1.What are the manifestations of kidney disease? How can I know if I have kidney disease?
The kidney is located on both sides of the spine at the waist and is an important organ of the human body. Its main function is to produce urine, excrete metabolic waste, maintain the body’s water, electrolytes, acid-base balance and the stability of the internal environment; the kidney also produces erythropoietin, activates vitamin D3, promotes bone marrow red blood cell production, regulates calcium and phosphorus absorption, excretion and bone metabolism. According to Chinese medicine, the kidney is the root of the innate nature, and the kidney collects essence, water, energy, bones and marrow, and opens the ears and the two yin, with its flower in the hair. Of course, the concept of “kidney” in Chinese medicine is richer than the concept of “kidney” in Western medicine.
When the kidneys are diseased, the first manifestation is abnormal urine, such as no urine, little urine, polyuria and other quantitative abnormalities, low specific gravity urine, hematuria, protein urine, diabetes, amino acid urine and other qualitative abnormalities, frequent urination, increased nocturia and other frequency abnormalities. Impaired kidney function may manifest as water, electrolyte and acid-base balance imbalance (edema, hypertension, hypokalemia or hyperkalemia, hypocalcemia or hyperphosphatemia, metabolic acidosis, etc.), metabolic waste accumulation (increased blood urea nitrogen, creatinine, uric acid); severe patients may develop anemia and nephrogenic bone disease.
Therefore, when people experience an increase or decrease in the volume or frequency of urine, a reddening, whitening or cloudiness of urine or an increase in urine foam, and an increase in nocturia, they should go to the hospital to check whether they have kidney disease. If facial or lower limb edema and high blood pressure appear, more attention should be paid to the presence of kidney disease. If you have unexplained anemia, lumbar pain, weakness and weakness of the back and knees, you should also check for the presence of kidney disease.
Since many kidney diseases do not show any discomfort in the early stage and can only be detected by health check-ups, it is recommended that people should have a regular health check-up every year, including at least urine routine, blood urea nitrogen, creatinine, uric acid and kidney ultrasound. Especially individuals with hypertension, diabetes and family history of kidney disease and individuals born prematurely and with low birth weight, which are high-risk groups prone to kidney disease, should have regular health checkups.
2. What is the difference between acute and chronic kidney disease?
Once you consider having kidney disease, the first question that needs to be answered is whether it is acute or chronic, which is very important. Because acute, whether it is acute nephritis, acute renal failure or acute urinary tract infection, in most cases, the condition can be reversed and restored to normal with proper treatment; while chronic nephritis, chronic renal failure and chronic complicated urinary tract infection (such as the presence of foreign bodies such as malformations or stents in the urinary tract, chronic pyelonephritis, etc.) are more difficult to treat and difficult to cure completely.
The differentiation between acute and chronic kidney disease relies on medical history and ancillary tests. In terms of time, acute usually refers to a disease duration of less than 3 months, while those lasting more than 3 months to 6 months are usually chronic. Nephrolithiasis usually has only one acute episode, and a reoccurrence is generally considered an acute attack of chronic nephritis, or it can be an acute exacerbation of the underlying chronic kidney disease. Therefore, any child or young adult who has had acute nephritis and reappears as an adult with nephritis manifestations is considered to have chronic nephritis. Renal failure and urinary tract infections can occur multiple times with acute renal failure and acute urinary tract infections; as long as they occur once and then again after being cured, they can be considered acute. If one acute onset, which lasts for 3 months is not cured or not well enough, it is considered as chronic renal failure and chronic urinary tract infection.
In addition to the course and history of the disease, some manifestations and auxiliary tests are also important indicators to distinguish acute and chronic kidney disease. If one month or so ago had a cold or an infection somewhere in the body, and then suddenly appear facial swelling, hypertension, hematuria, proteinuria, increased serum anti-“O”, accelerated sedimentation, decreased complement C3, and large kidney volume, it suggests the possibility of acute nephritis syndrome, especially in adolescents should pay attention. If you have carnal hematuria within 1-2 days after a cold or even on the day of the cold, it is often not acute nephritis, but mostly an acute attack of chronic nephritis (such as IgA nephropathy attack carnal hematuria). If a married woman, after intercourse or exertion, develops frequent urination, urinary urgency, painful urination, and carnal hematuria, and if the urine red blood cells and white blood cells are increased, it suggests an acute urinary tract infection. If there is increased nocturia, anemia, hypocalcemia and hyperphosphatemia and secondary hyperparathyroidism (increased iPTH), and reduced kidney volume, it is usually chronic kidney disease or chronic renal insufficiency.
3. What is the difference between glomerular disease and tubulointerstitial disease?
The manifestations of kidney diseases are all closely related to their physiological functions. Glomerular function is mainly filtration and barrier function, therefore, common glomerular diseases, such as nephritis syndrome and nephrotic syndrome, are mainly reflected in filtration and barrier dysfunction, manifested by abnormal red blood cell urine, different degrees of proteinuria (including albumin-based selective proteinuria, non-selective proteinuria where large molecular weight proteinuria and small molecular weight proteinuria exist simultaneously), decreased glomerular filtration rate edema, hypertension, nitrogen retention, etc.
