Renal disease: renal Flashcards
How does renal disease often present?
Renal disease can present as an incidental finding, symptomatic condition, or as a result of being associated with a systemic disorder.
Name some systemic disorders associated with renal disease.
Renal disease can be associated with systemic lupus erythematosus (SLE), sarcoidosis, myeloma, and certain inherited diseases.
What are some indicators of incidental renal disease?
Abnormal renal function tests, urinary abnormalities, hypertension, or the presence of a small or dilated kidney on imaging can indicate incidental renal disease.
Why is renal disease often asymptomatic?
Renal disease is often asymptomatic because there can be large changes in the glomerular filtration rate (GFR) without a significant increase in creatinine levels, especially in the early stages. Additionally, kidneys have significant excess capacity, with GFR needing to drop below 50% before creatinine levels rise above the normal range. Symptoms related to reduced kidney function are typically uncommon until GFR drops below 15.
What are some commonly measured blood tests used to assess renal function?
Commonly measured blood tests used to assess renal function include sodium, potassium, urea, creatinine, bicarbonate, arterial blood gases (pH), and lactate levels.
What is hyperkalemia?
Hyperkalemia refers to the elevated levels of potassium in the blood, which can be indicative of renal dysfunction.
What are some urinary abnormalities that can be detected through urinalysis?
Urinalysis can detect non-visible blood, protein, glucose, ketones, bilirubin, pH, nitrites, and leucocytes in the urine.
What is proteinuria, and how is it detected?
Proteinuria refers to the presence of protein in the urine. It can be detected using a dipstick test to see a list of proteins. Up to 200 mg of protein in a 24-hour urine collection is usually insignificant. Different types of renal pathology are associated with different protein loss.
How can proteinuria be measured without a 24-hour urine collection?
Proteinuria can be measured using the protein/creatinine ratio (PCR) or the albumin/creatinine ratio (ACR). The PCR/ACR (mg/mmol) multiplied by 10 is approximately equal to the 24-hour excretion of protein in milligrams (mg/24 hrs).
Why is proteinuria screening important for general practitioners (GPs)?
GPs are increasingly required to screen for proteinuria in patients with conditions such as diabetes, chronic kidney disease (CKD), and cardiovascular risk. Screening for proteinuria helps in assessing kidney function and determining appropriate management strategies.
What are the benefits of using the albumin/creatinine ratio (ACR) for proteinuria testing?
Albumin testing using the ACR has become the standard assay for proteinuria. It provides a more accurate assessment of albumin excretion and is particularly useful in detecting early stages of kidney damage.
How does proteinuria impact chronic kidney disease (CKD) progression?
Proteinuria increases the risk of CKD progression. Protein itself can be nephrotoxic to the tubules, further contributing to kidney damage. If proteinuria is present, more aggressive targets are often set for the treatment of blood pressure to help slow down the progression of CKD.
How does increased proteinuria affect renal function?
Increased proteinuria is associated with a faster decline in renal function. Higher levels of protein in the urine indicate greater kidney damage and can be indicative of worsening renal disease.
How can non-visible haematuria be differentiated using urine tests?
Non-visible haematuria can be evaluated using urine microscopy to identify red cell casts. The presence of red cell casts indicates glomerular disease. Alternatively, bleeding from the lower renal tract, such as the renal pelvis downwards, can be caused by conditions like tumors, stones, or even bladder catheterization.
How does renal disease often present?
Renal disease can present as an incidental finding, meaning it is discovered unexpectedly or manifests with symptoms. Additionally, renal disease can be associated with systemic disorders or inherited diseases that are detected through screening processes.
What are some symptoms of symptomatic renal disease?
Symptoms of symptomatic renal disease can include general malaise, “uraemia” symptoms (fatigue, lethargy, confusion, anorexia, nausea, sense of smell and taste changes), nephrotic syndrome (characterized by proteinuria, edema, and hypoalbuminemia), nephritic syndrome (characterized by hematuria, hypertension, and renal impairment), acute kidney injury (acute renal failure), chronic kidney disease, visible hematuria, urinary symptoms (such as increased frequency and dysuria), and pain.
What are some symptoms and signs of uremia?
Symptoms of uremia can include fatigue, lethargy, confusion, anorexia, nausea, sense of smell and taste changes, cramps, restless legs, insomnia, and itching. Signs of uremia can include amenorrhea, hiccups, reduced body temperature, weight loss, pericarditis, pleurisy, seizures, and encephalopathy.
What are some signs of renal disease?
