Personal
Professional
Research
Personal Professional Research Sign Up Login Pro Login
Research C1 Esterase Inhibitor, Serum
Immune System

C1 Esterase Inhibitor, Serum

Optimal Result: 21 - 39 mg/dL.

Measurement of the C1 esterase inhibitor (the first component of the complement) is used to diagnose hereditary angioedema and to monitor levels of the inhibitor during treatment.

What is hereditary angioedema?

Hereditary angioedema is a disorder characterized by recurrent episodes of severe swelling (= angioedema). The most common areas of the body to develop swelling are the limbs, face, intestinal tract, and airway. Minor trauma or stress may trigger an attack, but swelling often occurs without a known trigger. Episodes involving the intestinal tract cause severe abdominal pain, nausea, and vomiting. Swelling in the airway can restrict breathing and lead to life-threatening obstruction of the airway. About one-third of people with this condition develop a non-itchy rash called erythema marginatum during an attack.

Symptoms of hereditary angioedema typically begin in childhood and worsen during puberty. On average, untreated individuals have an attack every 1 to 2 weeks, and most episodes last for about 3 to 4 days. The frequency and duration of attacks vary greatly among people with hereditary angioedema, even among people in the same family.

There are three types of hereditary angioedema, called types I, II, and III, which can be distinguished by their underlying causes and levels of a protein called C1 inhibitor in the blood. The different types have similar signs and symptoms. Type III was originally thought to occur only in women, but families with affected males have been identified.

The most common form (85% of cases) of hereditary angioedema is due to an absolute decrease in the amount of C1 esterase inhibitor. A less common form (15% of cases) is due to the functional abnormality of the inhibitor where levels may be normal. Both abnormalities need to be tested because of the potentially life-threatening nature of the disease.

In addition to the decreased serum esterase C1 inhibitor in patients with hereditary angioedema, there is still a unique quinine polypeptide at elevated concentration during the edema crisis. Patients with episodes of hereditary angioedema also have a low total complement and C4 and C2 components of the complement. Hereditary angioedema is transmitted in an autosomal dominant manner. Heterozygotes also have reduced levels of the C1 esterase inhibitor. During acute attacks of the disease, complement components of C4 and C2 may be significantly reduced, but C1 and C3 components are normal. The factors that promote the onset of angioedema attacks are often unknown.

Notes:

- Angioedema can also occur as an acquired disease. The acquired form includes non-hereditary C1 esterase deficiency and may be caused by medications, allergies, idiopathic forms, angioedema associated with autoimmune disease especially with systemic lupus erythematosus and hypereosinophilia, angioedema occasionally associated with malignancy, and angioedema caused by natural stimuli.

- Abnormally low results are consistent with a heterozygous C1 esterase inhibitor deficiency and hereditary angioedema.

- Fifteen percent of hereditary angioedema patients have a normal or elevated level but nonfunctional C1 esterase inhibitor protein. Detection of these patients requires a functional measurement of C1 esterase inhibitor; FC1EQ / C1 Esterase Inhibitor, Functional Assay, Serum.

- Measurement of C1q antigen levels; C1Q / Complement C1q, Serum, is key to the differential diagnoses of acquired or hereditary angioedema. Those patients with the hereditary form of the disease will have normal levels of C1q, while those with the acquired form of the disease will have low levels.

- Studies in children show that adult levels of C1 inhibitor are reached by 6 months of age.

References:

Atkinson JP, Du Clos TW, Mold C, Kulkarni H, Hourcade D, Wu X. The human complement system: basic concepts and clinical relevance. In: Rich RR, Fleisher TA, Shearer WT, Schroeder HW, Frew AJ, Weyand CM, eds. Clinical Immunology: Principles and Practice. 5th ed. Philadelphia, PA: Elsevier; 2019:chap 21.