Therefore, tubular interstitial lesions, such as acute and chronic tubular interstitial nephritis, most drug-related kidney damage, heavy metal poisoning, adult dominant hereditary polycystic kidney disease, renal medullary cystic disease, sponge kidney, and various congenital tubular diseases, mainly manifest as small molecule proteinuria (urinary lysozyme, NAG, β2 microglobulin It is often accompanied by low urine specific gravity or urine osmolality, nephrogenic diabetes, amino acid urine, increased nocturia and hypokalemia due to too much urinary potassium excretion.
4.Differentiation between primary and secondary kidney disease?
Whether it is nephritis or nephropathy or tubulointerstitial disease, they are divided into two categories: primary and secondary. The so-called primary nephritis or primary nephropathy is a glomerular disease of unknown cause so far, often associated with immune abnormalities. Secondary nephritis or secondary nephropathy is nephritis or nephropathy due to other well-defined causes, such as hepatitis B-associated nephritis, which is glomerulonephritis due to hepatitis B virus infection of the kidney; diabetic glomerulopathy, which is glomerulopathy due to diabetes; and hypertensive kidney damage, which is kidney damage due to hypertension.
Primary disease is usually an exclusionary diagnosis, and primary disease can be diagnosed only after secondary disease is excluded. For example, the clinical diagnosis of primary glomerulonephritis must have 2 conditions; there are clinical manifestations of glomerulonephritis, such as hematuria and proteinuria; second, secondary glomerulonephritis must be excluded, such as hepatitis B-associated nephritis, allergic purpura nephritis, lupus nephritis, etc. There are many pathological types of primary glomerulonephritis, and the treatment and prognosis of different pathological types of nephritis are different. Although the possible pathological diagnosis can be speculated based on the clinical manifestations, a kidney tissue aspiration biopsy is required to clarify its pathological diagnosis. Glomerular disease can be considered if a patient has a definite aberrant erythrocyte increase (>3 per high-powered field of view) on urine examination in a quiet state, combined with overt proteinuria (urine protein quantification >0.5g/24h), excluding tubulointerstitial disease, and glomerular disease is more likely if combined with facial or lower extremity edema and hypertension. If you want to clarify the type of pathology, renal biopsy pathology examination is recommended. The common pathological types of primary glomerular disease are: minor glomerular lesions, microscopic glomerular lesions (nephrotic syndrome), focal segmental glomerulosclerosis, intracapillary proliferative nephritis, thylakoid proliferative nephritis (non-IgA deposition), IgA nephropathy, membranoproliferative nephritis, crescentic nephritis, membranous nephropathy, and sclerosing nephritis. There are many glomerulonephritis (or glomerular disease) that are difficult to identify as primary or secondary even after a kidney biopsy, and still require differential diagnosis with clinical information such as medical history and necessary ancillary tests.
5.What auxiliary tests are usually needed to make a clear diagnosis of nephropathy?
Patients who are suspected of having nephropathy visit the outpatient clinic and usually need to undergo some auxiliary examinations after taking medical history and physical examination. To clarify whether there is kidney disease? Is the kidney disease acute or chronic? Is it glomerulopathy or tubulointerstitial disease? Is it primary or secondary nephropathy? Depending on the purpose, the tests required are different. The following tests are the items to be considered for optional investigation.
(1) Urinalysis: urine routine, urine red blood cell morphology + count, urine albumin/creatinine ratio, 24-hour urine protein quantification, urine lysozyme, urine NAG, urine β2 microglobulin, urine osmolality (12-hour water fast), urine κ and λ, urine bacterial culture + colony count + drug sensitivity, urine exfoliative cell examination, etc.
(2) Blood tests: routine blood, blood biochemistry (in addition to liver and kidney function electrolytes and blood glucose, lipids, uric acid, blood albumin, total protein and serum cystatin C should be included), serum immunological indicators (IgG, IgA, IgM, C3, C4), ANA, anti-dsDNA, ENA peptide, serum protein electrophoresis, blood κ and λ, coagulation indicators (D-dimer), hepatitis B, C, etc. infectious indexes, etc. In special cases, ANCA, anti-GBM antibodies, T-cell, B-cell and IgG subtypes, serum anti-PLA2R antibodies, tumor markers, etc. need to be examined.
(3) Imaging tests: ultrasound of kidney, ureter, bladder and prostate, renal artery ultrasound, renal vein ultrasound, hepatobiliary and pancreatic ultrasound, intravenous pyelogram, CT plain (+ enhancement if necessary) of both kidneys, isotope renogram, renal MRI, electrocardiogram, cardiac ultrasound, chest X-ray or chest CT, etc. Since contrast agents have some adverse effects on the kidneys, strict indications are needed, and if necessary, advance hydration or drink more water after contrast.