I. Introduction
Polycystic kidney is a genetic kidney disease in which multiple cysts appear in the cortex and medulla of the kidney. Its development is familial and can occur in both sexes. According to the mode of inheritance, there are two types.
(1) Autosomal dominant type, which usually does not show symptoms until adulthood;
(2) Autosomal recessive type, which is usually evident in infants.
Autosomal dominant polycystic kidney is common in clinical practice, accounting for about 5-10% of end-stage renal disease. Clinical manifestations mainly include enlarged kidneys, hematuria, proteinuria, hypertension, and renal failure may occur in advanced stages.
The current treatment of this disease is to actively control hypertension and other complications and prevent infection, protect kidney function, and delay the arrival of uremia. In case of uremia, dialysis treatment and kidney transplantation are available.
Polycystic kidney is a genetic disease. According to the genetic characteristics, there are two types of polycystic kidney: autosomal dominant polycystic kidney (ADPKD) and autosomal recessive polycystic kidney (AR PKD). The autosomal dominant polycystic kidney is common. ADPKD is autosomal dominant and is characterized by familial aggregation, with both sexes having an equal chance of being affected, and patients can appear in consecutive generations.
Autosomal dominant polycystic kidney, also known as adult-onset polycystic kidney, is a common polycystic kidney disease. ARPKD is autosomal recessive. Almost all parents have no history of the same disease. Autosomal recessive polycystic kidney, also known as infantile polycystic kidney, is a rare type of polycystic kidney. It often dies shortly after birth, and only a very few milder types survive into childhood or even adulthood.
ADPKD commonly presents with symptoms in adulthood. Whether the cysts are present at birth and grow over time or whether they occur and develop in adulthood is not fully understood. However, in most patients, the lesions may have been present during fetal life. The vast majority have bilateral renal anomalies. The extent of the lesions is not uniform on both sides. They are characterized by cysts of varying sizes throughout the kidney, ranging from just discernible to several centimeters in diameter. Papillae and cones are often indistinguishable. The renal pelvis and calyces are markedly deformed.
The cysts contain urine-like fluid and have a different appearance when bleeding or infected. The progressive growth of the cyst may be related to processes associated with cell proliferation, altered cellular secretion function, and damage to the tissue surrounding the cyst. epithelial cells from ARPKD cysts have been cultured and show properties different from those of ADPKD: endotoxin or Gram-negative bacteria are present in ADPKD cyst fluid, but not in ARPKD cyst fluid.
II. Etiology
The abnormal gene in 90% of ADPKD patients is located on the short arm of chromosome 16, called the ADPKD1 gene, and the gene product is unknown. Many of the genes encoding this region have been elucidated and cloned, and it is expected that in the near future, ADPKD1 can be identified. Another abnormal gene, located on the short arm of chromosome 4 in less than 10% of patients, is known as the ADPKD2 gene, and its coding product is also unknown. The two groups differed in the age of onset, appearance of hypertension, and entry into renal failure.
The exact etiology of the disorder is unknown. Although most of the symptoms do not appear until later in adulthood, they begin to form in fetal life. If the cyst originates in the renal tubules, the nature of the fluid varies depending on the site of origin.
The abnormal proliferation of glomerular intracapsular epithelial cells in polycystic kidney patients is one of the distinctive features of ADPKD, which is in a state of incomplete maturation or redevelopment, highly suggestive of impaired regulation of bacterial development and maturation, leaving the cells in an immature state and thus showing strong proliferation. This abnormal cellular transport is another distinctive feature of ADPKD, manifested by the combination of subunits of Na+-K+-ATP ase closely related to cellular transport, changes in distribution and activity expression; abnormal cellular signaling and changes in ion transport channels. Abnormal extracellular matrix proliferation is the third distinctive feature of ADPKD.
Many studies have now demonstrated that: all these abnormalities have the involvement of active factors related to cell growth. However, the key abnormal links and pathways are not yet understood. In conclusion, altered cell growth and abnormal mesenchymal formation due to genetic defects is one of the important pathogenesis of this disease.
