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Proteinuria

Updated : May 7, 2024





Background

Proteinuria is a condition which contain excess protein in urine. Kidney filters the waste products and other molecules from the blood and reabsorb the proteins. When the kidney damage or cannot filter properly, it can lead to the protein to pass though the urine. The proteins found in the urine are albumin, globulin and enzymes. The amount of protein measure by mg/dL or gm/24 hours. Proteinuria with the eGFR may indicate the chronic kidney disease (CKD). It suggests the high risk of renal disease with hypertension and cardiovascular disease (CVD). 

Epidemiology

Proteinuria is a common condition. It occurs in different age groups. The mild cases are in a small percentage. The rate increases with age. As the age increases, kidney are at risk of damage and chronic conditions like hypertension and diabetes is also common on the old people. The related factors that affect the proteinuria are gender, race, ethnicity, genetic factors, health care access and economic status. Lifestyle, environmental exposures and genetic predisposition may affect the geographical variations. People who live in that area are at high risk of diabetes, hypertension or infectious disease. African Americans, Hispanics, and Native Americans are at high risk of this disease than the Caucasians. 

Anatomy

Pathophysiology

Proteinuria is a disease in which protein is present in urine. It is caused by the damage in kidney filtration and process of reabsorption. Kidney filter blood and remove waste products and absorb the essential protein in glomeruli. When the kidney damages, glomerular filtration barrier may be affected. This allows the proteins like albumin go to urine. Diseases like glomerulonephritis, diabetic nephropathy, and hypertensive nephrosclerosis can also affect the glomeruli. This also allow proteins to go to the urine. Diseases like diabetes and hypertension can lead to microvascular damage in the kidneys. The loss of proteins in the urine can lead to hypoalbuminemia. It reduces the oncotic pressure in the blood vessels and cause leak of the fluid in he tissues. It can lead to edema. Chronic proteinuria can cause kidney damage and chronic kidney disease.  

Persistent proteinuria is a marker of kidney damage and is associated with chronic kidney disease progression. Identifying and addressing the underlying causes is crucial to prevent further renal impairment and manage associated complications. 

Etiology

Obesity and Metabolic Syndrome 

Obesity and metabolic syndrome have been associated with an increased risk of proteinuria. These conditions can lead to proteinuria because of the effect on the insulin resistance and inflammatory response.  

Genetic Disorders 

Genetic diseases like Alport disease and hereditary nephritis affect the structure and function of the kidney.  

Autoimmune Diseases 

Autoimmune diseases like lupus affect the kidney and lead to glomerular damage.  

Genetics

Prognostic Factors

Proteinuria is a indicate the damage of kidney. It is often associated with CKD. Management of the diseases like diabetes and hypertension can decrease the malfunction of the kidney. Other health conditions and complications affect the prognosis.  

Clinical History

Sometimes proteinuria is asymptomatic. It can be detected during the daily laboratory tests. It is necessary to have the information related to the patient history, symptoms related to renal failure, connective tissue diseases, leg swelling, weight changes, skin rashes, arthralgias, mouth ulcers, loin pain, shortness of breath, abdominal pain, pleuritic chest pain or rigors. Information related to the changes in the urine form like red or smoky or frothy urine, medical complications like hypertension, heart failure, diabetes mellitus is necessary before the treatment. Other includes the medications like nephrotoxic drugs used in past or present, angiotensin converting enzyme inhibitors, loop diuretics and antibiotics like aminoglycosides, penicillamine, and herbal medicines. A detailed family history is necessary to determine possible causes and risk factors of proteinuria. It helps to diagnose and treat the disease.  

Physical Examination

The physical examination focuses on edema, rashes, muscle wasting, abdominal bruits, and hemorrhages, retinopathy, joint swelling, chronic liver disease, organomegaly, cardiac murmurs, and lymphadenopathy. Blood pressure measurement is necessary to diagnose and understand the condition of patients. 

Age group

Associated comorbidity

Associated activity

Acuity of presentation

Differential Diagnoses

  • Amyloidosis  
  • Dyslipidemia  
  • Vasculitis  
  • Hypertension  
  • Dehydration  
  • Post renal transplant  
  • Preeclampsia  
  • Orthostatic proteinuria 

Laboratory Studies

Imaging Studies

Procedures

Histologic Findings

Staging

Treatment Paradigm

ACE inhibitors have shown excellent efficacy in the treatment of proteinuria. It I sused in the cases of where protein excretion level is high. They require close monitoring of creatinine and potassium level. ACE inhibitors and ARBs do not differ much in terms of effectiveness or adverse effects. It is recommended by patient response to the treatment and health care provider experience. ACE inhibitors reduce the risk of the renal disease and decreases the chance of renal replacement therapy. As per the Kidney Health Australia, there is 50% reduction in the cases of the proteinuria from 6 months to 1 years. This is because of the reduction in the risk of the renal disease progression. 

by Stage

by Modality

Chemotherapy

Radiation Therapy

Surgical Interventions

Hormone Therapy

Immunotherapy

Hyperthermia

Photodynamic Therapy

Stem Cell Transplant

Targeted Therapy

Palliative Care

Role of Diuretics

The individual who are at a risk of fluid overload, they require the diuretic therapy and a salt free diet. Aldosterone antagonists is used to treat the proteinuria. ACE inhibitors with aldosterone antagonists reduces the death in heart failure patient but increases with the hyperkalemia and gynecomastia risk. 

