2.2 COVID-19 infection and chronic kidney disease

Patients with chronic kidney disease (CKD) are predisposed to COVID-19 (Yang et al., 2020). Emerging reports suggest that patients with pre-existing kidney injuries got worse after testing positive and being admitted to the hospital for COVID-19. In one study, there was an elevation in markers of renal function, elevation of serum D-dimer, pro-inflammatory cytokines particularly interleukin-6 as well as neutrophilia (Yang et al., 2020). It is currently unclear as to the extent the virus directly damages renal tubular epithelial cells or whether the kidney injury is secondary to the cytokine storm syndrome (Cheng et al., 2020; Qian et al., 2020). In a study involving 1,603 patients with COVID-19, 21% presented with increased serum creatinine levels while 43.5% of them had a previously diagnosed CKD stage 3 or higher and with higher mortality rates than in the non-CKD group (Portoles et al., 2020). In these CKD patients (n = 146), urea, serum potassium, urinary proteins, D-dimer, procalcitonin, lactate and troponins levels were elevated while hemoglobin, platelets, albumin and estimated glomerular filtration rate were decreased. Mortality was high in COVID-19 patients with elevated serum creatinine (32.4%) and those with previously diagnosed CKD (41.1%) than those with normal serum creatinine levels (5.8%) (Portoles et al., 2020). In summary, COVID-19 infection appears to damage the kidney and may accelerate the death of patients with CKD.