III. Pathological changes
Patients with ADPKD have normal-sized kidneys in the early stage, but in the later stage, they increase in size and show morphological abnormalities, such as heterogeneity of the renal pelvis and calyces, and destruction of the complete structure of the Ming papilla and renal cone. The cysts are spherical in shape and vary in size. Initially, there may be only a few cysts in the kidney, which increase with the progression of the disease, eventually causing the kidney to be occupied by cysts, and the kidney may reach the size of a soccer. Under light microscopy, intact renal structures can be seen between the cysts, ranging from normal manifestations to glomerulosclerosis, tubular atrophy, and interstitial fibrosis, all of which are due to renal ischemia caused by cyst compression. Under electron microscopy, the cystic epithelium shows two morphologies: one resembling the proximal tubular epithelium and the other resembling the distal tubules. The cyst fluid is generally clear and may be purulent or bloody when intracapsular infection or hemorrhage is present.
Both kidneys of ARPKD are significantly larger and heavier, about 10 times the normal size. The shape is smooth and the cut surface reveals pyknotic or columnar cysts with a radial distribution. The epithelial cells were columnar in shape, consistent with the collecting duct cortex cells. The renal pelvis and calyces were compressed by the distended renal parenchyma and narrowed and reduced in size. The hepatic lesions are confined to the portal region and are diffuse, with dilated bile ducts with connective tissue hyperplasia causing periportal fibrosis, which progresses over time to portal hypertension and hepatosplenomegaly.
Although most of the symptoms do not appear until later in adulthood, they begin to form in fetal life. Cysts originate in the renal tubules, and the nature of the fluid varies with the site of origin. If the cyst originates in the proximal tubules, the composition of the cyst fluid such as Na+, K+, CI-, H+, creatinine, urea, etc. is similar to that in the plasma; if it originates in the distal part, the concentration of Na+ and K+ in the cyst fluid is lower, and the concentration of CI-, H+, creatinine and urea is higher.
The abnormal proliferation of intracapsular epithelial cells is one of the distinctive features of ADPKD, in a state of incomplete maturation or redevelopment, highly suggestive of a disorder in the regulation of bacterial development and maturation, leaving the cells in an immature state, thus showing strong proliferative properties. This abnormal cellular transport is another distinctive feature of ADPKD, manifested by the combination of subunits of Na+-K+-ATPase closely related to cellular transport, changes in distribution and activity expression; abnormal cellular signaling and changes in ion transport channels.
Abnormal extracellular matrix proliferation is the third distinctive feature of ADPKD. Many studies have now demonstrated that: all of these abnormalities have the involvement of active factors related to cell growth. However, the key abnormal links and pathways are not yet understood. In conclusion, altered cell growth and abnormal interstitial formation due to genetic defects is one of the important pathogenesis of the disease.
Classification of the disease
Polycystic kidney a class of kidney with hereditary kidney disease, its onset and development also has a certain pattern, the staging of polycystic kidney has the following pattern.
1, occurrence stage: this disease is hereditary disease, generally born with cysts, only smaller, not easy to detect, before 20 years old is generally not easy to find, but if there are cases of polycystic kidney in the family, should be early examination, as well as early observation of the growth of cysts. Pay attention to maintenance.
2.Growing-up period: when patients are 30-40 years old, cysts will have a faster growth, which is called the growing-up period in medical science. The observation should be strengthened during the growth period. Western doctors do not have any treatment for this period and think that no treatment is needed, only symptomatic treatment, such as hypertension, which appears to be very passive. In this period still should be actively treated, the purpose of treatment is to make the cyst no longer grow or delay the growth of cyst by using Chinese medicine which has strong effect of activating blood circulation and removing blood stasis to achieve the effect of prolonging the life of patients, it can also be said that this is the key period of Chinese medicine activating blood circulation and removing blood stasis to delay the growth of cyst.
3, enlargement period: after the patient enters the age of 40, the cyst will have further growth and enlargement, when the cyst exceeds 4cm, to the cyst ulceration of this period, called enlargement period. With the enlargement of cyst, more clinical symptoms will appear, such as lumbar pain, proteinuria, hematuria, elevated blood pressure, etc., which should be closely observed at this time, and in terms of treatment, this period is the key period of combined Chinese and Western treatment. Chinese medicine can be used to activate blood circulation, remove blood stasis, detoxify and drain turbidity, and achieve the purpose of protecting kidney function by removing the cystic fluid that endangers kidney function, so the period of polycystic kidney enlargement is the key period of combined Chinese and Western medicine treatment to protect kidney function.
