What’s in a Name: 9 Kidney Research Terms You Should Know

Posted by: DaVita Clinical Research

The clinical research world has plenty of its own terminology and acronyms, and in the specialty of kidney disease and dialysis studies, there are no shortages of new terms to learn to help talk the talk as you engage with nephrology research sites and physicians.  The terms below are a few of the phrases and concepts that being familiar with will help you out when working in the kidney research space.

CKD (Chronic Kidney Disease) vs ESRD (End-Stage Renal Disease)

Frequently in research, the categorization of CKD vs. ESRD is given to describe if a study protocol or investigational product is meant for CKD (pre-dialysis) patient population, or for patients that have progressed to needing hemodialysis treatment, patients with end-stage renal or kidney disease (ESRD or ESKD). CKD is the condition of having lost some of your kidney function and your kidneys are not filtering blood as they should. A patient can have CKD and have enough kidney function to not yet need dialysis treatment. As a person’s CKD progresses, and their kidneys are no longer filtering the blood and removing waste enough to keep the person healthy, hemodialysis treatment would be needed. Typically, in kidney research studies, distinguishing between a “CKD” or “ESRD” will refer to the patient population the study requires, either with chronic kidney disease (CKD) or a dialysis patient.

PD (peritoneal dialysis), ICHD (in-center hemodialysis), and HHD: (home hemodialysis)

This alphabet soup describes how the different modalities, or ways in which patients with end-stage kidney disease can receive dialysis treatment.

      • ICHD: In-center hemodialysis is when a person goes to a dialysis center for their hemodialysis treatments. Hemodialysis is a treatment that filters the blood of wastes and extra fluid when the kidneys are no longer able to perform this function.
      • PD: PD is a needle-free treatment that you can perform at home during the day or even at night while you sleep by using the lining of the abdomen to filter waste from the blood.
      • HHD works much like in-center hemodialysis but is done at home with a smaller, more user-friendly machine that cleans toxins from your blood.

*For more information about the modalities of dialysis click here.

MWF (Monday, Wednesday Friday) and TTS (Tuesday, Thursday, Saturday)  

Patients that receive in-center hemodialysis do so on different days of the week and shifts. Patients are typically on either a Monday-Wednesday-Friday schedule or Tuesday-Thursday-Saturday. Understanding the patients’ dialysis schedules is crucial to patient visits when considering timing of protocol visits. Within the MWF and TTS schedule, patients will also have shifts (1st, 2nd, 3rd, or perhaps 4th). If research procedures need to happen before or after a dialysis treatment, knowing which shift the patient is on will help understand potential recruitment barriers for the clinical research sites.

GFR, KT/V, TSTAT, PTH and more! 

These abbreviations are some of the common labs and tests that are typical for patients with kidney disease. For patients on dialysis, labs are drawn at least monthly.

  • Serum Creatinine – determines how much creatinine is in the blood. Creatinine is a chemical waste product in the blood that passes through the kidneys to be filtered and eliminated in urine, is in the blood.
  • Glomerular filtration rate (GFR) – This is a calculation that is used to determine how well kidneys are working to remove waste from your blood. It is the best way to check kidney function. This test is a calculation based on your creatinine level, age, gender, and other factors.
  • KT/V – is a calculation that determines how well the dialysis treatment is cleaning your blood
  • TSTAT and ferritin – measure the amount of iron in your body
  • Hb (Hemoglobin) – is drawn to show how much hemoglobin is in the blood
  • PTH – measure the amount of parathyroid hormone

*For more information about understanding your lab work click here.

Routes of administration for drugs and what that means for kidney disease (oral, IV)  

Drugs can be given in different routes. If a patient is treated on hemodialysis it is important to understand how the route of administration can be done in the dialysis center, before, during, or after a dialysis session, intravenous, orally taken, or at home by the patient themselves. There are specific requirements for who can administer or even prepare new drugs for a research study depending on the route, and in which setting the patient is dosed or administered a drug.  When working with research sites in a dialysis setting be prepared to know that non-research personnel may need to prep or administer the study drug.

“The Bundle” 

This means the bundled payment for dialysis services, that are covered by Medicare. Understanding the bundle is important for studies that take place in a dialysis center. Routine or standard of health care procedures that may be part of research visits for dialysis patients are part of the Medicare bundle. It is crucial to have knowledge of this when beginning a clinical trial. As dialysis procedures, tests, labs, and drugs are included in the Medicare bundle, dialysis providers have rules and processes in place for a group of participants to make sure billing to Medicare is correct, and that items are not being double billed.


Dialysis access is what allows the blood to travel to the dialysis machine for hemodialysis. There are different types of vascular accesses for hemodialysis.

      • Fistula (AV Fistula) – connecting the artery and vein, using the patient’s own artery and vein.
      • Graft (AV Graft) – is similar to a fistula, it connects the vein and artery, but with a synthetic tube.
      • Central Venous Catheter (CVC) – is a tube that is placed in a large vein, most commonly in the neck or chest.

For more information click here.

FSGS, Lupus Nephritis, and IGAN  

Two of the most common causes of kidney disease are diabetes and high blood pressure. However, there are other conditions that can cause kidney impairment. DaVita Clinical Research has participating clinical study sites on studies for these and other indications.

  • FSGS is Focal Segmental Glomerulosclerosis is a very rare disease (7 in one million people per year are diagnosed) in which there is scarring on the filters (glomerulus) in your kidneys. 
  • Lupus Nephritis is inflammation of the kidney caused by systemic lupus erythematosus (SLE), also called lupus, an autoimmune disease. If lupus nephritis is not controlled, it can lead to kidney failure.
  • IGAN is IgA nephropathy, which is inflammation in the kidney caused when an antibody called immunoglobulin A (IgA) builds up in your kidneys


HIFs are a buzzword in the dialysis and research industries. Many patients with ESKD have anemia, which is the condition when blood has a lower-than-normal amount of red blood cells or hemoglobin. These patients may be prescribed erythropoiesis-stimulating agents (ESAs) to help increase their red blood cells. Erythropoietin is a hormone in the body that helps produce red blood cells. New compounds are currently being studied and reviewed by the FDA (Food and Drug Administration) to see if they will help patients produce erythropoietin. These are the HIFs, Hypoxia-inducible factors. They work in a different mechanism than current ESAs. This mechanism is similar to the effects of a body at high altitude, being under low oxygen conditions, and producing more of the erythropoietin hormone.