Table 1. Primary and Secondary Criteria for Individual Phenotypes.

Phenotype	Acute kidney Injury	Glomerular Disorder	Nephrolithiasis	Tubular Dysfunction
Characteristics	ATN1 AIN Osmotic nephrosis	hematuria, proteinuria	Crystalluria Nephrolithiasis Ultrasound findings of stone with or without obstruction	Renal tubular acidosis Fanconi syndrome SIADH2 Diabetes Insipidus Phosphate wasting
Primary Criteria	Rise in Scr that presents as or progresses to Stage 2 (KDIGO) 2-2.9 × reference Scr or higher If child has baseline Scr < 0.5 mg/dL, must double Scr to get to at least 0.5 mg/dL or above OR Decline by at least 50% from peak Scr over 7 days in relationship to change in drug dosing adjustment or discontinuation within 2 weeks	Biopsy proven drug induced glomerular disease (within 4 weeks of stopping drug) AND Proteinuria as defined by: 24 hr collection > 1 gram protein UPC or UACR > 0.8 Urinalysis 2+ protein100-300 mg/dL albumin Children: 100 mg/m2/day or 4 mg/m2/hr Hematuria > 50 rbc/HPF	Must be new onset following drug exposure with no prior history of nephrolithiasis No evidence of congenital etiology for nephrolithiasis If obstructive, rise in Scr that presents as or progresses to Stage 2 (KDIGO) or higher If non obstructive, then: Urinalysis with crystals Ultrasound with stone	Tubular: Hypophosphatemia OR Glucosuria Urinalysis with 3+ glucose without diabetes OR Hyperchloremi c metabolic acidosis AND Hypokalemia or hyperkalemia Diabetes insipidus: Hypernatremia > 155 mEq/L on multiple occasions Polyuria > 3L/day
Secondary criteria	Oliguric <500ml/day or <0.5ml/kg/hr for12 hrs (KDIGO Stage2) Non-oliguric >500 ml/day, >1mL/kg/hr for 24 hours (pediatrics) Urinalysis findings: granular and muddy casts consistent with ATN, urinary eosinophils, proteinuria FeNa > 1% Negative ultrasound findings Positive gallium scan for AIN Clinical symptoms for AIN: fever, rash, joint pains	Culture negative leukocyturia > 50 wbc/HPF Casts RBC; Granular, Absence of secondary disorder that can cause GN: DM, lupus, post infectious, hepatitis etc. Microangiopathic changes in blood Smear, LDH; haptoglobin Nephritic, nephrotic, mixed	Urine electrolytes Stone work up	Phosphaturia FePO4 > 5% Urinary PO4 excretion > 100 mg/day Hypomagnesemia serum magnesium < 1.2 mg/dL Hypouricemia Serum uric acid < 2 mg/dL Tubular Proteinuria 24 hr collection < 1 gram protein UPC < 0.8 Urinalysis < 2+ protein Diabetes insipidus Serum osmolality > 300 mosm/kg Urine osmolality < 100mOsm/kg Urine sodium < 10 mEq/L

¹Hemodynamic changes may contribute to ATN, however, in the absence of any specific features are not considered individual criteria for the AKI phenotype.

²SIADH does not reflect direct tubular damage but rather the impact of a drug on ADH secretion and subsequent impaired water handling.

AIN = acute interstitial nephritis, ATN = acute tubular necrosis, DM = diabetes mellitus, FeNa= fractional excretion of sodium, FePO4 = fractional excretion of phosphorus, GN = glomerulonephritis, HPF = high powered field, LDH = lactate dehydrogenase, RBC= red blood cell, SIADH= syndrome of inappropriate antidiuretic hormone, UPC = urine protein to creatinine ratio, UACR= urine albumin to creatinine ratio, WBC = white blood cell.