Acute renal impairment in coronavirus-associated severe acute respiratory syndrome

Abstract

Background: Severe acute respiratory syndrome (SARS) is a newly emerged infection from a novel coronavirus (SARS-CoV). Apart from fever and respiratory complications, acute renal impairment has been observed in some patients with SARS. Herein, we describe the clinical, pathologic, and laboratory features of the acute renal impairment complicating this new viral infection.

Methods: We conducted a retrospective analysis of the plasma creatinine concentration and other clinical parameters of the 536 SARS patients with normal plasma creatinine at first clinical presentation, admitted to two regional hospitals following a major outbreak in Hong Kong in March 2003. Kidney tissues from seven other patients with postmortem examinations were studied by light microscopy and electron microscopy.

Results: Among these 536 patients with SARS, 36 (6.7%) developed acute renal impairment occurring at a median duration of 20 days (range 5-48 days) after the onset of viral infection despite a normal plasma creatinine level at first clinical presentation. The acute renal impairment reflected the different prerenal and renal factors that exerted renal insult occurring in the context of multiorgan failure. Eventually, 33 SARS patients (91.7%) with acute renal impairment died. The mortality rate was significantly higher among patients with SARS and acute renal impairment compared with those with SARS and no renal impairment (91.7% vs. 8.8%) (P < 0.0001). Renal tissues revealed predominantly acute tubular necrosis with no evidence of glomerular pathology. The adjusted relative risk of mortality associated with the development of acute renal impairment was 4.057 (P < 0.001). By multivariate analysis, acute respiratory distress syndrome and age were the most significant independent risk factors predicting the development of acute renal impairment in SARS.

Conclusion: Acute renal impairment is uncommon in SARS but carries a high mortality. The acute renal impairment is likely to be related to multi-organ failure rather than the kidney tropism of the virus. The development of acute renal impairment is an important negative prognostic indicator for survival with SARS.

Figure 1

Serial measurement of plasma creatinine (expressed as median) of these 36 severe acute respiratory syndrome (SARS) patients complicated with acute renal failure (ARF).

Figure 2

Plasma creatinine concentrations. (A) The least squares mean plasma creatinine concentration over time for alive patients (N = 3) and deceased patients (N = 33) deducted from polynomial equations of mixed linear model. (B) The least squares mean plasma creatinine concentration deducted from polynomial equations of mixed linear model for patients who died within 15 days (N = 12), within 15 to 30 days (N = 19), and after 30 days (N = 2). FU is the duration of hospitalization.