Why are blood tests considered essential before starting immunotherapy?

Blood tests are considered essential because immunotherapy places specific demands on the immune system, liver, and kidneys. Without confirming that these systems are functioning within safe parameters, healthcare professionals cannot fully assess whether it is appropriate to proceed.

Which specific blood tests are needed before immunotherapy in London?

The most commonly requested tests include full blood count, liver function tests, kidney function tests, total IgE, specific IgE panels, CRP or ESR, and sometimes thyroid function.

Can I get pre-immunotherapy blood tests done privately in London?

Yes. Private health screening clinics in London, including The Allergy Clinic, offer blood testing services with flexible appointments and typically faster turnaround times.

How long before immunotherapy should I have baseline blood tests?

Most clinicians recommend that baseline blood tests are completed within four to six weeks prior to starting immunotherapy.

What does a raised total IgE level mean before immunotherapy?

A raised total IgE level can suggest heightened allergic immune activity, but it does not confirm a specific allergy on its own. It provides context when combined with specific IgE results, symptom history, and clinical examination.

Will I need repeat blood tests during immunotherapy?

Yes. Most immunotherapy protocols include periodic blood testing — commonly at three to six months and then annually — to monitor how your body is responding.

Do baseline blood tests diagnose allergies?

Blood tests can identify immunological sensitisation to specific allergens through specific IgE measurement. However, sensitisation does not always equal clinical allergy. Diagnosis requires clinical correlation by an appropriate healthcare professional.

What happens if my baseline blood tests show abnormal results?

If any markers fall outside expected ranges, your treating clinician will assess the significance in the context of your overall health. This may lead to further investigations, a delay in starting immunotherapy, or adjustments to the treatment approach.

Can The Allergy Clinic help me prepare for immunotherapy blood tests?

The Allergy Clinic provides blood testing and screening services that can support your preparation for immunotherapy. We offer testing and reporting — your results can then be shared with your immunotherapy provider.

Preparing for Immunotherapy in London: Why Baseline Blood Tests Are Considered Essential

Published: 17 March 2026 · Reviewed for clinical accuracy · Written for UK patients

If you are considering immunotherapy in London, your healthcare provider will almost certainly require baseline blood tests before immunotherapy as an essential first step. These pre-treatment blood tests help establish a clear picture of your current health status, ensuring that your body is prepared for the immunological demands that therapy places on key organ systems. Without this essential screening, clinicians cannot safely assess whether you are a suitable candidate for treatment.

This article explains the purpose behind essential baseline blood tests, the specific markers typically requested, what your results may indicate, and how proactive health screening in London can support your immunotherapy journey.

What Are Baseline Blood Tests Before Immunotherapy?

Baseline blood tests before immunotherapy are a defined set of laboratory investigations carried out prior to commencing any form of immune-modulating therapy. They provide a reference point — a "health snapshot" — against which future blood results can be compared throughout your treatment course. These tests typically assess organ function, immune status, inflammatory markers, and allergen-specific antibodies.

Practical Insight: Think of baseline blood tests as the foundation check before building work begins. They do not tell you what the finished structure looks like — but they confirm the ground is stable enough to proceed.

Why Are Pre-Immunotherapy Blood Tests Considered Essential?

Immunotherapy works by gradually retraining the immune system's response to specific allergens. Some patients may also be considered for anti-IgE therapy such as omalizumab as part of their treatment pathway. This process places measurable demands on the body — particularly the liver, kidneys, and immune pathways. Without knowing how these systems are functioning beforehand, healthcare professionals cannot:

Identify pre-existing conditions that may affect treatment safety
Establish reference ranges for ongoing monitoring
Detect subclinical inflammation or immune irregularities
Assess allergen-specific IgE levels to help identify sensitisation
Evaluate overall fitness for immunological intervention

In the UK, both NHS allergy centres and private immunotherapy providers follow protocols aligned with British Society for Allergy and Clinical Immunology (BSACI) guidelines, which recommend thorough baseline assessment before commencing allergen immunotherapy.

Practical Insight: Baseline testing is not about finding problems — it is about confirming readiness and creating a personalised reference point that supports safe, well-monitored care.

Which Biomarkers Are Typically Included in Pre-Immunotherapy Screening?

The exact panel may vary depending on your healthcare provider's protocol, the type of immunotherapy planned, and your individual medical history. However, the following biomarkers are commonly requested:

Full Blood Count (FBC)

A full blood count evaluates red blood cells, white blood cells, and platelets. It can highlight potential anaemia, infection, or immune cell abnormalities. Eosinophil counts within the FBC are particularly relevant, as elevated eosinophils may suggest active allergic inflammation.

Liver Function Tests (LFTs)

The liver plays a central role in metabolising substances introduced during immunotherapy. LFTs measure enzymes such as ALT, AST, and ALP, along with bilirubin and albumin levels. Abnormal results may indicate that liver function requires further assessment before proceeding.

Kidney Function Tests (U&Es)

Urea and electrolyte panels assess how well the kidneys are filtering waste. Creatinine and eGFR (estimated glomerular filtration rate) are key markers. Healthy kidney function is important for processing immune responses and clearing metabolic byproducts.

