The Immature Reticulocyte Fraction (IRF) measures the percentage of young red blood cells (RBCs) in the bloodstream, indicating the bone marrow's RBC production rate. High IRF suggests active bone marrow response, as seen in recovery from anemia, while low IRF indicates inadequate marrow activity, common in conditions like aplastic anemia. IRF is essential in diagnosing and monitoring red blood cell disorders, differentiating anemias caused by decreased production versus increased destruction. It's also key in evaluating treatment effectiveness, particularly in patients with chronic kidney disease or undergoing chemotherapy. Its inclusion in advanced hematology analyzers underscores its clinical significance in hematologic condition management.

Immature granulocytes (IGs) are precursor white blood cells that appear in the bloodstream during heightened immune responses, particularly in severe infections or inflammatory conditions. Their presence in a complete blood count (CBC) provides valuable diagnostic information about immune system activity.

Immature granulocytes are white blood cells that are immature. Whenever your body is fighting an infection, it will increase its white blood cell count, and more white blood cells will be immature.

Circulating immature platelets, also known as the immature platelet fraction (IPF), is the term that defines much larger platelets that have been recently released from the bone marrow, presence of which show the thrombopoietic activity of the marrow.

They represent the most recently produced platelets released into the circulation by regenerated BM megakaryocytes. These types of platelets are the analogs of reticulocytes and are similarly large; moreover, they contain elevated amounts of cytoplasmic RNA and decrease in size and RNA content as they age. The number and proportion of immature platelets reflect the rate of thrombopoiesis; the values of these parameters rise and fall concomitantly with the platelet production rate.

The Immature Reticulocyte Fraction (IRF) test is a vital diagnostic tool in the field of hematology, offering crucial insights into the health and functionality of the bone marrow. IRF measures the percentage of immature reticulocytes (young red blood cells) in the blood, providing an early indication of bone marrow response, especially in conditions like anemia. This test is key for diagnosing various types of anemia, assessing bone marrow recovery post-chemotherapy, or monitoring the effectiveness of treatments for conditions affecting red blood cell production.

An immune complex is formed from the binding of an antibody to a soluble antigen. The bound antigen and antibody act as a specific antigen. Immune complexes can be subject to any of a number of responses, which can lead to autoimmune reactivity.

Antibodies Appear: IgA-related renal disease, Mucosal infection, Sjogren’s syndrome

Anti-C1q autoantibodies are indicative for lupus nephritis, but can also be found in other conditions and inflammatory diseases.

Circulating immune complexes can be demonstrated in rheumatic, infectious, and neoplastic diseases, as well as most immunologically mediated illnesses (inflammatory bowel disease, thrombotic thrombocytopenic purpura). Complement is part of the innate immune system. Its major function is recognition and elimination of pathogens. Complement activity plays also an important role in the pathogenesis of systemic autoimmune diseases.

Immunofixation electrophoresis or immunosubtraction capillary electrophoresis identifies the type of immunoglobulin protein(s) present as monoclonal bands on a protein electrophoresis pattern. Typically, this testing determines the presence and type of monoclonal proteins (e.g., IgG kappa).

Immunoglobulin A (IgA), one of the five primary immunoglobulins, plays a pivotal role in mucosal homeostasis in the gastrointestinal, respiratory, and genitourinary tracts, functioning as the dominant antibody of immunity in this role.

Total IgA (Immunoglobulin A), expressed in milligrams per deciliter (mg/dL), is a crucial marker in clinical immunology representing the predominant immunoglobulin class in mucosal secretions and the second most abundant immunoglobulin in serum. This glycoprotein plays a pivotal role in mucosal immunity, offering a primary line of defense against pathogens at mucosal surfaces, including the gastrointestinal, respiratory, and genitourinary tracts. Normal levels of Total IgA in the blood vary based on age and individual health conditions but typically range from 70 to 400 mg/dL in adults.

