Microscopic polyangiitis

Case contributed by Dr Yesid Cardozo Vélez


Presented to the emergency department, reporting dyspnea, edema of the lower limbs, asthenia, and adynamia. At the physical examination, he was obtunded and had bibasal rales. On laboratory tests, acute chronic renal failure and anemic syndrome of normal volumes were demonstrated. On arterial gases, hypoxemia (pO2: 65 mm Hg) and hypocapnia (pCO2: 29 mm Hg) was found. On an endoscopic study of the digestive tract, no lesion was found that will explain the anemic syndrome. An echocardiogram T.T. reported mild concentric LV hypertrophy with normal systolic function: 60%.

Patient Data

Age: 70 years
Gender: Female

Air space opacification with a tendency to bilateral consolidation and random distribution. In some areas, opacities in ground glass are observed. Obliteration of right cardiogenic and costophrenic angles due to pleural effusion


Areas of consolidation and ground glass of random distribution, with thickening of septa and bilateral pleural effusion.

Pulses of methylprednisolone are started and resolves the respiratory failure with cessation of the NIMV. Start of immunosuppressive treatment with cyclophosphamide, achieving
stabilization of renal function.


A chest x-ray is taken 10 days after the initiation of immunosuppressive treatment in which almost complete resolution of the consolidations is observed.

Case Discussion

An alveolar pattern of random distribution, in the context of a patient with acute renal failure, requires to consider as a first diagnostic possibility pulmonary-renal syndrome: which in turn includes the following differential diagnoses:

  • Goodpasture disease
  • systemic lupus erythematosus
  • ANCA-associated vasculitis

Based on the described findings, studies aimed at the proposed differentials show strong positivity for p-ANCAs (1/320) with a c-ANCA negative. This immunological pattern, in the appropriate clinical context, is a diagnosis of microscopic polyangiitis. Immunosuppressive treatment is started with good clinical response. The patient was discharged in good general condition with outpatient rheumatology follow-up. 

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Case information

rID: 64982
Published: 19th Dec 2018
Last edited: 14th Aug 2019
System: Chest
Inclusion in quiz mode: Included
Institution: Universidad Tecnológica de Pereira

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