4.Rupture period: If the cyst continues to grow, it will rupture under the action of some external factors, and after rupture, it should be hospitalized immediately for treatment to actively control infection and prevent sepsis and acute deterioration of renal function for other symptomatic treatment.
5. Uremic phase: treat for uremia, protect kidney function, and perform abdominal hemodialysis in late stage.
V. Diagnosis
1.Family history
2.Clinical manifestations
(1) Urological manifestations: most patients develop symptoms at the age of about 40. Low back or upper abdomen distension, dull pain or renal colic; hematuria; upper urinary tract infection; combined kidney stones; headache, nausea and vomiting, weakness, weight loss and other symptoms of chronic renal failure.
(2) Cardiovascular system manifestations: hypertension, sometimes as the first symptom; may be accompanied by left ventricular hypertrophy, mitral valve prolapse, aortic valve atresia,; intracranial aneurysm and other diseases.
(3) Digestive system manifestations: 30%-40% of patients have liver cysts, 10% have pancreatic cysts, and about 5% have splenic cysts.
3.Physical examination
During physical examination, one or both kidneys can be palpated and nodular in shape. There is pressure pain with infection. 50% of patients have increased waist circumference.
4.Auxiliary examination
(1) Urine routine, no abnormality in early stage, microscopic hematuria in middle and late stage, proteinuria in some patients. There are white blood cells and pus cells in case of stone and infection.
(2) Urine osmolality measurement. The impaired renal concentrating function may appear in the early stage of the lesion with only a few cysts, suggesting that the change is not entirely related to the destruction of renal structure, but may be related to poor renal response to antidiuretic hormone. The decrease in renal concentrating function precedes the decrease in glomerular filtration rate.
(3) Blood creatinine rises progressively with loss of renal compensatory capacity. Creatinine clearance is a more sensitive indicator.
(4) KUB plain film shows enlarged kidney shadow with irregular shape.
(5) IVP shows deformation of the pelvis and calyces under pressure, with a peculiar spider-like shape, flattened and wide calyces, and elongated and thin neck, often in a curved shape.
(6) Ultrasound shows numerous dark areas in both kidneys.
(7) CT shows enlarged kidneys with lobulated shape and most thin-walled cysts filled with fluid.
VI. Classification and its characteristics.
1, perinatal type: severe renal cystic lesion involving 90% of the collecting ducts at perinatal stage, along with a small amount of periportal fibrous proliferation, and death in the perinatal period.
2.Neonatal type: 60% of collecting ducts are involved, with mild periportal fibers proliferation. Symptoms appear in the first month after birth and death is due to renal failure in a few months.
3.Infant type: Infant type shows bilateral renal enlargement, 25% renal tubular involvement, hepatomegaly and splenomegaly with moderate periportal fibrous proliferation. Symptoms appear 3-6 months after birth, and death occurs in childhood due to renal failure.
4. Juvenile type: Juvenile type develops symptoms at the age of 13~19 years. The renal damage is relatively mild, with only 10% or less of the renal tubules showing cystic changes, occasionally progressing to renal failure. Severe fibrous changes in the portal vein area of the liver. Death usually occurs around the age of 20 years due to liver complications and portal hypertension.
VII. Treatment
There is no way to stop the progression of the disease. Early detection is essential to prevent the occurrence and development of complications and to treat the complications that have arisen in a timely and correct manner.
1, general treatment: in general, after the patient is detected polycystic kidney, first of all, we should maintain an optimistic attitude, if it has not yet affected the patient’s normal life, usually need to pay attention to not or eat less to eat too salty, spicy and other stimulating food, work and rest time should be regular, emotionally stable and optimistic; if it affects the patient’s normal life, usually need to pay attention to the above, but also treatment, and the earlier the better. Otherwise, it is too late to let it develop to renal failure uremia.
2, cyst decompression surgery: this surgery reduces the compression of the cyst on the renal parenchyma, protects most of the remaining renal units from extrusion and further damage, improves renal ischemia, restores some renal functional units, and slows down the development of the disease. The key to successful surgery is to perform the surgery as early as possible and the decompression of the cyst must be complete without giving up the decompression of small and deep cysts. Surgery should be performed bilaterally, and generally the interval between bilateral surgeries is more than six months. Late stage disease such as renal function damage in azotemia, uremia stage, whether or not combined with hypertension, decompression treatment is meaningless, surgery can aggravate the disease.