Cicardi M, Aberer W, Banerji A, et al. Classification, diagnosis, and approach to treatment for angioedema: consensus report from the Hereditary Angioedema International Working Group. Allergy. 2014;69(5):602-616. PMID: 24673465 www.ncbi.nlm.nih.gov/pubmed/24673465/.

Leslie TA, Greaves MW. Hereditary angioedema. In: Lebwohl MG, Heymann WR, Berth-Jones J, Coulson IH, eds. Treatment of Skin Disease: Comprehensive Therapeutic Strategies. 5th ed. Philadelphia, PA: Elsevier; 2018:chap 101.

Zanichelli A, Azin GM, Wu MA, et al. Diagnosis, course, and management of angioedema in patients with acquired C1-inhibitor deficiency. J Allergy Clin Immunol Pract. 2017;5(5):1307-1313. PMID: 28284781 www.ncbi.nlm.nih.gov/pubmed/28284781/.

Frank MM: Complement deficiencies. Pediatr Clin North Am. 2000;47(6):1339-1354

Gelfand JA, Boss GR, Conley CL, et al: Acquired C1 esterase inhibitor deficiency and angioedema: a review. Medicine. 1979;58(4):321-328

Rosen FS, Alper CA, Pensky J, et al: Genetically determined heterogeneity of the C1 esterase inhibitor in patients with hereditary angioneurotic edema. J Clin Invest. 1971;50(10):2143-2149

Frigas E: Angioedema with acquired deficiency of the C1 inhibitor: a constellation of syndromes. Mayo Clin Proc. 1989;64:1269-1275

Soldin SJ, Hicks JM, Bailey J, et al: Pediatric reference ranges for estradiol and C1 esterase inhibitor. Clin Chem. 1998;44(6s):A17

What does it mean if your C1 Esterase Inhibitor, Serum result is too high?

C1 esterase inhibitor (C1-INH) is a protein found in the fluid part of your blood. It controls a protein called C1, which is part of the complement system.

The complement system is a group of nearly 60 proteins in blood plasma or on the surface of some cells. The complement proteins work with your immune system to protect the body from infections. They also help remove dead cells and foreign material. There are nine major complement proteins. They are labeled C1 through C9. Rarely, people may inherit deficiency of some complement proteins. These people are prone to certain infections or autoimmune disorders.

What does it mean if your C1 Esterase Inhibitor, Serum result is too low?

Low levels of C1-INH may cause certain types of angioedema. Angioedema results in sudden swelling of the tissues of the face, upper throat and tongue. It may also cause difficulty breathing. Swelling in the intestine and abdominal pain may also occur. There are two types of angioedema that result from decreased levels of C1-INH. Hereditary angioedema affects children and young adults under age 20. Acquired angioedema is seen in adults older than age 40. Adults with acquired angioedema are much more likely to also have other conditions, such as such as cancer or autoimmune disease.

Frequently asked questions

Healthmatters is a highly-personalized health dashboard.

Instead of searching for your lab results in different places or tracking them down from different providers, Healthmatters houses, organizes, and interprets them all in one central location.

With a Healthmatters account, you can dive into the details of each biomarker and gain insights into the meaning behind your medical test data, anytime, anywhere.

For our professional users, Healthmatters provides intuitive tools that not only streamline analysis but also save valuable time when delving into your client's lab report history.

Healthmatters.io personal account provides in-depth research on 4000+ biomarkers, including information and suggestions for test panels such as, but not limited to:

  • The GI Effects® Comprehensive Stool Profile,
  • GI-MAP,
  • The NutrEval FMV®,
  • The ION Profile,
  • Amino Acids Profile,
  • Dried Urine Test for Comprehensive Hormones (DUTCH),
  • Organic Acids Test,
  • Organix Comprehensive Profile,
  • Toxic Metals,
  • Complete Blood Count (CBC),
  • Metabolic panel,
  • Thyroid panel,
  • Lipid Panel,
  • Urinalysis,
  • And many, many more.