Total IgE

Total immunoglobulin E provides an overall measure of allergic antibody activity. While a raised total IgE does not confirm a specific allergy, it can suggest heightened immune reactivity and may influence how immunotherapy protocols are tailored. Learn more about understanding total IgE vs specific IgE.

Specific IgE Testing

Specific IgE blood tests measure antibodies directed against individual allergens — such as grass pollen, house dust mite, or pet dander. These results can help identify which allergens may be driving your symptoms and whether immunotherapy targeting those allergens may be clinically appropriate. You can explore more about allergy blood testing on our website.

Inflammatory Markers (CRP / ESR)

C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) indicate general inflammation levels. Elevated markers may suggest an active inflammatory process that could complicate immunotherapy initiation.

Thyroid Function Tests (TFTs)

In some cases, thyroid screening is included because thyroid disorders — particularly autoimmune thyroid conditions — can coexist with allergic disease and may influence immune responses during therapy.

Practical Insight: Each of these markers tells part of the story. Together, they create a comprehensive baseline that your healthcare provider can use to monitor changes over time.

Baseline Blood Test Comparison: What Each Marker Assesses

Blood Test	What It Measures	Why It Matters for Immunotherapy
Full Blood Count (FBC)	Red cells, white cells, platelets, eosinophils	May highlight infection, immune cell changes, or active allergic inflammation
Liver Function (LFTs)	Liver enzymes, bilirubin, albumin	Confirms the liver can support metabolic demands of treatment
Kidney Function (U&Es)	Creatinine, urea, eGFR	Assesses filtration capacity for immune byproducts
Total IgE	Overall allergic antibody level	Can suggest general immune reactivity
Specific IgE	Allergen-targeted antibodies	Confirms sensitisation to specific allergens
CRP / ESR	Inflammatory markers	May reveal active inflammation that could affect therapy timing
Thyroid Function (TFTs)	TSH, T3, T4	Identifies autoimmune thyroid overlap that may influence immune responses

Who Should Consider Pre-Immunotherapy Blood Screening?

While baseline blood tests are typically requested by the clinician overseeing your immunotherapy, there are several groups who may benefit from proactive screening:

Individuals referred for immunotherapy by an NHS or private allergy specialist who need results ready for their consultation
People with long-standing allergic rhinitis, asthma, or venom allergy who are exploring immunotherapy as a potential option
Those with existing health conditions such as autoimmune disorders, thyroid disease, or liver concerns who want to understand their current baseline before discussing treatment eligibility
Londoners seeking faster access to blood work without waiting for NHS pathology appointments

Proactive screening does not replace clinical assessment by an appropriate healthcare professional. However, having recent, comprehensive blood results available can support more productive conversations with your allergy specialist.

If you are unsure which tests may be relevant, our team can provide guidance on available health screening options suited to your needs.

Practical Insight: Arriving at an immunotherapy consultation with recent baseline bloods can sometimes help reduce delays and support more efficient clinical decision-making.

How Often Should Baseline Tests Be Repeated?

Your initial baseline tests are carried out before immunotherapy begins. However, monitoring does not stop there. Most immunotherapy protocols involve periodic blood testing throughout the treatment course — which typically lasts three to five years — to track how the body is responding.

The frequency of repeat testing depends on your clinician's protocol, but common intervals include:

Pre-treatment: Full baseline panel
3–6 months into therapy: Repeat FBC, LFTs, kidney function, and specific IgE
Annually: Comprehensive review panel to assess trends
As clinically indicated: If symptoms change or new health concerns arise

Your treating clinician will determine the exact schedule. Having an accessible, convenient location for blood testing in London can make ongoing monitoring significantly easier to manage.

Understanding Your Results: What Baseline Blood Tests May Indicate

It is important to understand that blood test results are not diagnostic on their own. They form part of a broader clinical picture that your healthcare provider interprets alongside your symptoms, medical history, and physical assessment. Understanding how to read your lab report can help you engage more meaningfully with your results.

Elevated eosinophils on FBC — may indicate active allergic inflammation or parasitic infection
Raised total IgE — can suggest heightened allergic reactivity, though it does not confirm a specific allergy
Positive specific IgE to particular allergens — may indicate immunological sensitisation, which can support the rationale for targeted immunotherapy
Abnormal liver or kidney markers — may indicate that further investigation is needed before immunotherapy can safely begin
Elevated CRP or ESR — sometimes highlights an active inflammatory process that could affect treatment timing

All results should be reviewed by an appropriate healthcare professional who can provide personalised medical advice based on your individual circumstances.

Practical Insight: A single raised marker does not necessarily mean something is wrong. Trends over time, combined with clinical context, provide the most meaningful insight.

Accessing Pre-Immunotherapy Blood Tests in London

London offers a range of options for accessing baseline blood tests, from NHS pathology services to private health screening clinics. For many people, the key considerations are speed, convenience, and having results available in time for their immunotherapy consultation.

