Dr Christopher
Lawrence

eGFR stands for estimated Glomerular Filtration Rate — it is a measure of how well your kidneys are filtering waste from the blood. It is calculated from a simple blood test (serum creatinine) alongside your age and sex.

A normal eGFR is above 90 mL/min/1.73m². Chronic Kidney Disease (CKD) is classified into stages based on how low this number has fallen:

• Stage 1: eGFR ≥ 90 — kidney damage present but function near normal
• Stage 2: eGFR 60–89 — mildly reduced
• Stage 3a: eGFR 45–59 — mildly to moderately reduced
• Stage 3b: eGFR 30–44 — moderately to severely reduced
• Stage 4: eGFR 15–29 — severely reduced
• Stage 5: eGFR < 15 — kidney failure

The stage alone does not tell the whole story. The trend over time and the level of protein in your urine (albumin-to-creatinine ratio, or ACR) are equally important in understanding your risk and guiding your care.

Healthy kidneys filter the blood but keep protein inside the body. When protein appears in the urine — called proteinuria — it suggests the kidney's filter is not working as it should.

The most important protein to measure is albumin, measured as the albumin-to-creatinine ratio (ACR) in a urine sample. A raised ACR — called albuminuria — is an independent marker of kidney risk and cardiovascular risk, even at very low levels.

Causes include diabetes, high blood pressure, glomerulonephritis (inflammation of the kidney filter), and many other conditions. The cause matters — and finding it early opens the door to treatment that can significantly slow progression.

A kidney transplant replaces the function of failed kidneys with a donor organ, placed in the lower abdomen (the original kidneys are usually left in place). Transplanted kidneys can function for many years — but require careful, lifelong monitoring and immunosuppression (medication to prevent rejection).

Monitoring typically involves regular blood tests (creatinine, tacrolimus levels), urine protein measurements, blood pressure checks, and periodic ultrasound scans. When problems are detected, a biopsy may be needed to identify the cause precisely.

Dr Lawrence also offers access to advanced molecular monitoring — see the Advanced Transplant Diagnostics section for more information on cfDNA and MMDx.

The relationship between hypertension and kidney disease runs in both directions. High blood pressure is one of the most common causes of CKD; and CKD itself raises blood pressure as the kidneys' ability to regulate salt and fluid balance deteriorates. This creates a cycle that requires careful management.

Blood pressure targets are lower in kidney disease than in the general population — particularly when proteinuria is present. Medications called ACE inhibitors or ARBs are often preferred because they both lower blood pressure and reduce protein leak, offering dual kidney protection.

A first appointment typically lasts 45–60 minutes. Dr Lawrence will want to review your full medical history, any previous blood and urine tests, imaging, and medications. It is helpful to bring:

• A list of all current medications and doses
• Any recent blood test results or letters from your GP
• Any imaging reports (ultrasound, CT, MRI)
• A urine sample if possible (first morning urine is ideal)

The consultation will usually conclude with a clear explanation of the findings, a formulated diagnosis or differential, and a management plan — including any additional tests needed. Dr Lawrence aims to ensure you leave with a clear understanding of your condition and next steps.

Dietary recommendations in kidney disease depend on the stage and cause, but some general principles apply widely:

• Salt: Limiting salt intake helps blood pressure control and reduces fluid retention — aim for under 6g per day
• Protein: Moderating protein intake (not eliminating it) may reduce the burden on damaged kidneys in later-stage CKD
• Potassium: When kidneys fail to excrete potassium normally, high-potassium foods (bananas, potatoes, tomatoes) may need to be limited
• Phosphate: Late-stage CKD often requires restriction of phosphate-rich foods (dairy, processed meats, fizzy drinks)

Dietary advice should always be personalised — what applies to one patient may not apply to another. A renal dietitian referral is often part of CKD management.

A 24-hour urine collection measures how much of a substance (such as protein, creatinine, calcium, or uric acid) your kidneys produce over a full day. To get an accurate result, every drop of urine during that period must be collected.

