A 60-year-old male from Ecuador who was admitted in August 2020 due to few days of dyspnea, without any other referred symptoms. Upon arrival, he was normotensive and afebrile with basal oxygen saturation greater than 94%, but tachypneic at 16 breaths per minute. SARS-CoV-2 RT-PCR in pharyngeal exudate was positive. Laboratory results revealed usual parameters of COVID infection with a clear renal involvement: Plasma creatinine 3.94 mg/dl, eGFR (CKD-EPI): 16 ml/min/1.73 m2, microhematuria and moderate proteinuria (Table 1 ). Chest X-ray with bilateral interstitial pneumonia (Fig. 1 ). The patient worked as a painter in construction, had no toxic habits or contact with animals, and had long-term hypertension.
Seven years earlier, he had been studied in another center for dyspnea, identifying multiple pulmonary infiltrates and pulmonary thromboembolism. Thrombophilia study was negative. He was on oral anticoagulation for 6 months with acenocoumarol.
Three years ago, again had dyspnea and ventilation-perfusion scintigraphy showed, multiple filling defects compatible with multiple pulmonary thromboembolisms, and oral anticoagulation was reintroduced.
Seven months earlier, he returned to hospital after presenting a cough of several months' duration with purulent expectoration, self-limited hemoptysis, and thoracic pain. Chest X-ray and chest computed tomography revealed multiple consolidative opacities in the SLL, ML, and upper segment of the RIL with bilateral peri bronchial-vascular inflammatory nodules, one of them cavitated in the left apex. With suspicion of active post-primary tuberculosis, he was discharged and scheduled for additional complementary evaluations but the patients did not return.
Five months before, he came to our center for the first time due to chest pain with dyspnea. Signs of diffuse interstitial lung disease were identified, along with new pulmonary infarcts. The patient also had antiphospholipid syndrome, livedo reticularis, and positivity for p-ANCA (anti-MPO) and anticentromere antibodies. Paresthesia of the lower limbs, pericardial effusion, and mural thickening of the aorta and supra-aortic trunks (aortitis) compatible with vasculitis of the aortic arch and supra-aortic trunk. CT/PET without signs of activity. At that time, a moderate renal involvement is already detected.
Pulmonary artery stenosis and new bilateral pulmonary infiltrates are also observed, in addition to the previously known cavitated one. He was discharged on treatment with colchicine, isoniazid, rifampicin, pyrazinamide, and ethambutol, which he maintained for 3 months, until receiving negative results for BAAR, PCR for Mycobacterium tuberculosis, and IGRA (QuantiFERON-TB Gold In-Tube ).
Upon admission, he began treatment with levofloxacin, prophylactic anticoagulation with LMWH, and respiratory support. Both renal insufficiency and respiratory failure worsen. Thus a renal biopsy was performed 10 days after admission, with a clinical judgment of pauci-immune mixed extracapillary proliferative glomerulonephritis associated with ANCA with moderate chronic changes (Fig. 2 ).
At the same time, he developed multifactorial parenchymal liver disease (quinolone, viral hepatotoxicity and hepatic vasculitis), so levofloxacin was replaced by ceftriaxone. On day 11, he developed anemia that required blood transfusion without data of post-biopsy renal bleeding by ultrasound; the patient also had self-limited hemoptysis with a fiberoptic bronchoscopy without findings, for which he received 3 doses of 500 mg of methylprednisolone. He evolved poorly, with radiological progression of the infiltrates, greater respiratory and renal failure, so on day 16 we started IV immunoglobulins at a dose of 0.2 mg/kg/day for 5 days and on day 19, after recovering liver function, he received 2 doses tocilizumab, 600 mg on the first day and 400 mg on the second day. He was admitted to the ICU and treated with continuous veno-venous hemodiafiltration (VVCHDF) (3 sessions) and respiratory support with high-flow NIV. Glomerular filtration recovered slowly and respiratory function improved with a better oxygenation. After verifying positive COVID IgG serology on day 21, treatment with rituximab was scheduled, 4 doses of 375 mg/m2/week IV. It was proposed to complement the treatment with a new batch of immunoglobulins, but it was not held since levels in plasma were maintained adequately. Renal function stabilized with GFR 20-30 m/min/1.73 m2, but respiratory infiltrates and ventilatory dependency did not improve during the following 3 weeks despite physical therapy and adequate support. Due to this torpid respiratory evolution, fiberoptic bronchoscopy was repeated without relevant findings. Finally, he could be discharged after 50 days of hospitalization with chronic home oxygen and an eGFR 27 ml/min.