Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.
Inclusion Criteria:
Diagnosis of diabetes mellitus (type 1 or 2) established by at least one of the following criteria:
Hemoglobin A1C greater than or equal to 6.5%, confirmed with a repeat test within the past year o Fasting blood sugar greater than or equal to 126 mg/dL, confirmed with a repeat test within the past year.
Use of glucose-lowering therapy (insulin or oral or other subcutaneous agents)
International Classification of Diseases (ICD) 9/10 diagnostic code for diabetes.
Evidence of persistent kidney damage, manifest as any of the following present on at least two clinic assessments prior to enrollment and at least 3 months apart and excluding people with acute medical illnesses and changing kidney function:
Estimated glomerular filtration rate 30-59 mL/min/1.73m2
Estimated glomerular filtration rate greater than or equal to 30 mL/min/1.73m2 with urine albumin excretion greater than or equal to 30 mg/g creatinine (or mg/day)
Estimated glomerular filtration rate greater than or equal to 30 mL/min/1.73m2 with urine protein excretion greater than or equal to 150 mg/g creatinine (or mg/day)
Most recent eGFR must be within the past year and be ≥30 mL/min/1.73m2 .
Diagnosis of hypertension (HTN) established by at least one of the following criteria:
BP greater than 140/90 mmHg measured on three occasions over at least 1 month
Taking antihypertensive medication for blood pressure (BP) control
International Classification of Diseases (ICD) 9/10 diagnostic code for hypertension
Evidence of persistent kidney damage, manifested as any of the following present on at least two assessments at least 3 months apart and excluding people with acute medical illnesses and changing kidney function:
Estimated glomerular filtration rate 30-59 mL/min/1.73m2 on two assessments at least 3 months apart with albuminuria less than or equal to 2000 mg/g creatinine (or mg/day), or proteinuria less than or equal to 3000 mg/g creatinine (or mg/day), or ≤1+ proteinuria on urinalysis, or
Estimated glomerular filtration rate greater than or equal to 30 mL/min/1.73m2 with urine albumin excretion 30-2000 mg/g creatinine (or mg/day) or
Estimated glomerular filtration rate greater than or equal to 30 mL/min/1.73m2 with urine protein excretion 150-3000 mg/g creatinine (or mg/day)
Most recent eGFR must be within the past year and be ≥30 mL/min/1.73m2 .
Baseline estimated glomerular filtration rate greater than 45 mL/min/1.73m2. Baseline defined by the median of the last three outpatient serum creatinine measurements from day 7 to 365 prior to enrollment.
If only two measurements are obtained within this window, the two results will be averaged.
If only one measurement was obtained within this window, this result will be used
If baseline is missing, the potential participant can be enrolled with an estimated baseline, but only if there is no past medical history of chronic kidney disease.
If the AKI RS PI believes that the baseline serum creatinine under or over-estimates baseline, a unanimous vote of AKI site PIs can confirm eligibility based on a review of deidentified serum creatinine values provided by the site PI.
AND ONE of the following criteria must be met:
Drop in urine output (<500 ml/24 hours)
Any rise in serum creatinine ≥0.3 mg/dl over the baseline serum creatinine
A rise in serum creatinine >0.1 mg/dl in a patient with high risk of AKI and at least one of the following:
Positive kidney injury urine biomarker, as defined by any of the following:
NGAL level greater than or equal to 150 ng/mL by ELISA or clinical analyzer
KIM1 level greater than or equal to 2.8 ng/mL by ELISA
TIMP2 x IGFBP7 greater than or equal to 2.0 by NephroCheck®
Urine microscopy suggestive of acute tubular necrosis defined as a urine microscopy score of greater than or equal to 2.
greater than or equal to 1 Renal Tubular Epithelial cells (RTE) per high powered field (HPF) AND greater than or equal to 1 granular cast/ low powered field (LPF); or
greater than or equal to 5 Renal Tubular Epithelial cells (RTE) per high powered field (HPF); or
greater than or equal to 5 granular cast/ low powered field (LPF)
A special population of people with long-standing type 1 diabetes (>25 years) who remain free of clinically-evident DKD (i.e. DKD “resilient” or “DM-R” individuals) will also be included. Study of the DKD resilient population using KPMP protocols offers a unique opportunity to identify protective factors against complications of diabetes mellitus. Diabetic Kidney Disease Resilient individuals are defined as individuals with diabetes for more than 25 years that are free from clinical nephropathy
Type 1 diabetes for over 25 years
Estimated glomerular filtration rate greater than or equal to 60 mL/min/1.73m2
Urine albumin excretion less than 30 mg/d (or mg/g creatinine)
Closed Special Population: Potential participants undergoing open laparotomy for a clinical indication and who are at high risk for acute kidney injury inclusion criteria
Baseline estimated glomerular filtration rate greater than 45 mL/min/1.73m2 as defined above AND one of the following:
Elevated serum creatinine (greater than 1.5 times baseline) or an increase in serum creatinine greater than or equal to 0.3 mg/dL within 48 hours, above admission serum creatinine.