Before you start — collect the right bottles

Collect your bottles from the hospital pathology department before the day of collection. Different tests require different bottles:

• Plain bottles — for creatinine clearance, protein, urate, and urine osmolality
• Strong acid containers (marked with a hazard label) — for calcium, phosphate, oxalate, and metanephrins. Handle with care; splashes can cause skin burns.

If there is any chance you might produce more than 2.5 litres, take a second bottle. It is better to return an unused bottle than to have to repeat the entire collection.

You will also need a clean 1-litre plastic jug to use as an intermediate receptacle. Do not pass urine directly into the collection bottle. Discard the jug after the collection is complete.

Step-by-step instructions

1. Choose a convenient day when you can collect every void and return the sample the following morning.
2. On waking, pass urine as normal and discard this first sample. Note the time — this is the start of your 24-hour period.
3. From this point, collect every urine void into your jug and transfer to the collection bottle.
4. The following morning, collect the first void of the day. Note the time — this is the end of the 24-hour period. Include this sample in the collection.
5. Keep the bottles at room temperature throughout. If collecting for protein or metanephrins, keep them refrigerated.
6. If you miss a void, discard the entire collection and start again on another day. An incomplete collection gives a misleading result.

Labelling and returning the sample

Before returning the bottles, make sure each one is clearly labelled with your full name, date of birth, and hospital number, plus the collection start and end date and time. Mislabelled or unlabelled samples will be rejected by the laboratory.

Return the bottles the same day you finish the collection, together with the request form. If your collection is for creatinine clearance, you will also need a blood test for creatinine on the same day — book this in advance.

Tacrolimus is an immunosuppressant medicine used to treat certain types of kidney inflammation (glomerulonephritis), including minimal change disease, membranous nephropathy, focal segmental glomerulosclerosis (FSGS), and Class V lupus nephritis. It works by calming the immune system to reduce inflammation and protein leakage into the urine.

Off-license use

Tacrolimus is not formally licensed in the UK for glomerulonephritis, but it is widely used by kidney specialists based on substantial clinical experience and medical evidence. "Off-license" simply means it is prescribed outside its original approval — this is common in nephrology and does not mean it is experimental or unsafe.

How to take it

• Always use the same brand — Adoport
• Take it at 10am and 10pm, one hour before or two hours after food
• Take it every day without skipping doses

What to avoid

• Grapefruit and grapefruit juice (affects drug levels)
• St John's Wort and other herbal remedies
• Anti-inflammatory painkillers such as ibuprofen
• Some antibiotics (e.g. clarithromycin) and antifungal or epilepsy medicines
• Always check with Dr Lawrence or your pharmacist before starting any new medicine

Blood level monitoring

Regular blood tests are essential to keep tacrolimus at the right level — too low and it will not work; too high and it may affect kidney function. The typical schedule is:

• After approximately 5 doses (first check)
• Weekly until levels are stable
• Monthly once established
• Every 2 months for long-term treatment

The target blood level is 5–8 ng/mL, adjusted based on your response.

How long will treatment last?

Most patients take tacrolimus for around two years, though this varies. The dose is gradually reduced depending on response. Treatment is considered successful if:

• Partial remission: urine protein falls by more than 50%
• Complete remission: urine protein-to-creatinine ratio (uPCR) falls below 50

If there is no meaningful improvement after 3–6 months, treatment will be stopped.

Side effects to be aware of

Common or important side effects include tremor, headache, sleep disturbance, raised blood sugar, high potassium, high blood pressure, hair thinning, and increased susceptibility to infection. There is also a small long-term increase in risk of certain cancers, particularly skin cancer and lymphoma — sun protection is important.

Seek urgent medical attention if you develop: severe headache, confusion or seizures, sudden worsening of kidney function, or extreme tiredness or muscle weakness.

Pregnancy and fertility

Tacrolimus is considered safe in pregnancy and during breastfeeding. Contraception is recommended while being actively treated for kidney disease. Please let Dr Lawrence know if you are planning a pregnancy or are breastfeeding.