Glomerulonephritis — Nephrologist Valencia

What is glomerulonephritis?

Glomerulonephritis is inflammation of the glomeruli — the millions of tiny filtering units inside the kidneys where blood is cleaned and urine production begins. When these filters become inflamed, they leak blood and protein into the urine and lose their ability to remove waste and excess fluid efficiently. The result can be anything from a mild, self-limiting illness to a serious condition that, untreated, progresses to chronic kidney disease.

Glomerulonephritis is not a single disease but a family of related conditions. They can arise on their own (primary) or as part of a wider illness affecting the whole body (secondary), such as lupus or infections.

Dr. Juan Luis Villaro Gumpert, nephrologist at Hospital Vithas 9 de Octubre in Valencia, has a particular interest in glomerular disease — the focus of his PhD research — and brings that specialist, evidence-based perspective to every patient assessment.

The main types

Several distinct patterns are recognised, each with its own behaviour and treatment:

• IgA nephropathy (Berger’s disease): the most common glomerulonephritis worldwide, caused by deposits of IgA antibodies in the glomeruli. It often presents with episodes of visible blood in the urine, sometimes following a respiratory infection.
• Membranous nephropathy: a leading cause of heavy protein loss (nephrotic syndrome) in adults, frequently driven by antibodies against a podocyte protein called PLA2R.
• Minimal change disease: the most common cause of nephrotic syndrome in children, though it also affects adults. The kidney looks almost normal under a standard microscope but leaks large amounts of protein.
• Focal segmental glomerulosclerosis (FSGS): scarring of parts of some glomeruli, an important cause of nephrotic syndrome that can be more resistant to treatment.

What causes it?

Many cases are immune-mediated, where the body’s own immune system mistakenly targets the glomeruli. Triggers and associations include infections (such as streptococcal or viral illnesses), autoimmune diseases like systemic lupus erythematosus, vasculitis, and certain medications. In some people no clear cause is found. Genetic factors play a role in some forms, particularly FSGS.

Recognising the symptoms

The hallmark signs reflect leaky, inflamed filters:

• Haematuria — blood in the urine, which may be visible (cola- or tea-coloured) or detected only on testing.
• Proteinuria — protein loss that makes urine appear foamy or frothy.
• Oedema — swelling of the face, ankles, legs or abdomen as fluid and protein balance is disturbed.
• Hypertension — raised blood pressure as fluid is retained.

When protein loss is heavy, the combination is called nephrotic syndrome; when blood, reduced filtration and high blood pressure dominate, it is called nephritic syndrome. Many patients sit somewhere between the two.

How it is diagnosed

Diagnosis begins with a careful history and a urinalysis, which reveals blood and protein and, under the microscope, characteristic red-cell casts. Blood tests assess kidney function, immune markers and antibodies such as anti-PLA2R. An ultrasound checks kidney size and structure.

The definitive test is usually a kidney biopsy, in which a small tissue sample is examined to identify the precise type of glomerulonephritis. This is essential because the correct treatment differs markedly between the types, and the biopsy also reveals how much active inflammation versus permanent scarring is present.

Treatment

Treatment depends entirely on the specific diagnosis and severity, and aims both to control symptoms and to protect long-term kidney function:

• ACE inhibitors or ARBs lower blood pressure and reduce protein loss, protecting the kidneys in nearly all forms.
• Immunosuppression — corticosteroids and agents such as mycophenolate, rituximab or cyclophosphamide — is used in immune-driven and more aggressive forms.
• Diuretics and salt restriction help control fluid overload and swelling.
• Treating the underlying cause, such as an infection or lupus, is central in secondary disease.

With early, accurate diagnosis and tailored treatment, many patients achieve remission and preserve their kidney function for the long term. Dr. Villaro combines this individualised care with clear English-language explanations, so that international patients in Valencia fully understand their condition and can maintain continuity of care wherever they live.