Role of ACE Inhibitors

Study shows that ACE inhibitors is effective to treat the proteinuria. It is mainly used in the patients with high level of proteinuria. It is effective in patients with diabetis and nondiabetic. It also reduces the risk of the renal disease progression and decreases the chance of renal replacement therapy 

Medication

Media Gallary

Proteinuria

Updated : May 7, 2024




Proteinuria is a condition which contain excess protein in urine. Kidney filters the waste products and other molecules from the blood and reabsorb the proteins. When the kidney damage or cannot filter properly, it can lead to the protein to pass though the urine. The proteins found in the urine are albumin, globulin and enzymes. The amount of protein measure by mg/dL or gm/24 hours. Proteinuria with the eGFR may indicate the chronic kidney disease (CKD). It suggests the high risk of renal disease with hypertension and cardiovascular disease (CVD). 

Proteinuria is a common condition. It occurs in different age groups. The mild cases are in a small percentage. The rate increases with age. As the age increases, kidney are at risk of damage and chronic conditions like hypertension and diabetes is also common on the old people. The related factors that affect the proteinuria are gender, race, ethnicity, genetic factors, health care access and economic status. Lifestyle, environmental exposures and genetic predisposition may affect the geographical variations. People who live in that area are at high risk of diabetes, hypertension or infectious disease. African Americans, Hispanics, and Native Americans are at high risk of this disease than the Caucasians. 

Proteinuria is a disease in which protein is present in urine. It is caused by the damage in kidney filtration and process of reabsorption. Kidney filter blood and remove waste products and absorb the essential protein in glomeruli. When the kidney damages, glomerular filtration barrier may be affected. This allows the proteins like albumin go to urine. Diseases like glomerulonephritis, diabetic nephropathy, and hypertensive nephrosclerosis can also affect the glomeruli. This also allow proteins to go to the urine. Diseases like diabetes and hypertension can lead to microvascular damage in the kidneys. The loss of proteins in the urine can lead to hypoalbuminemia. It reduces the oncotic pressure in the blood vessels and cause leak of the fluid in he tissues. It can lead to edema. Chronic proteinuria can cause kidney damage and chronic kidney disease.  

Persistent proteinuria is a marker of kidney damage and is associated with chronic kidney disease progression. Identifying and addressing the underlying causes is crucial to prevent further renal impairment and manage associated complications. 

Obesity and Metabolic Syndrome 

Obesity and metabolic syndrome have been associated with an increased risk of proteinuria. These conditions can lead to proteinuria because of the effect on the insulin resistance and inflammatory response.  

Genetic Disorders 

Genetic diseases like Alport disease and hereditary nephritis affect the structure and function of the kidney.  

Autoimmune Diseases 

Autoimmune diseases like lupus affect the kidney and lead to glomerular damage.  

Proteinuria is a indicate the damage of kidney. It is often associated with CKD. Management of the diseases like diabetes and hypertension can decrease the malfunction of the kidney. Other health conditions and complications affect the prognosis.  

Sometimes proteinuria is asymptomatic. It can be detected during the daily laboratory tests. It is necessary to have the information related to the patient history, symptoms related to renal failure, connective tissue diseases, leg swelling, weight changes, skin rashes, arthralgias, mouth ulcers, loin pain, shortness of breath, abdominal pain, pleuritic chest pain or rigors. Information related to the changes in the urine form like red or smoky or frothy urine, medical complications like hypertension, heart failure, diabetes mellitus is necessary before the treatment. Other includes the medications like nephrotoxic drugs used in past or present, angiotensin converting enzyme inhibitors, loop diuretics and antibiotics like aminoglycosides, penicillamine, and herbal medicines. A detailed family history is necessary to determine possible causes and risk factors of proteinuria. It helps to diagnose and treat the disease.  

The physical examination focuses on edema, rashes, muscle wasting, abdominal bruits, and hemorrhages, retinopathy, joint swelling, chronic liver disease, organomegaly, cardiac murmurs, and lymphadenopathy. Blood pressure measurement is necessary to diagnose and understand the condition of patients. 

  • Amyloidosis  
  • Dyslipidemia  
  • Vasculitis  
  • Hypertension  
  • Dehydration  
  • Post renal transplant  
  • Preeclampsia  
  • Orthostatic proteinuria 

ACE inhibitors have shown excellent efficacy in the treatment of proteinuria. It I sused in the cases of where protein excretion level is high. They require close monitoring of creatinine and potassium level. ACE inhibitors and ARBs do not differ much in terms of effectiveness or adverse effects. It is recommended by patient response to the treatment and health care provider experience. ACE inhibitors reduce the risk of the renal disease and decreases the chance of renal replacement therapy. As per the Kidney Health Australia, there is 50% reduction in the cases of the proteinuria from 6 months to 1 years. This is because of the reduction in the risk of the renal disease progression. 

The individual who are at a risk of fluid overload, they require the diuretic therapy and a salt free diet. Aldosterone antagonists is used to treat the proteinuria. ACE inhibitors with aldosterone antagonists reduces the death in heart failure patient but increases with the hyperkalemia and gynecomastia risk. 

Study shows that ACE inhibitors is effective to treat the proteinuria. It is mainly used in the patients with high level of proteinuria. It is effective in patients with diabetis and nondiabetic. It also reduces the risk of the renal disease progression and decreases the chance of renal replacement therapy