Private blood testing in London can often be arranged with shorter waiting times and flexible appointment scheduling. At The Allergy Clinic, we provide blood testing and health screening services designed to support individuals preparing for allergy-related healthcare pathways.

Our role is to provide accurate testing and clear reporting — we do not offer immunotherapy treatment, prescriptions, or clinical diagnosis. Your results can be shared with your treating clinician to support their assessment and planning.

NHS vs Private Pre-Immunotherapy Blood Testing in London

Factor	NHS Pathology	Private Screening (e.g., The Allergy Clinic)
Cost	Free at point of access	Fee applies — please check our website for current pricing
Waiting Time	May involve longer waits depending on GP referral	Typically shorter, with flexible booking
Test Selection	Determined by referring clinician	Can be tailored to your requirements
Result Turnaround	Varies by trust	Results typically available within a few working days
Convenience	Dependent on local phlebotomy availability	Central London locations with appointment flexibility
Result Sharing	Via GP or hospital system	Results provided directly; can be shared with your clinician

Both pathways are valid. The best option depends on your timeline, budget, and personal preference.

Frequently Asked Questions

What are baseline blood tests before immunotherapy?: Baseline blood tests before immunotherapy are a set of laboratory investigations carried out before treatment begins. They typically include a full blood count, liver and kidney function tests, total and specific IgE, and inflammatory markers. These results establish a health reference point that clinicians use to assess suitability and monitor progress throughout the immunotherapy course.
Why are blood tests considered essential before starting immunotherapy?: Blood tests are considered essential because immunotherapy places specific demands on the immune system, liver, and kidneys. Without confirming that these systems are functioning within safe parameters, healthcare professionals cannot fully assess whether it is appropriate to proceed. Baseline results also provide comparison data for ongoing monitoring during treatment.
Which specific blood tests are needed before immunotherapy in London?: The most commonly requested tests include full blood count, liver function tests, kidney function tests, total IgE, specific IgE panels, CRP or ESR, and sometimes thyroid function. Your treating clinician will confirm the exact panel based on your individual health history and the type of immunotherapy planned.
Can I get pre-immunotherapy blood tests done privately in London?: Yes. Private health screening clinics in London, including The Allergy Clinic, offer blood testing services that can be arranged with flexible appointments and typically faster turnaround times. Results can be shared with your immunotherapy provider to support their clinical assessment.
How long before immunotherapy should I have baseline blood tests?: Most clinicians recommend that baseline blood tests are completed within four to six weeks prior to starting immunotherapy. This ensures results are recent enough to reflect your current health status. Your treating healthcare professional will advise on the optimal timing for your specific situation.
What does a raised total IgE level mean before immunotherapy?: A raised total IgE level can suggest heightened allergic immune activity, but it does not confirm a specific allergy on its own. It provides context for your clinician when combined with specific IgE results, symptom history, and clinical examination. It is one piece of the broader assessment picture.
Will I need repeat blood tests during immunotherapy?: Yes. Most immunotherapy protocols include periodic blood testing — commonly at three to six months and then annually — to monitor how your body is responding. Your clinician will determine the schedule based on your treatment plan and any emerging clinical needs.
Do baseline blood tests diagnose allergies?: Blood tests can identify immunological sensitisation to specific allergens through specific IgE measurement. However, sensitisation does not always equal clinical allergy. Diagnosis requires clinical correlation by an appropriate healthcare professional who considers your symptoms, history, and test results together.
What happens if my baseline blood tests show abnormal results?: If any markers fall outside expected ranges, your treating clinician will assess the significance in the context of your overall health. This may lead to further investigations, a delay in starting immunotherapy, or adjustments to the treatment approach. It is a safety measure, not a cause for alarm.
Can The Allergy Clinic help me prepare for immunotherapy blood tests?: The Allergy Clinic provides blood testing and screening services that can support your preparation for immunotherapy. We offer testing and reporting — your results can then be shared with your immunotherapy provider. We do not offer immunotherapy treatment, prescriptions, or clinical diagnosis.

Supporting Your Immunotherapy Journey with Confidence

Preparing for immunotherapy is a meaningful step towards managing allergic conditions more effectively. Baseline blood tests play a critical role in that preparation — providing the clinical foundation upon which safe, well-informed treatment decisions are built.

If you are based in London and would like to arrange pre-immunotherapy blood screening at a time that suits you, The Allergy Clinic is here to help. Our team provides professional testing and clear, accessible reporting to support your healthcare journey.

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Medical Disclaimer

This article is intended for educational and informational purposes only. It does not constitute medical advice, clinical diagnosis, or treatment recommendation. The content provided is designed to support general health awareness and should not be used as a substitute for professional medical guidance.

Individual symptoms, health concerns, or blood test results should always be assessed by an appropriate healthcare professional who can provide personalised advice based on your specific circumstances. The Allergy Clinic provides testing and reporting services only and does not offer diagnosis, treatment, prescriptions, or GP services.

No outcomes are guaranteed, and individual results may vary. If you are experiencing severe or worsening symptoms, please seek urgent medical care or call 999/112.