High risk for acute kidney injury defined by TWO or more criteria:
Positive kidney injury urine biomarker measured at the Recruitment Site, as defined by any of the following:
NGAL level greater than or equal to 150 ng/mL by ELISA or clinical analyzer
KIM1 level greater than or equal to 2.8 ng/mL by ELISA
TIMP2 x IGFBP7 greater than or equal to 2.0 by NephroCheck
Urine microscopy suggestive of acute tubular necrosis:
Greater than or equal to 1 Renal Tubular Epithelial cells (RTE) per high powered field (HPF) AND greater than or equal to 1 granular cast per low powered field (LPF); or
Greater than or equal to 5 Renal Tubular Epithelial cells (RTE) per high powered field (HPF); or
Greater than or equal to 5 granular cast/low powered field (LPF)
Oliguria (less than 0.3mL/kg/hr) at least 1 hour after fluid resuscitation.
One or more exposure(s) known to cause acute kidney injury (major surgery not including index laparotomy, sepsis, nephrotoxic drugs, etc.).
This is the only population previously approved to consent with a legally authorized representative (LAR).
In response to the COVID-19 pandemic, the KPMP temporarily added a flexible and modular COVID-19 substudy to address the critical need to understand the presentation of COVID-19 infection associated kidney complications, with the goal of improving diagnostics, therapeutics, and overall care. Participants from this substudy were asked to consider enrolling in the full KPMP (including kidney biopsy and follow-up visits for up to 10 years) at a baseline KPMP visit approximately three months after their COVID-19 Substudy visit. Inclusion Criteria for COVID-19 Substudy are patients greater than 18 years of age admitted to participating hospitals with a positive COVID-19 test result or Persons Under Investigation with suspected COVID-19 infection AND with AKI or at high risk of AKI in the setting of COVID-19 infection, as defined by any ONE of the following:
pre-existing chronic kidney disease as defined by eGFR less than 60 ml/min/1.73 m2
history of diabetes mellitus
requiring use of vasopressors
requiring use of mechanical ventilation
AKI is defined by temporal changes in serum creatinine meeting KDIGO Stage 1 criteria or greater. If a baseline serum creatinine is not available, the patient can be enrolled with an estimated Baseline serum creatinine (see KPMP COVID-19 Manual of Procedures for details). For a participant to be considered enrolled in the COVID-19 Substudy the consent form must be signed and one or more participant procedures performed from the baseline module. Recruitment for the COVID substudy ended in April 2022.
Exclusion Criteria:
Under 18 years of age
Severe allergy to iodinated contrast
Pregnancy
Transplant recipient (includes solid transplant and bone marrow)
Additional vulnerable individuals (incarcerated, institutionalized, or otherwise unable to participate in the study)
Inability to provide informed consent
Clinical diagnosis of kidney disease from an autoimmune disease, dysproteinemia, viral disease or glomerular disease other than DKD or H-CKD
Unwilling to receive blood transfusion (if needed)
Potential participants will be excluded if the risk of kidney biopsy is considered too high by either the clinicians caring for the potential participant or the investigators at the RS. Note: Participants recruited under the Clinical AKI Biopsy Cohort (section 4.1.3.2) will adhere to safety criteria determined by the treating clinician; KPMP safety exclusion criteria do not apply for this population.
Kidney depth more than 13 cm (percutaneous biopsies only)
Kidney size less than 8 cm (percutaneous biopsies only)
Solitary or single functioning kidney
Evidence of urinary tract obstruction or hydronephrosis
Multiple bilateral kidney cysts that will interfere with the safe performance of the biopsy
Kidney infection, peri-renal infection, or cutaneous infection that overlies the kidney (percutaneous biopsies only)
Any other imaging abnormality, which in the judgement of the operator, prevents biopsy being performed safely.
nternational Normalized Ratios (INR) greater than 1.4
Platelet count less than 100,000/uL
Hemoglobin less than 8.5 g/dL
Chronic anticoagulation
Inability to withdraw aspirin, clopidogrel, cilostazol, or similar anti-platelet agents for at least 7 days prior to biopsy (unless bleeding time is normal before open surgical biopsy); clinical judgement will be used in the case of nonsteroidal anti-inflammatory drugs (NSAID) exposure occurring less than 7 days before percutaneous biopsy.
Blood pressure of more than 160 mmHg systolic or 100 mmHg diastolic.
Ventilator-dependent patient (does not apply to open biopsies)
Hypotension or pressor support requirement (does not apply to open biopsies)
Any other condition where in the judgement of the operator, biopsy cannot be performed safely.
Note: Other protocol defined Inclusion/Exclusion Criteria may apply.
Eligibility last updated 7/10/2025. Questions regarding updates should be directed to the study team contact.