Tests beginning with the letter I
Laboratory Test Guide: Tests Beginning with the Letters "I" and "İ"
A complete list of all tests performed at Egemed Hospitals’ Medical Laboratories that begin with the letters “I” and “İ” is provided below. To help our patients understand these tests in advance, a brief medical description of each test group and its intended laboratory use are clearly stated.
Immunology, Serology, and Neuroimmunology Tests
IgA
IgD (Serum)
IgE
IgG & IgG (nephélometric)
IgM
Description: These are the blood levels of the essential defense proteins (immunoglobulins) produced by the body’s immune system to fight bacteria, viruses, and allergens.
Purpose: This test is ordered to evaluate congenital or acquired immunodeficiencies, autoimmune diseases, chronic infections, and the severity of allergic reactions (particularly IgE-mediated reactions).
IgG 1, IgG 2, IgG 3, IgG 4
IgG INDEX
Description: These are specific tests that measure four different subtypes of IgG antibodies and compare the rates of IgG production in the blood and cerebrospinal fluid (CSF) (Index).
Purpose: It plays a critical role in the diagnosis of IgG4-related diseases and in the definitive diagnosis of multiple sclerosis (MS) involving the nervous system (increase in the index).
IgLON 5 ANTIBODY
Description: This test measures the level of autoantibodies produced by the immune system against the "IgLON5" protein found on the surface of nerve cells.
Objective: To identify a rare and dangerous form of autoimmune encephalitis in older adults characterized by sleep disorders (such as sleep apnea), difficulty swallowing, and movement disorders.
Biochemistry, Hormone, and Metabolism Tests
IGFBP-3 (Insulin-like Growth Factor-Binding Protein 3)
Description: This protein is the primary carrier of growth hormone in the body and determines how long growth factors remain active in the blood.
Purpose: To evaluate developmental issues and short stature (dwarfism) in children; in adults, it is used to diagnose acromegaly (excessive growth).
INHIBIN B
Description: It is a hormone directly related to reproductive functions, secreted by the ovaries (follicles) in women and by the testes in men.
Purpose: To determine ovarian reserve in women (menopause monitoring) and to monitor certain types of ovarian cancer; and to assess sperm production (spermatogenesis) capacity in men.
INSULIN ANTIBODY
Explanation: These are antibodies that the body mistakenly produces in response to insulin—whether produced by the body itself (endogenous) or administered externally via injection (exogenous).
Objective: To confirm a diagnosis of Type 1 diabetes, investigate the cause of insulin resistance, and identify cases of allergy or resistance to exogenous insulin in patients with diabetes.
IYONIZE Ca (Ionized Calcium)
Description: This test measures the active form of calcium in the blood—the form that is not bound to proteins (albumin), circulates freely, and can be used directly by cells.
Purpose: It is the most sensitive diagnostic method for parathyroid gland disorders, severe renal failure, and critical electrolyte imbalances in intensive care patients.
Prenatal (During Pregnancy) Screening, Hematology, and Allergy Tests
SECOND-TRIMESTER TRIPLE SCREENING TEST
SECOND-TRIMESTER QUAD SCREENING TEST
Description: This test involves analyzing a blood sample taken from the mother between the 16th and 20th weeks of pregnancy to measure the levels of beta-hCG, AFP, and estriol (Triple Screen), as well as inhibin-A (Quadruple Screen), in conjunction with age and weight data.
Purpose: To provide a statistical and medical assessment of the risks of Down syndrome (Trisomy 21), Edwards syndrome (Trisomy 18), and neural tube defects (NTDs) in the fetus.
IMMUNOFIXATION EF (Urine)
IMMUNOFIXATION + Igs
Description: An advanced electrophoresis method used to detect the presence and type (IgG, IgA, IgM, Kappa, Lambda) of abnormal (monoclonal) proteins in blood or urine.
Purpose: This test is used to establish a definitive diagnosis of plasma cell disorders such as multiple myeloma (bone marrow cancer), Waldenström macroglobulinemia, and amyloidosis, and to monitor response to chemotherapy.
COW'S MILK (F2) CLIA
Description: This test measures, with high sensitivity using chemiluminescence (CLIA) technology, the specific IgE antibodies produced by the body’s immune system in response to proteins found in cow’s milk.
Purpose: To confirm the diagnosis of "cow's milk allergy," which underlies symptoms such as skin rashes, diarrhea, or vomiting, particularly in infants and young children.