Can IgA Nephropathy Cause Blood or Protein with Normal eGFR?

Yes, you can absolutely have IgA nephropathy even if your eGFR (estimated glomerular filtration rate) is completely normal. However, persistent blood or protein in the urine can occur with many conditions—including infections, kidney stones, or other glomerular diseases—so IgA nephropathy is generally confirmed by a kidney biopsy ^[1]. A normal eGFR means your kidneys are still effectively filtering waste from your blood, but the presence of blood or protein indicates that the filters themselves are inflamed or injured ^[2][3].

Why Does Urine Show Damage if the eGFR is Normal?

IgA nephropathy begins when abnormal IgA proteins clump together and form immune complexes ^[4]. These complexes get trapped in the mesangium (the supporting tissue between the kidney’s capillary loops, within the filtering units called glomeruli) ^[2]. This triggers an inflammatory response and activates the complement system, a part of your body’s immune defense ^[5]. This inflammation causes changes that increase the permeability of the delicate filtration barrier, essentially creating “leaks” ^[2][4].

Red blood cells and protein leak through these more permeable barriers into your urine, causing hematuria (blood in the urine) and proteinuria (protein in the urine) ^[2][3]. At this stage, your kidneys compensate well. Because you have millions of these filters, a large number can be inflamed before the overall filtration capacity starts to measurably drop ^[1]. A normal eGFR is an encouraging sign, but it does not mean the condition is completely inactive.

Why Regular Monitoring Remains Crucial

Even with a normal eGFR, regular monitoring helps your care team understand your long-term risk and determine if treatment is needed. Treatment decisions—such as starting kidney-protective medications like ACE inhibitors or ARBs—are based on your overall risk, blood pressure, and protein levels, not just waiting for your eGFR to fall ^[6].

Tracking Proteinuria (Protein in Urine)

The amount of protein in your urine is one of the strongest predictors of long-term kidney health in IgA nephropathy ^[7]. Doctors often look at your time-averaged proteinuria (the average across multiple tests over time) using tests like a 24-hour collection or a spot urine protein-to-creatinine ratio (UPCR) or albumin-to-creatinine ratio (UACR). Having a time-averaged urine protein level above 0.5 grams per day is associated with a faster decline in kidney function ^[8][9]. Current guidelines often aim to reduce proteinuria as much as possible, sometimes targeting less than 0.3 grams per day, though this is an individualized goal rather than a universal guarantee ^[10].

Watching Hematuria Trends

Microscopic blood in the urine often fluctuates. Persistent or worsening microscopic hematuria is associated with a higher risk of disease progression in IgA nephropathy ^[11][12]. However, hematuria is not a perfect measure of active inflammation. Blood in the urine can also be caused by infections, stones, or menstrual contamination, and its disappearance does not guarantee that your risk has vanished completely ^[13]. It is one piece of the puzzle interpreted alongside your protein levels and kidney function.

Blood Pressure Control

Blood pressure is a key modifiable risk factor and a primary treatment target ^[14]. High blood pressure puts extra physical stress on already inflamed kidney filters. Blood pressure targets are highly individualized based on how they are measured (standardized office versus home readings), your age, and your tolerance. Current guidelines suggest a standardized office systolic blood pressure target of less than 120 mm Hg if tolerated, but you should never change your blood pressure medications or targets without your doctor’s supervision ^[14].

Measuring the eGFR Slope

Your eGFR is an estimate that can fluctuate due to hydration, acute illnesses, or laboratory variation. Values above 90 are often simply reported as “>90.” Therefore, nephrologists track your eGFR slope—the trend of repeated measurements taken when you are clinically stable over months and years ^[15]. A steady, steeper decline in eGFR is a warning sign that the disease may be progressing, even if the absolute number is still within the normal range ^[15][16].

Assessing Overall Risk

Your doctor will use multiple factors to estimate your risk. Validated tools (like the International IgAN Prediction Tool) incorporate your eGFR, blood pressure, and proteinuria, alongside your age, race/ethnicity, medication use, and specific findings from your kidney biopsy (such as the MEST-C score) ^[17]. No single number determines your outcome.

When to Contact Your Care Team

Not seeing red urine does not mean microscopic hematuria has resolved, but newly visible red or cola-colored urine—especially during a respiratory infection—warrants letting your doctor know. Seek prompt medical evaluation if you experience:

• New or severe swelling (edema) in your legs, face, or abdomen
• A marked, sudden decrease in how much you urinate
• Shortness of breath
• Severe headaches or very high home blood pressure readings
• Symptoms of a urinary tract infection (painful urination, fever)