Berger’s disease, which doctors usually call IgA nephropathy, is a kidney disease driven by the immune system rather than by anything you did. The kidneys’ tiny filters get damaged by deposits of an antibody the body normally uses to fight infections. It is one of the most common kidney diseases that starts in the filters, and it often develops quietly over years rather than suddenly. For many people the outlook depends less on the diagnosis itself than on how well protein in the urine and blood pressure are kept down, and treatment options have grown in the last few years.1PubMed. Treatment of patients with IgA nephropathy: a call for a new paradigm
What Causes Berger’s Disease
IgA is an antibody your body makes to protect the lining of the throat, nose and gut. People with this disease have more of a version of IgA that is missing some of its normal sugar coating.2PubMed Central. Pathogenesis of IgA Nephropathy: Current Understanding and Implications for Development of Disease-Specific Treatment That alone isn’t enough, though: close relatives of patients often have high levels of it and perfectly healthy kidneys.3PubMed Central. The pathogenesis of IgA nephropathy and implications for treatment The disease needs further steps. In some people the immune system makes other antibodies that attack the altered IgA.4PubMed Central. IgA Nephropathy: Beyond the Half-Century The two stick together into clumps that travel in the blood.5PubMed Central. The pathogenesis of IgA nephropathy and implications for treatment The clumps then settle in the kidney’s filters, where they trigger cells to multiply and release signals that cause inflammation and scarring.6PubMed Central. The pathogenesis of IgA nephropathy and implications for treatment Another part of the immune system amplifies this damage and is linked to faster worsening.7Journal of Nephrology. Role of complement in IgA nephropathy Because the body is making antibodies against its own altered IgA, the disease is often called autoimmune. That also helps explain why immune-calming drugs can help.
The strongest inherited risk lies in immune-system genes that help the body recognise threats.8PubMed Central. HLA Has Strongest Association with IgA Nephropathy in Genome-Wide Analysis These same risk genes are linked to other immune conditions such as type 1 diabetes and inflammatory bowel disease.9PubMed Central. Geographic Differences in Genetic Susceptibility to IgA Nephropathy: GWAS Replication Study and Geospatial Risk Analysis The disease is most common in Asia, less in Europe, and least in Africa, partly reflecting how these genes are spread.10PubMed Central. Ethnicity and IgA nephropathy: worldwide differences in epidemiology, timing of diagnosis, clinical manifestations, management and prognosis
Throat and gut infections can push IgA production up sharply and flare the disease.11Ovid. The mucosa-kidney axis in IgA nephropathy A cold or sore throat can briefly raise the amount of altered IgA in the blood. If clumps are already forming, that surge can produce more of them and cause a flare, such as pink urine. An unbalanced mix of gut bacteria is also linked to higher levels of the altered IgA.12Nephrology Dialysis Transplantation. IgA nephropathy: gut microbiome regulates the production of hypoglycosilated IgA1 via the TLR4 signaling pathway
Nothing a person ate, drank or did is known to have started the disease. It is not contagious, even though infections can trigger flares.
Symptoms and Warning Signs
The most typical sign is blood in the urine, especially during or soon after a cold, sore throat or chest infection.13National Kidney Foundation. IgA Nephropathy (IgAN) Urine may turn pink, dark brown or cola-coloured.14National Kidney Foundation. IgA Nephropathy (IgAN) In early disease, though, the blood is often visible only under a microscope, so it turns up on a routine urine test.15National Kidney Foundation. IgA Nephropathy (IgAN)
If your urine turns red after a cold, note the date and how it relates to the infection, then contact your doctor and ask for a urine test, even if the colour clears. Visible blood at the same time as a sore throat is one clue that points toward this disease, but only tests can confirm it.
Protein and blood pressure are quieter clues. Damaged filters leak protein into the urine. Foamy urine, swelling in the ankles or around the eyes, and high blood pressure can follow. Many adults have no symptoms at all until a check-up finds abnormal urine or raised blood pressure. Many people learn of it only through a routine urine test, such as one at a work, insurance or school check.
Some signs need prompt attention: much less urine than usual, sudden swelling or breathlessness, or very high blood pressure readings at home.
