C1q Nephropathy (C1q)

C1q Nephropathy is one of the many diseases causing Nephrotic Syndrome. C1q is a normal protein of the immune system and is found throughout the circulatory system. In an individual with C1q Nephropathy the protein is also found deposited in the the kidneys. As an overall disease, it is very similar to Minimal Change Diease and FSGS.

Who Gets C1q

It is not yet known why C1q Nephropathy develops, or why some people deposit C1q in their kidneys. It is thought that deposited C1q protein activates the immune system within the kidney,  resulting in an immune response and inflammation that can eventually cause kidney damage. It is more commonly found in children, but as doctors are becoming more aware of what to look for, they are finding more cases in early adulthood and middle-aged patients.

Signs and Symptoms

C1q Nephropathy presents a complex array of signs and symptoms indicative of renal dysfunction.

Symptoms of C1q Nephropathy may include:

  • Proteinuria
  • Edema
  • Low Blood Albumin Levels
  • High Cholesterol
  • High Blood Pressure
  • Tendency to form Blood Clots
  • Kidney Failure

Diagnosing C1q

C1q Nephropathy has only recently been discovered with the help of specialized electron microscopy and immunofluorescence microscopy  that has “stains” specific for the C1q protein deposits.  Therefore, a kidney biopsy is required to diagnose C1q Nephropathy.

Your Treatment Options

C1q Nephropathy is generally treated in the same manner as Nephrotic Syndrome.  It is important to see a kidney specialist on a regular basis to monitor kidney function, degree of proteinuria, cholesterol and blood pressure.  The most common drug used to treat C1q Nephropathy are steroids.  Many different types of immunosuppressants, or drugs that suppress the immune system, can also be considered.

If remission is not obtained, it is important to be on a medication that reduces the amount of protein in the urine.  These medications are called ACE-inhibitors (angiotensin converting enzyme inhibitors) and ARBs (angiotensin II receptor blockers).

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Clinical trials are another treatment option.

Your doctor helps you find the right study for you. These trials test more targeted treatments with potentially lower risks of side effects.

Some clinical trials enroll patients, based on their genetic testing results, to test the effectiveness of precision-based therapies targeted to specific genetic changes.


Tips For Living With C1q

Patients with C1q benefit from supportive measures including:


Regular, moderate activity helps manage your blood pressure and weight and improves your overall well-being.

Prescription Regimen

Follow your doctor’s instructions and take your medicines as prescribed.

Regular Check-Ups

See your doctor as scheduled to monitor your kidney function and quickly address any changes.


Get help coping with the challenges of living with C1q through support groups like NephCure. Learn more about our how we can support you.


Eat a diet low in salt and processed foods to manage your blood pressure and reduce strain on your kidneys. Learn more about a kidney-friendly diet and get our cookbook.

Your Nephrologist May Also Recommend



Diuretics are important as they help manage fluid retention and edema, which are common complications of kidney dysfunction.



Anticoagulants are essential for rare kidney disease patients to prevent the formation of blood clots.



Blood Pressure medications to lower high blood pressure. Statins to lower the cholesterol level.



Vitamins play a crucial role in supporting overall health and mitigating potential complications.

Related Resources


Mental Health and Chronic Illness

Informational Documents

Low-Potassium Pocket Guide

Educational Materials

Kidney Disease FAQs

Fact Sheet

Nephrotic Syndrome


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