Abstract A 45-year-old female with history of atypical hemolytic uremic syndrome (aHUS) treated with ravulizumab, stage 3b CKD, COPD, T1DM, and recent admissions for CAP and DKA presented to an outside ED complaining of left lower extremity pain and swelling. She had associated respiratory symptoms including dyspnea and progressive dry cough and was requiring 4 Lpm of oxygen from a baseline of 2 Lpm. She was found to have a large left DVT, resulting in transfer to our medical center for thrombectomy.Exam revealed 4+ LLE edema and absent left sided breath sounds. Labs were significant for WBC 15.0 k/uL, hemoglobin 7.2 g/dL, Hgb A1c 16.3. CT angiogram of the chest demonstrated a large left-sided pleural effusion with near total collapse of the left lung and pulmonary artery (PA) pseudoaneurysm.A chest tube was placed with frankly purulent output. Vancomycin and zosyn were started empirically. Blood and pleural fluid cultures remained negative through hospital day four, and therefore ID was consulted. Sputum and serum testing for mucor was sent and empiric amphotericin B was initiated. Sputum mucor PCR returned positive and posaconazole and caspofungin were added.The patient underwent a pneumonectomy of a completely consolidated left lung. She subsequently developed severe right ventricular failure, acute renal failure, and progressive neurologic deterioration with absence of brainstem reflexes. The patient’s surrogate decision makers decided to transition to comfort care measures and the patient died shortly after.This immunocompromised patient on terminal complement inhibition, with asplenia and T1DM had angioinvasive pulmonary mucormycosis following a subacute disease course with multiple hospitalizations for pneumonia and DKA. While the patient's uncontrolled diabetes and recent admission for DKA are both known risk factors for mucormycosis, the association between mucor infection and complement inhibition via ravulizumab with asplenia is not well established. Ravulizumab functions as a terminal complement inhibitor by inhibiting cleavage of C5 into C5a and C5b. In vitro studies and murine models suggest that the innate immune response to mucormycosis infection is dependent upon the alternative complement pathway which includes C5a and C5b as central mediators. Furthermore, the spleen contributes to phagocytosis of opsonized pathogens—another important aspect of the alternative complement pathway. Additionally, mucor infection in association with other hypocomplementemic states has been described in previous case reports. It thus seems likely that our patient's treatment with ravulizumab and asplenia put her at significantly increased risk for this rare but devastating infection. This abstract is funded by: None
Kreber et al. (Fri,) studied this question.