How Doctors Diagnose It
Urine tests measure blood and protein. Blood tests give an eGFR, an estimate of how well your kidneys filter, where about 90 or more is normal. Blood and protein in the urine show that the filters are leaking, but many kidney conditions cause the same findings, and function can stay normal for years. That is why abnormal urine that keeps showing up usually leads to a referral to a kidney specialist.
The only way to confirm the disease is a kidney biopsy, a small sample of kidney taken with a needle. The defining finding is IgA as the main antibody deposited in the kidney filters.16PubMed. Diagnosis and classification of IgA nephropathy Doctors must also rule out lupus, which can leave similar deposits.17PubMed Central. Immunofluorescence Use and Techniques in Glomerular Diseases: A Review The biopsy report often includes a MEST-C score that grades inflammation and scarring.18PubMed Central. Utilizing the MEST score for prognostic staging in IgA nephropathy
A biopsy is done under local anaesthetic with ultrasound guidance. You lie still for several hours afterward to prevent bleeding, and some blood in the urine for a day or two is common.
A similar kidney picture also appears in IgA vasculitis (Henoch-Schönlein purpura). That condition adds a skin rash, joint pain or stomach pain, and it is mainly a childhood illness, while Berger’s disease peaks between 15 and 30.
How Serious Is It and What Predicts the Outlook
Outcomes vary widely. In one long-term group about 1 in 5 patients reached kidney failure over 15 years.19PubMed Central. Utilizing the MEST score for prognostic staging in IgA nephropathy In some settings with later diagnosis, only about a third kept working kidneys at 10 years.20PubMed Central. Prognostic value of the MEST-C score in long-term outcomes of immunoglobulin A nephropathy patients: Insights from a developing country
Kidney function at diagnosis is the strongest predictor of how kidneys fare over 10 years.21PubMed Central. Long-Term Outcomes in IgA Nephropathy Higher protein in the urine over time means faster loss of function.22PubMed Central. Long-Term Outcomes in IgA Nephropathy Every 10% drop in urine protein lowers the risk of kidney failure or death by about 11%.23PubMed Central. Long-Term Outcomes in IgA Nephropathy High blood pressure, protein of 1 gram a day or more, and severe biopsy damage each add risk.24PubMed Central. Predicting the Risk for Dialysis or Death in IgA Nephropathy Scarring on the biopsy predicts a worse course more than active inflammation does.25PubMed Central. Prognostic Utility of the MEST-C Score Combined With Clinical Parameters in Hispanic Patients With IgA Nephropathy People of Asian background tend to progress somewhat faster.26PubMed Central. Long-Term Outcomes in IgA Nephropathy These figures describe groups of patients, and a single person’s course can be better or worse than the average.
Age, background and the scarring already on the biopsy cannot be changed. Blood pressure and protein leakage can be lowered with treatment and everyday habits, and much of the effort in care goes there.
At each visit, these are worth tracking:
- Urine protein: ideally below 1 gram a day, and lower if possible.
- Blood pressure: usually aiming under about 120 to 130 systolic.
- Kidney filtering score: the trend over time rather than one reading.
Standard Treatment to Protect the Kidneys
ACE inhibitors or ARBs, common blood pressure pills like lisinopril or losartan, reduce urine protein and protect kidney function.27PubMed. ACEI/ARB therapy for IgA nephropathy: a meta analysis of randomised controlled trials They are usually prescribed even if blood pressure is normal. SGLT2 inhibitors, first developed for diabetes, cut urine protein by about a quarter within six months.28PubMed Central. Effect of SGLT2 inhibitors on the proteinuria reduction in patients with IgA nephropathy A small early dip in the kidney filtering score after starting these drugs is expected and not a sign of harm.
ACE inhibitors and ARBs ease pressure inside the filters, which reduces how much protein leaks through. The benefit lasts only while the drug is taken, so stopping lets leakage rise again. Doctors usually increase the dose to the highest the person tolerates, guided by blood pressure and protein levels.
ACE inhibitors can cause a dry, persistent cough, and switching to an ARB often solves it. Dizziness on standing can occur, especially at first. These drugs should not be used in pregnancy, so anyone who may become pregnant should discuss this with the doctor before starting. Blood tests after starting check potassium, which these drugs can raise, and kidney function.
Everyday steps support the medicines. Cutting salt helps blood pressure drugs work better. Regular use of painkillers like ibuprofen strains the kidneys, so avoid it. Stopping smoking and keeping a healthy weight also help.