3.Chinese medicine treatment: At present, Chinese medicine takes conservative treatment (taking Chinese medicine) in the treatment of polycystic kidney, which has good effect. Chinese medicine adopts holistic concept and evidence-based treatment, and believes that polycystic kidney is the result of the joint action of external and internal factors, through gradual inflow, gradually let the cyst fluid discharge, so as to achieve the purpose of gradually shrinking the cyst. Although TCM can’t overcome the genetic problem at present, the effect of conservative treatment is incomparable to Western medicine, and it is basically free of toxic side effects and not easy to recur.
4.Dialysis and transplantation: When entering into end-stage renal failure, dialysis should be used immediately, and hemodialysis is preferred. The survival rate of renal transplantation in polycystic kidney is similar to that of patients operated for other reasons, but the concomitant diseases increase the difficulty of postoperative treatment and affect the transplantation effect.
5. Treatment of hematuria: When hematuria occurs, in addition to the treatment given as soon as possible to identify the cause, the activity should be reduced or bed rest. Patients on dialysis or about to be on dialysis, if severe and uncontrollable hematuria occurs repeatedly, transcatheter renal artery embolization can be considered.
6.Infection treatment: renal parenchymal infection and intracapsular infection are the main complications of this disease, and the principle of joint application of antibiotics is generally used.
7, combined with upper urinary tract stone treatment: according to the stone site and size according to the principles of urinary tract stone treatment.
8, hypertension treatment: renal ischemia and activation of the renin-angiotensin-aldosterone system is the main reason for the occurrence of hypertension, and antihypertensive drugs should be selected accordingly.
Without special treatment, the prognosis is extremely poor. Renal insufficiency is often not amenable to dialysis or transplantation due to liver lesions. Portal hypertension with upper gastrointestinal bleeding is often life-threatening. Shunts are contraindicated due to renal failure and infection. Simultaneous kidney and liver damage increases the difficulty of treatment. 9 . The reason is that even if surgery (decompression surgery, or fluid extraction surgery) is used to temporarily solve the problem of large cysts compressing the kidney parenchyma, it cannot solve the problem that small cysts will increase rapidly after the removal of large cysts due to pressure reduction. Surgical treatment is only a stopgap measure and has limitations.
Eight, prevention
4 precautions for polycystic kidney patients
1, prevention of colds: kidney disease patients suffering from polycystic kidney disease is very painful, because unlike other kidney diseases, polycystic kidney is a lifelong genetic disease that needs to be accompanied by a lifetime, even if extra attention, family care, still can not stop the objective reality of cysts continue to swell. At this time, such as a cold, especially repeated colds will make the kidney damage of polycystic kidney patients aggravate a point, which will play a worsening role and accelerate the progress of kidney function damage.
2, control the diet: the reasonable treatment diet of polycystic kidney patients is very important to control the progress of kidney function deterioration. Adopt low salt diet 2~3 grams of edible salt per day is appropriate, eat less diet containing potassium and phosphorus, low protein and low fat diet, eat more vitamin and vegetable crude fiber diet, keep bowel movement smooth.
3, prevention of trauma: the continuous enlargement of polycystic kidney cysts will lead to a constant increase in the intracapsular pressure of the cysts, forcing the patient’s kidneys to increase in size and increase the intra-abdominal pressure. At this time, any slight trauma, such as sprains, bruises, bruises, etc. will increase the internal pressure of abdominal organs or the impact of traumatic external force directly on the enlarged cysts, prompting the rupture and bleeding of cysts with high internal pressure, which is easy to induce infection.
4.Control the blood pressure: Most of the polycystic kidney patients will have high blood pressure before the kidney function is damaged, and we call them polycystic kidney has already developed: the appearance of high blood pressure will accelerate the damage of kidney function, and at the same time, high blood pressure will also damage the heart and cerebrovascular, which will cause serious complications such as stroke due to rupture and bleeding of cerebrovascular tumor of polycystic kidney. Therefore, it is important to control blood pressure to slow down the deterioration of renal function and prevent complications.