You can combine all test reports inside your Healthmatters account and keep them in one place. It gives you an excellent overview of all your health data. Once you retest, you can add new results and compare them.

If you are still determining whether Healthmatters support your lab results, the rule is that if you can test it, you can upload it to Healthmatters.

While we work with many popular labs, we welcome reports from lots of other places too.

It's as simple as this: if you can get a test done, you can upload it to Healthmatters and we can interpret results from any lab out there. If laboratories can analyze it, we can interpret it.

If you’re on the hunt for a specific biomarker, contact us and we'll add it to our database. Anything from blood, urine, saliva, or stool can be uploaded, understood, and tracked with your Healthmatters account.

There are two ways to add your test reports to your Healthmatters account. One option is to input the data using the data entry forms. The other method is to utilize our "Data entry service."

Our data entry forms offer an easy, fast, and free way for you to input the reports yourself. Self-entry allows you to add an unlimited number of reports at no cost. We make the self-entry process user-friendly, providing dozens of templates that pre-populate the most popular laboratory panels and offering instant feedback on entered values.

For those who prefer assistance, we offer a "Data entry service" to help you input your data. Simply attach an image or file of your lab test results, and a qualified team member from our data entry team will add the results for you.

We support various file types, including PDFs, JPGs, or Excel. This service is particularly useful if you have many reports to upload or if you're too busy to handle the data entry yourself.

Our special data entry service makes it easy to add your results to your private dashboard. Just attach an image or a file of your lab test results, and our skilled data entry team will do the work for you. It's all done by humans, ensuring that your data is entered accurately and with personal care for each client.

Depending on your account, the data entry service can be included for free or come at an additional cost of $15 per report.

For users on the Complete monthly plan, the first report is entered free of charge, and each additional report incurs a fee of $15.

Unlimited account holders enjoy the entry of ten reports without charge. Subsequent reports are subject to a $15 fee per report.

Additionally, users on the Complete plan can upgrade to a yearly subscription from the account settings. The annual subscription includes a data entry service for five reports.

The Unlimited plan is a one-time purchase for $250, and it covers your account for a lifetime with no additional payments.

For the Complete plan, the cost is $15 per month. You have the flexibility to cancel it anytime through your account settings, ensuring no further payments. To avoid charges, remember to cancel at least a day before the renewal date. Once canceled, the subscription remains active until the end of the current billing cycle.

Additionally, you can upgrade to the yearly Advanced plan from within your account. The annual cost is $79, and it comes with a data entry service for five reports.

You can always upgrade to a lifetime version with a prorated price from a monthly or yearly subscription.

Simply log in and navigate to your account settings to cancel your subscription. Scroll down to locate the 'Cancel' button at the bottom of the page. Ensure you cancel at least one day before the renewal date to prevent any charges. Once cancellation is requested, the subscription remains active until the conclusion of the current billing cycle.

Our goal has been to make your Healthmatters account as intuitive as possible.

We’ve crafted multiple ways for you to navigate your data, whether you're glancing at a single report or delving into your historical test reports.

1. Graph View:

Dive into a visual journey with our biomarker graphs, showcasing over 40 data points. Combining years of results unveils trends, empowering you to make informed decisions. Our visualization tools make it a breeze to compare and understand changes over time, even if your results are from different labs. A search function and filters simplify the exploration of extensive data, allowing you to focus on what needs attention.

2. All Tests View

Explore neatly organized reports on a timeline, highlighting crucial details like dates, critical results, and lab/panel names. Each report opens up to reveal in-depth descriptions and additional recommendations for each biomarker. The history of previous results is just a click away, and you can download a comprehensive report for deeper insights. Color-coded and user-friendly, it's designed for easy reading, understanding, and navigation.

3. Table View:

For a holistic view of all biomarkers side by side, our table view is your go-to. Results are neatly displayed in a categorized and dated table, ideal for those with an extensive test history. Utilize sorting, filters, and color-coding to enhance your analysis and gain extra insights.

