Evaluation of Pathogenesis and Diagnosis of Mycoplasma Pneumoniae Community-acquired Pneumonia (CAP)

• Enzyme-linked immunospot (ELISpot) assay [Blood] (Diagnostic test), also known as Polymerase chain reaction (PCR) [Pharyngeal swab specimens], Enzyme-linked immunosorbent assay (ELISA) [Serum]: The ASC ELISpot will be developed based on the improved methods recently described \[Nat Protoc 2013;8:1073-87\]. This protocol allows rapid (6-8 h) detection of specific ASCs in small volumes (1-2 ml) of blood. M. pneumoniae protein P1 (50 μl/ml) will be used as antigen. The optimal concentration of coating antigen will be assessed in advance in two-fold serial dilutions for clear spot definition. The M. pneumoniae-specific T cell ELISpot will be developed based on methods recently described \[Nat Protoc 2009;4:461-9\].

Primary outcomes

• Change in numbers of M. pneumoniae-specific ASCs and M. pneumoniae-specific INF-γ-secreting T cells in blood from inclusion (day 0) to 1-month follow-up (day 28) [At day 0 (inclusion, disease presentation) and at day 28 (follow-up, disease resolution)]: Enzyme-linked immunospot (ELISpot) assay and flow cytometry

Secondary outcomes

• Change in M. pneumoniae DNA levels in respiratory samples from inclusion (day 0) to 1-month follow-up (day 28) [At day 0 (inclusion, disease presentation) and at day 28 (follow-up, disease resolution)]: PCR
• Change in total and M. pneumoniae-specific antibody levels (immunoglobulin (Ig)G, IgM, IgA) from inclusion (day 0) to 1-month follow-up (day 28) [At day 0 (inclusion, disease presentation) and at day 28 (follow-up, disease resolution)]: Enzyme-linked immunosorbent assay (ELISA)
• Outcome of community-acquired pneumonia (CAP) assessed by clinical assessment of body temperature (°C) and respiratory rate (per minute) at 1-month follow-up (day 28) [At day 28 (follow-up)]: Clinical assessment of body temperature (°C) and respiratory rate (per minute), with worse outcome defined as body temperature more than 38.5°C and respiratory rate according to age more than 40/min for 3 years, more than 34/min for 4-5 years, more than 30/min for 6-12 years, and more than 16/min for 13-18 years.

Sex: All, ages: 3 Years to any, accepts healthy volunteers

Inclusion Criteria:

CAP cohort:

* Children of age 3 to 18 years;
* In- and outpatients;
* Clinically diagnosed community-acquired pneumonia (CAP);

Healthy control cohort:

\- Healthy asymptomatic children of age 3 to 18 years undergoing an elective surgical procedure;

Family control cohort:

\- Family members of index CAP patients.

Exclusion Criteria:

* Hospital-acquired pneumonia;
* Immunodeficiencies;
* Chronic lung disorders.

• Patrick M. Meyer Sauteur, MD, Principal investigator, University Children's Hospital, Zurich

NIH grants: 2016