Table 3.

Characteristics, clinical information, and laboratory findings of patients with coronavirus disease 2019 who underwent kidney biopsy^a

Pt.	Age, yr	Female Sex, n (%)	HTN/DM Present, n (%)	CKD Status, n (%)	Kidney Presentation/Biopsy Indication, n (%)	Peak Serum Creatinine (mg/dl)b	UPCR (mg/g Creatinine)	Dipstick Hematuria	Serology/Laboratory Findings, n (%)	Risk Factors for AKI (Other Than COVID-19), n (%)	Treatment, n (%)	Outcome, n (%)
Necrotizing GN
C1–C3	81 (75–81)	2 (69)	HTN/DM II: 2 (67)	CKD: 1 (33)	AKI with positive ANCA serology: 3 (100)	4.2 (4.1–5.9)	2778 (1915 –3640)	2+ (1+ to 3+)	Positive anti–MPO-ABs: 2 (67) Positive anti–PR3-ABs: 1 (33)	Respiratory failure due to pulmonary-renal syndrome: 1 (33) Acute decompensated heart failure: 1 (33) Sepsis, vasopressor use: 1 (33)	Cs (for vasculitis)+RTx: 1 (33) Cs (for COVID-19 and vasculitis)+CYP: 1 (33) None: 1 (33)	Short-term KRT; ultimately death: 1 (33) Short-term KRT; PKR: 1 (33) PKR: 1 (33)
TMA
C4–C7c	41 (28–50)	3 (75)	HTN: 1 (25)	Stable CKD: 1 (25)	Postpartum AKI, suspected DIC/TMA: 2 (50) AKI with nephrotic syndrome, suspected TMA: 1 (25) AKI on CKD, suspected TMA: 1 (25)	5.0 (3.5–7.6)	8160 (1600 –14,720); N/A in one patient	3+ (2+ to 3+); N/A in one patient	Thrombocytopenia, hemolytic anemia, positive fragmentocytes; no mutations in the complement regulators: 1 (25) Thrombocytopenia, hemolytic anemia: 1 (25) Heterozygous variant c.2792G>A p.(Cys931Tyr) (chr1:g.196709758G>A) in complement factor H: 1 (25) None: 1 (25)	Peripartum hemorrhage with massive blood transfusion and clotting factor replacement; mechanical ventilation: 1 (25) Postpartum sepsis with multiple organ failure including cardiomyopathy, suspected HELLP syndrome/DIC, rhabdomyolysis, mechanical ventilation, vancomycin therapy: 1 (25) None: 2 (50)	Plasmapheresis, eculizumab, Cs for COVID-19: 1 (25) Plasmapheresis, eculizumab, Cs for COVID-19: 1 (25) None: 2 (50)	Maintenance dialysis: 1 (25) Short-term KRT; outpatient eculizumab treatment; CKR: 1 (25) Short-term KRT; PKR: 2 (50)
Podocytopathies
C8–C9	49 (35–62)	1 (50)	HTN/DM II: 1 (50)	CKD: 1 (50)	AKI on CKD: 1 (50) Nephrotic syndrome: 1 (50)	2.8 (0.6–5.1)	7000 and dipstick 3+	2+: 2 (100)	None: 2 (100)	(Patient of African origin): 1 (50) None: 1 (50)	Cs for COVID-19: 1 (50) Cs for minimal change disease: 1 (50)	PKR: 2 (100)
ATI
C10–C14	50 (29–62)	2 (40)	HTN: 4 (80)	Stable CKD (primary FSGS): 1 (20)	AKI on CKD, nephrotic syndrome: 1 (20) AKI, suspected TMA: 1 (20) AKI, NRP: 1 (20) AKI: 2 (40)	11.5 (6.1–14.4)	3551 (2175–22,970)	3+ (1+ to 3+)	Positive circulating immune complexes: 1 (20) None: 4 (80)	Noninvasive ventilation, critical illness: 2 (40) Piperacillin/tazobactam therapy; rhabdomyolysis: 1 (20) Frequent preadmission NSAID use; piperacillin-tazobactam therapy: 1 (20) None: 1 (20)	Cs for COVID-19: 2 (40) None: 3 (60)	Maintenance dialysis: 2 (40) Short-term KRT; PKR: 2 (40) PKR: 1 (20)
IN
C15	32	M	None	Unknown	AKI on suspected CKD	7.7	460	Negative dipstick	None	None	Cs for IN	PKR

Values are median (interquartile range) or n (%). Pt., patient; HTN, hypertension; DM, diabetes mellitus; UPCR, urine protein-to-creatinine ratio; COVID-19, coronavirus disease 2019; DM II, type 2 DM; MPO, myeloperoxidase; ABs, antibodies; PR3, proteinase 3; Cs, corticosteroids; RTx, rituximab; CYP, cyclophosphamide; PKR, partial kidney recovery; TMA, thrombotic microangiopathy; DIC, disseminated intravascular coagulopathy; N/A, not available; HELLP, hemolysis, elevated liver enzymes, and low platelets; CKR, complete kidney recovery; ATI, acute tubular injury; NRP, nephrotic-range proteinuria; NSAID, nonsteroidal anti-inflammatory drug; IN, interstitial nephritis; M, male.

^aDetailed clinical and laboratory data on the investigated cases with COVID-19 are provided in Supplemental Table 5.

^bTo convert the values for serum creatinine to μmol/L, multiply by 88.4.

^cThe information provided on case C7 has been published in part.⁸