Signs of renal disease can include peripheral edema (swelling in the extremities), purpura (small purple spots on the skin caused by bleeding), muddy brown urine, foamy urine (resembling cola), and periorbital edema (swelling around the eyes).
What are some causes of renal disease?
Some causes of renal disease include pre-renal acute kidney injury (hypovolemia, cardiac failure, hepatorenal syndrome), renal artery occlusion, large/medium vessel vasculitis, small vessel disease (thrombotic microangiopathy, renal atheroembolism, small vessel vasculitis), glomerular disease (anti-GBM disease, lupus nephritis, postinfectious glomerulonephritis, infective endocarditis, membranoproliferative glomerulonephritis, cryoglobulinemia, IgA nephropathy/Henoch-Schönlein purpura), acute tubular injury/necrosis (caused by drugs, aminoglycosides, antiretrovirals, cisplatin, acetaminophen, radiocontrast agents, organic solvents, IV immunoglobulin), acute interstitial nephritis (caused by drugs, infections, systemic diseases), intra-tubular obstruction (cast nephropathy, drugs, crystalluria), and post-renal obstruction (papillary necrosis, tumors, retroperitoneal fibrosis, renal calculi, urinary retention).
What are the key features of the normal glomerulus structure?
The key features of the normal glomerulus structure include capillaries with fenestrated epithelium, a basement membrane, a single layer of epithelial cells called podocytes, foot processes of podocytes, and supporting mesangial cells.
What can cause injury to podocytes?
Podocyte injury can be caused by various factors, including cytokines (e.g., minimal change disease), increased pressure (e.g., hypertensive glomerulopathy), and immunoglobulin deposition (e.g., IgA nephropathy).
What are the patterns and causes of glomerular disease?
The patterns and causes of glomerular disease can vary. The diagnosis of kidney disease is often made based on clinical presentation, but a renal biopsy can provide an accurate diagnosis. Patterns of disease can be observed on light microscopy, electron microscopy, and immunofluorescence for antibodies.
How are diseases of the glomerulus diagnosed?
Diseases of the glomerulus are often diagnosed clinically based on specific symptoms and medical history. However, a renal biopsy is often necessary to provide an accurate diagnosis. Light microscopy, electron microscopy, and immunofluorescence for antibodies are used to identify patterns and specific features of glomerular diseases.
What is glomerulonephritis?
Description: Glomerulonephritis refers to inflammation in the glomerulus, which is the filtering unit of the kidney.
What is the difference between focal and diffuse glomerulonephritis?
Description: Focal glomerulonephritis involves less than 50% of the glomeruli on light microscopy, while diffuse kidney filtering unitre than 50% of the glomeruli.
What is segmental glomerulonephritis?
Description: Segmental glomerulonephritis refers to inflammation that involves only a part of the glomerular tuft, usually in a focal manner.
What is membranous glomerulonephritis?
Description: Membranous glomerulonephritis is characterized by thickening of the glomerular capillary wall, often with distinctive basement membrane “spikes.” It does not involve inflammation.
What are proliferative changes in the glomeruli?
Description: Proliferative glomerulonephritis refers to an increased number of cells in the glomerulus, which can be either proliferating glomerular cells or infiltrating circulating inflammatory cells.
What are some examples of glomerulonephritis?
Description: Examples of glomerulonephritis include minimal change disease, membranous glomerulonephritis, and focal proliferative glomerulonephritis. Each has distinct histological findings and characteristics.
What is Type 1 immune disease of the glomerulus?
Description: Type 1 immune disease involves immediate hypersensitivity reactions mediated by IgE. However, there is no known renal disease associated with this type of immune response.
What is Type 2 immune disease of the glomerulus?
Description: Type 2 immune disease is characterized by antibody-mediated tissue injury. It involves the binding of IgG and IgM antibodies to target cells or matrix components, leading to complement activation and tissue injury at the site. Examples of Type 2 immune diseases of the glomerulus include membranous glomerulonephritis, anti-GBM disease, ANCA-associated glomerulonephritis/polyangiitis, and antibody-mediated graft rejection.
What is Type 3 immune disease of the glomerulus?
Description: Type 3 immune disease involves the formation of immune complexes in the circulation, which deposit within the glomerulus and cause tissue injury by recruiting immune mediators. Examples of Type 3 immune diseases of the glomerulus include lupus nephritis, post-infectious glomerulonephritis, glomerulonephritis associated with hepatitis B or C, and cryoglobulinemic glomerulonephritis.