Immunoglobulin D (IgD) is an antibody isotype that makes up about 1% of proteins in the plasma membranes of immature B-lymphocytes where it is usually coexpressed with another cell surface antibody called IgM.

Remains in the bloodstream to fight bacteria. Functions mainly as an antigen receptor on B cells that have not been exposed to antigens. It has been shown to activate basophils and mast cells to produce antimicrobial factors.

Immunoglobulin E (IgE) is a key antibody in the immune system, crucial for diagnosing and managing allergies. Testing for IgE is important for identifying specific allergens causing allergic reactions, which can range from mild symptoms like sneezing to severe, potentially life-threatening conditions like anaphylaxis. Measuring IgE levels helps in creating personalized treatment plans, including medication and immunotherapy. It's also used to monitor the effectiveness of allergy treatments and assess the severity of chronic conditions like asthma. Elevated IgE levels can indicate broader immune system issues, making it a valuable tool in immunological assessments. With allergies becoming more common, IgE testing is increasingly important in healthcare, aiding in better patient care in allergy and immunology.

Immunoglobulin E (IgE) are antibodies produced by the immune system. 

IgE antibodies are found in the lungs, skin, and mucous membranes. They cause the body to react against foreign substances such as pollen, fungus spores, and animal dander. They are also involved in allergic reactions to milk, some medicines, and some poisons.

In the blood of healthy people, IgE antibodies make up less than 0.001% of all immunoglobulins. These IgE antibodies are key in triggering allergic responses when people sensitive to allergens come into contact with them.

Structurally, IgE resembles other antibodies, having two light chains and two heavy chains. The heavy chains have a special region that determines the antibody's specificity to antigens. Measuring IgE levels is clinically significant mainly because of its role in allergic reactions, even though IgE myeloma is a very rare condition.

The most abundant immunoglobulin in human serum is immunoglobulin G (IgG) (approximately 80% of the total). IgG protein is comprised of molecules of 4 subclasses designated IgG1 through IgG4. Each subclass contains molecules with a structurally unique gamma heavy chain. Of total IgG, approximately 65% is IgG1, 25% is IgG2, 6% is IgG3, and 4% is IgG4. Molecules of different IgG subclasses have somewhat different biologic properties (eg, complement fixing ability and binding to phagocytic cells), which are determined by structural differences in gamma heavy chains. Clinical interest in IgG subclasses concerns potential immunodeficiencies (eg, subclass deficiencies) and IgG4-related diseases (eg, IgG4 elevations). The IgG subclass assay (IGGS / IgG Subclasses, Serum) is best for deficiency testing, and the IgG4 assay (IGGS4 / Immunoglobulin Subclass IgG4, Serum) is best for IgG4-related disease testing.

Immunoglobulin M (IgM), which is found mainly in the blood and lymph fluid, is the first antibody to be made by the body to fight a new infection. Expressed on the surface of B cells (monomer) and in a secreted form (pentamer) with very high avidity (forms multiple binding sites with antigen). Eliminates pathogens in the early stages of B-cell mediated (humoral) immunity before there is sufficient IgG. 

Immunoglobulin M (IgM) is the first antibody produced by the immune system in response to infection, playing a crucial role in early defense against bacteria and viruses. A blood test measuring IgM levels helps doctors evaluate immune health, diagnose immune deficiencies, distinguish between recent and past infections, and investigate autoimmune diseases or certain blood cancers. Elevated IgM may indicate a recent infection, autoimmune disorder, liver disease, or plasma cell cancer, while low IgM can signal immune deficiency, protein loss, or bone marrow problems. Results should always be interpreted alongside other tests and clinical symptoms, as IgM levels alone do not confirm a diagnosis.

IgG immunoglobulins are composed of four subtypes named IgG1, IgG2, IgG3 and IgG4. Each subclass is present in the serum in different concentrations, varies with age, and has different roles for immune response. Abnormal levels of one or more subclasses may be associated with certain conditions.

This marker helps to evaluate sinopulmonary infections, asthma; immunotherapy hyposensitization; and allergies.