The antibodies to islet cell cytoplasm (Islet Cell Antibody, ICA), also called pancreatic insula antibodies are autoantibodies facing antigens of islet cells of the pancreas.
Normal values of antibodies to pancreatic islet or ICA
Normal values for anti-islet cytoplasmic antibodies are normally less than 40 JDF U.
Antibodies to pancreatic islet
These antibodies are called auto antibodies because they are directed towards the organism itself and not towards external antigens such as bacteria or viruses. Their target is the cytoplasm ofpancreatic insula, which is a hormone-producing structure in the pancreas. Cytoplasm is nothing but the liquid and solid contents of the cell.
The pancreatic insula is mainly composed of four different types of cells: among these the most important are the α cells which produce a hormone called glucagon, is the β-producing cells produce insulin.
The antibodies anti pancreatic insula are of class G immunoglobulins (IgG), directed against an intra-cytoplasmic antigen common to all four cell populations of the insula.
The detection of ICA occurs using the indirect immunofluorescence method and are present in 0.5% of the healthy population, in 25% of healthy first degree relatives of patients with IDDM (insulin dependent diabetes), in a fair percentage of pregnant women with gestational diabetes, in the 5-10% of patients with non-insulin-dependent diabetes mellitus (NIDDM), but, above all, they are found in about 85% of cases of IDDM at diagnosis and in about 10% of subjects in the pre-clinical phase (i.e. before the overt symptoms appear) for type I diabetes mellitus.
Over time, their presence in patients with IDDM varies: in 80-90% of cases they disappear within a few weeks while in 10% about of cases remain and, in this case, generally associated with other autoimmune diseases.
If the titration is> 10 JDF they are related to IDDM within 10 years in 41% of cases, while if it is greater than 80 JDF the risk of contracting insulin-dependent diabetes is about 80%.
HAIs have no cytotoxic effect, in fact, diabetic mothers with a positivity for these autoantibodies are not born with diabetic newborns (HAIs are IgG and therefore can cross the placental barrier), cases of negativity for HAIs at the onset of disease and finally no functional anomalies have been reported although it has recently been reported that ICA positive subjects have a loss of the oscillatory rhythm of insulin secretion. What their exact role is is not yet clear; it is possible that they are due to an epiphenomenon of ß-cell damage.
Tags: Laboratory medicine Blood