Gluten triggered disease in mice, and some patients improved without it.29PubMed. The gut-kidney axis in IgA nephropathy: role of microbiota and diet on genetic predisposition Evidence in people is thin, so a gluten-free diet is worth discussing mainly if you also have coeliac disease.
Steroids and Newer Targeted Drugs
Adding steroids to standard care brings more people into remission.30PubMed Central. Systemic and targeted steroids for the treatment of IgA nephropathy But they cause more side effects, and adding stronger immune drugs led to serious harms in one trial.31PubMed Central. Systemic and targeted steroids for the treatment of IgA nephropathy Low-dose steroids reduce protein but haven’t clearly slowed loss of kidney function.32PubMed Central. Efficacy and safety of steroids glucocorticoids compared with supportive therapy for IgA nephropathy: a systematic review and meta-analysis
Raised blood sugar and weight gain are common, and mood and sleep changes can occur. Infections are more likely, so report fevers early.
Targeted medicines are now approved. Nefecon is budesonide released in the gut, where much of the altered IgA is thought to be made.33PubMed. Targeted-release budesonide versus placebo in patients with IgA nephropathy (NEFIGAN): a double-blind, randomised, placebo-controlled phase 2b trial Over 2 years it cut the loss of kidney function to about a third of what happened on placebo.34PubMed. Efficacy and safety of a targeted-release formulation of budesonide in patients with primary IgA nephropathy (NefIgArd): 2-year results from a randomised phase 3 trial Sparsentan, which blocks two hormones that tighten kidney vessels, and iptacopan, which blocks the part of the immune system that amplifies kidney damage, are also approved.35PubMed. Treatment of patients with IgA nephropathy: a call for a new paradigm Drugs that block signals driving IgA-producing cells are in late-stage trials.36PubMed. Drugs in Development to Treat IgA Nephropathy
Doctors usually consider these options after a few months of standard care and lifestyle steps if protein in the urine remains high. They weigh the level of protein, the kidney filtering score and the biopsy findings. A person with low protein and stable function may never need them.
Useful questions to ask: Is my protein level high enough to qualify? What side effects should I watch for? Is it covered by insurance, as newer drugs are expensive? Am I eligible for a clinical trial?
Berger’s Disease in Children
Visible blood in urine occurs in 60 to 88% of affected children versus 15 to 20% of adults.37PubMed Central. Is Childhood IgA Nephropathy Different From Adult IgA Nephropathy? A Narrative Review Children also have more active inflammation and less scarring on biopsy.38PubMed Central. Is Childhood IgA Nephropathy Different From Adult IgA Nephropathy? A Narrative Review Kidney failure at 5 years is about 3% in children versus 13% in adults.39PubMed Central. Is Childhood IgA Nephropathy Different From Adult IgA Nephropathy? A Narrative Review Children with high protein respond better to steroids than adults.40PubMed Central. Are children with IgA nephropathy different from adult patients? A child with visible blood in the urine should be seen and tested, even if the colour clears.
Parents can expect regular urine checks, especially after colds. Steroids are used more readily in children, and long-term follow-up into adulthood is still needed. Some children do develop persistent protein leakage and lasting damage, so monitoring continues even when a child seems well.
Can It Come Back After a Kidney Transplant
The disease returns in 20 to 60% of transplant recipients, depending on how closely it is looked for.41PubMed Central. Treatment of Recurrent IgA Nephropathy After Kidney Transplantation: Case Report and Comprehensive Literature Review In one large group about 23% had confirmed return within 15 years.42PubMed Central. Recurrence of IgA Nephropathy after Kidney Transplantation in Adults When it returns, the new kidney is more likely to fail.43PubMed Central. Recurrence of IgA Nephropathy after Kidney Transplantation in Adults Younger age and lasting protein after transplant raise the risk.44PubMed Central. Treatment of Recurrent IgA Nephropathy After Kidney Transplantation: Case Report and Comprehensive Literature Review
A transplant is still a good option. It gives much better health and survival than dialysis for most people with kidney failure, and many transplanted kidneys keep working for many years even where the disease returns.
Protecting the new kidney means taking anti-rejection drugs exactly as prescribed. The same protein and blood pressure checks apply, and recurrence is treated with the same standard drugs.