MYCOPLASMA PNEUMONIAE

It is responsible for a common form of pneumonia that mainly affects children and young adults between the ages of 5 and 35 years old, even if infections may also occur in the elderly. M. PNEUMONIAE is considered to be responsible for 40% of communityacquiredpneumonia.The M. PNEUMONIAE infection spreads by means of inter-human contact, through small drops ofsuspended saliva. The microorganism attaches to the cilia and microvilli of the bronchial epithelial cells, causing ciliostasis and then desquamation of the epithelium with subsequent inflammation and the formation of exudate. Adhesion occurs through a special protein called cytadhesin or P1. This protein is immunodominant and a strong specific immune response is generated against it.Since the M. PNEUMONIAE symptoms from pneumonia are the same as those of other bacterial or viral pneumonias, it is difficult to determine a clinical diagnosis but it is very important that a differential laboratory diagnosis be made that allows a specific antibiotic therapy to begin right away. Serology plays a fundamental role and the Complement Fixation Test (CFT) and ELISA are the most commonly used methods. An antibody increase of 4 times between acute and convalescent serum in CFT indicates infection by M. PNEUMONIAE. Given however that the symptoms appear in an insidious way and that the incubation period is relatively long, at the time of testing the patients may already have an antibody response hence a significant titre (≥ 1:64) on a single withdrawal suggests that an infection is on-going. On the other hand, the ELISA method highlights the different antibody classes (IgG, IgM, IgA), which can have different clinical meanings: for example, the IgM antibodies are mainly produced during paediatric infections, while the IgA antibodies seem to indicate that an infection is taking place in adults and in the elderly. DIESSE Diagnostica Senese SpA’s convenient Chorus format offers the ELISA and Complement Fixation Test (solid phase composed of purified P1 protein) for a complete and accurate diagnosis of MYCOPLASMA PNEUMONIAE infection.

Methods:

Immunoenzymatic method for the qualitative determination of IgG, IgA and IgM-class antibodies to Mycoplasma pneumoniae in human serum, using a disposable device applied on the Chorus and Chorus TRIO instruments.The test is based on the ELISA principle (Enzyme Linked ImmunoSorbent Assay) which uses the reaction between the antibodies present in the tested sample and the immobilized antigen bound to solid phases.The immunoglobulins bind to the antigen through incubation with diluted human serum.The disposable devices contain all the reagents to perform the test when applied on the Chorus instruments. The result is expressed as an INDEX (ratio between the OD value of the sample and that of the Cut-off) for qualitative tests and in Arbitrary Units (AU/ml) for quantitative tests.