Yes, you can download information from your account. We can compile your labs into a CSV file. To download all your labs, you can go to Account Settings, and at the bottom of the page, you will find a link to download your information.

Yes, you can print your report. To do so, navigate to "All tests" and open the report you wish to print. You'll find a print button in the right corner of the report. Click on it, and your browser's print window will open. If you prefer to print in a bigger typeface, adjust the scale using the print window settings.

Yes, you can! We highly recommend activating Two-Factor Authentication (2FA) for your account. To do so, please navigate to the "Profile and Security" section of your account, where you will find instructions for activating 2FA.

Yes, you can. When entering values for the biomarker, you will see an "Edit Range" button. Click this button, and you'll have the option to enter a custom range.

A personal account is all about keeping your own lab test results in check. It's just for you and your personal use.

The professional account is designed for health professionals who wish to track and organize their clients' laboratory results.

To learn more about Healthmatters Pro, please refer to the professional page.

Use promo code to save 10% off any plan.


We implement proven measures to keep your data safe.

At HealthMatters, we're committed to maintaining the security and confidentiality of your personal information. We've put industry-leading security standards in place to help protect against the loss, misuse, or alteration of the information under our control. We use procedural, physical, and electronic security methods designed to prevent unauthorized people from getting access to this information. Our internal code of conduct adds additional privacy protection. All data is backed up multiple times a day and encrypted using SSL certificates. See our Privacy Policy for more details.

