scan performed there revealed that those auscultation changes were not the result of, as primarily thought, infective process but manifestations of massive lung fibrosis. What is more, at that time another symptom appeared – haematuria. In the search of a cause of lung fibrosis with an early onset in the differential diagnosis many pulmonary diseases were excluded (cystic fibrosis, Goodpasture syndrome, α-1 antitrypsin deficiency, congenital abnormalities of surfactant homeostasis). Due to the presence of antinuclear antibodies in the patients serum the girl was transferred to Department of Rheumatology with suspicion of systemic inflammatory connective tissue disease. In the laboratory tests performed there presence of antinuclear antibodies was not confirmed, but what draw attention was existence of p-ANCA antibodies in high titer. What is more, haematuria with the tendency to increase was also noted. Due to the complicated overall clinical picture and ambiguous laboratory tests results the biopsy of the lung and kidney tissue was performed, which shoved features of microscopic polyangitis in the former and glomerulonephritis in the latter. Finally, the diagnosis of microscopic polyangitis was established and glucocorticosteroids and cyclophosphamide pulses were introduced into the treatment with good clinical response.

Conclusion: Due to the fact that microscopic polyangitis is a very rare disease in children and can affect almost every organ of the human body the diagnostic and therapeutic process of this disorder is challenging and usually requires a multidisciplinary approach.