From the Guidelines
Respiratory viruses that can cause proteinuria and leukocyturia include influenza viruses, respiratory syncytial virus (RSV), adenovirus, coronavirus (including SARS-CoV-2), and parainfluenza viruses, as these viruses can have systemic effects that impact kidney function, leading to urinary abnormalities 1.
Key Points
- The mechanism behind virus-induced proteinuria and leukocyturia involves direct viral invasion of kidney tissue, immune complex deposition, cytokine-mediated inflammation, and systemic inflammatory response syndrome.
- Influenza infections, for example, can directly infect renal tubular cells, while SARS-CoV-2 can bind to ACE2 receptors in kidney cells, causing local inflammation and damage.
- The resulting kidney inflammation leads to increased glomerular permeability, allowing protein to leak into the urine (proteinuria), while the inflammatory response attracts white blood cells to the urinary tract (leukocyturia).
Relevant Viruses
- Influenza viruses (particularly influenza A) 1
- Respiratory syncytial virus (RSV) 1
- Adenovirus 1
- Coronavirus (including SARS-CoV-2) 1
- Parainfluenza viruses 1
Clinical Implications
- These urinary abnormalities are usually transient and resolve as the viral infection clears, but in severe cases, they may indicate more significant kidney involvement requiring supportive care and close monitoring of renal function.
- Rapid PCR panels should be considered for detection of respiratory viruses in patients with cough and/or shortness of breath that might indicate a viral infection 1.
From the Research
Respiratory Viruses Causing Proteinuria and Leukocyturia
- COVID-19, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been associated with kidney involvement, including acute kidney injury (AKI) and proteinuria 2.
- Influenza A, a respiratory virus, has been detected in a hemodialysis patient with end-stage renal disease (ESRD), presenting with worsening cough, shortness of breath, and diarrhea, and was found to have co-infection with SARS-CoV-2 3.
- Respiratory viruses, including influenza, rhinovirus, parainfluenza, adenovirus, metapneumovirus, respiratory syncytial virus, and coronavirus, have been increasingly detected in critically ill patients and can cause severe pneumonia, including cases of community-acquired pneumonia, hospital-acquired pneumonia, and ventilator-associated pneumonia 4.
- Newly identified and emerging respiratory viruses, such as human Metapneumovirus (hMPV), coronaviruses NL63 (HcoV-NL63) and HKU1 (HcoV-HKU1), human Bocavirus (HBoV), and new enterovirus (HEV), have been detected in acute lower respiratory tract infections (LRTI) in children 5.
- A study found that respiratory viruses, including influenza viruses A and B, adenovirus, respiratory syncytial virus (RSV), and human metapneumovirus (HMPV), were detected in 52.64% of children with acute respiratory infection, with the most common combination of two-virus coinfections being IFVA/AdV, followed by IFVB/AdV 6.
Specific Viruses Associated with Proteinuria and Leukocyturia
- SARS-CoV-2 has been associated with proteinuria, including nephrotic-range proteinuria in patients with COVID-19-associated nephropathy (COVAN) 2.
- Influenza A has been detected in a patient with ESRD and proteinuria, although the exact relationship between influenza A and proteinuria is unclear 3.
- Other respiratory viruses, such as adenovirus and respiratory syncytial virus, have been associated with various renal manifestations, including proteinuria and leukocyturia, although the evidence is limited 4, 5, 6.