Navigate to Immune System

Popular search

14.3.3 ETA PROTEIN, Acetylcholine Receptor (AChR) Antibody, Activated partial thromboplastin time (APTT), Alpha 2-Macroglobulins, Qn, Alpha Melanocyte Stimulating Hormone, ANA SCREEN A, ANA SCREEN B, ANA SCREEN, IFA, ANA Screen, IFA (Positive, Negative), ANA titer, Anti-C1Q Ab, IgG (RDL), Anti-DBL-Strand DNA Ab, Anti-dsDNA (Double-stranded) Ab by Farr method (RDL), Anti-dsDNA ab (Farr Assay), Anti-IgE, ANTI-RNP (CU), Anti-Smith Antibody, Anticardiolipin Ab, IgM, Anticardiolipin Ab,IgA,Qn, Anticardiolipin Ab,IgG,Qn, Antinuclear Ab, HEp-2 Substrate, S, Antinuclear Antibodies (ANA) Screen, Reflex ANA IFA dsDNA Antibodies, Antinuclear Antibodies Direct (ANA Direct), Antiphosphatidylserine IgA, Antiphosphatidylserine IgG, Antiphosphatidylserine IgM, Antithrombin Activity (ATIII), Antithrombin III activity, Baski sleepy, C1 Esterase Inhibitor, Func, C1 Esterase Inhibitor, Serum, C3A Desarg Fragment, C4a Level by RIA, CARDIOLIPIN AB (IGA), CARDIOLIPIN AB (IGG), CARDIOLIPIN AB (IGM), Carnitine Esters, Carnitine, Free, Carnitine, Total, CCP Antibodies IgG/IgA, Centromere, Chromatin, Coccidioides Ab by CF, Coccidioides Ab, IgG, EIA, Coccidioides Ab, IgM, EIA, Complement C1q, Quantitative, Complement C3, Complement C3a, Complement C4, Serum, Complement C4a, Complement Component C1Q, Complement, Total (CH50), Complement, Total (CH50), Quest Diagnostics, Cyclic Citrullinated Peptide Antibody, Cysticercosis (Taenia solium), Dilute Russell's viper venom time (dRVVT), Diphtheria Antitoxoid Antibody, DNA AB Double Stranded Titer, DNA Double-Stranded Ab, IgG, dRVVT Confirm, DRVVT SCREEN, dRVVT Screen Ratio, ds-DNA Antibody, IgG, dsDNA, ENA to Smith (Sm) Antibody, ENA-6 Reflexed, Eosinophil Cationic Protein (ECP), Epidermal Growth Factor (EGF), Erythrocyte Sedimentation Rate (ESR), Esterified/Free Ratio, F004-IgE Wheat, Free Kappa Lt Chains, Serum, Free Lambda Lt Chains, Serum, Ganglioside Antibodies - GM1 (IgG), Ganglioside Antibodies - GM1 (IgM), Ganglioside Antibodies - GQ1b (IgG), Gastrin, GlycA, Helicobacter pylori Abs, Serum, Hemoglobin A2 (Quant), Hexagonal Phase Phospholipid, HISTAMINE RELEASE (CHRONIC URTICARIA), Histamine, Plasma, Histamine, Whole Blood, Histone, HLA-B27 (Human Leukocyte Antigen B27), Human Transforming Growth Factor Beta 1 (TGF-b1), IGE ANTIBODY (ANTI IGE IGG), Immature Grans (Abs), Immature Granulocytes (%), Immunofixation Result, Serum, Immunoglobulin A, Qn, Serum, Immunoglobulin D, Quant, Serum, immunoglobulin E, Immunoglobulin E, Total, Immunoglobulin G, Qn, Serum, Immunoglobulin M, Qn, Serum, INFg, Influenza Type A Antibody Serum, Influenza Type B Antibody Serum, Interleukin-2, Serum, Interleukin-6, Jo 1 Antibodies, IgG, Serum, JO-1, Kappa/Lambda Ratio, Serum, Liver Kidney Mic IgG, Liver-Kidney Microsomal Antibodies, Lupus Anticoagulant, Lysozyme, Serum, Mannose Binding Lectin (MBL), Measles Antibodies, IgG, Monocyte Chemotactic Protein-1 (MCP-1), Mumps Abs, IgG, PEP A2Glob, PHOSPHATIDYLETHANOLAMINE AB (IGA), PHOSPHATIDYLETHANOLAMINE AB (IGG), PHOSPHATIDYLETHANOLAMINE AB (IGM), PHOSPHATIDYLSERINE AB (IGA), PHOSPHATIDYLSERINE AB (IGG), PHOSPHATIDYLSERINE AB (IGM), Plasminogen Activator Inhibitor (PAI-1) AG, Procalcitonin, Prothrombin Fragment 1.2, Prothrombin Time (PT), Prothrombin Time (PT) INR, QUANTIFERON® -TB GOLD PLUS, 1 TUBE, RA Latex Turbid, Reptilase Clotting Time, RF, IgA by EIA (RDL), RF, IgG by EIA (RDL), RF, IgM by EIA (RDL), Rheumatoid factor (RF), Rheumatoid Factor IgA, Rheumatoid Factor IgM, RNA Polymerase III Antibodies, RNP/Sm, Ro-52kD Antibody, Schistosoma IgG, Scl-70, Sed Rate by Modified Westergren, Semi-Quant RF, SICKLE CELL SCRN, Sirolimus, Whole Blood, Sm, SM/RNP Antibody, Smith/RNP (ENA) Ab, IGG, Smooth Muscle Abs, IFA, Ss-B/La Ab Igg, SSA, SSA-52 (Ro52) (ENA) Antibody, IgG, SSA-60 (Ro60) (ENA) Antibody, IgG, SSB, ssDNA, Tacrolimus, Whole Blood, Tetanus Antitoxoid IgG Ab, TGF-b1, Thrombin time, Thrombin-Antithrombin TAT, TNFb, Trans. Growth Fact. beta 1, Transforming Growth Factor beta, Plasma, Tryptase, Tumor Necrosis Factor, Varicella-Zoster Virus (VZV) DNA, Qualitative, Real-Time PCR, VEGF, Plasma, VEGF, Serum, Von Willebrand Factor Antigen (vWF), vWF Activity