Role of immunoglobulin G subclasses in Q fever

• Published in: European journal of clinical microbiology & infectious diseases 1995-12, Vol.14 (12), p.1070-1075
• Main Authors: CAMACHO, M. T, OUTSCHOORN, I, TELLEZ, A
• Format: Article
• Language: English
• Subjects: Acute Disease; Bacterial diseases; Biological and medical sciences; Chronic Disease; Coxiella burnetii - immunology; Disease Progression; Human bacterial diseases; Humans; Immunoglobulin G - immunology; Immunoglobulin gamma-Chains - analysis; Immunoglobulin gamma-Chains - blood; Immunoglobulin gamma-Chains - immunology; Infectious diseases; Medical sciences; Q Fever - diagnosis; Q Fever - immunology; Rickettsial diseases; Tropical bacterial diseases
• ISSN: 0934-9723; 1435-4373
• DOI: 10.1007/BF01590941

The progression of Q fever to either acute or chronic disease has been attributed both to biological characteristics of the bacteria and to the host immune response. In order to determine whether a specific immunoglobulin G (IgG) subclass distribution could play a diagnostic or prognostic role in Q fever, IgG subclass levels were measured in patients with acute or chronic disease. It was observed that (i) IgG1 and IgG3 levels were elevated in patients with chronic Q fever compared to patients with acute disease or normal controls; (ii) variations over time reflected inverse complementary relationships of subclass levels, such as between IgG1 and IgG3 compared with IgG2 and IgG4, or an inverse relationship between IgG1 and IgG2; (iii) variations in IgG2 and IgG3 total subclass levels during follow-up of patients with chronic Q fever showed a decrease in IgG2 with a concomitant increase in IgG3 two years from disease onset. These findings indicate that measurements of IgG subclasses may be a simple, additional tool useful in the diagnosis of Q fever. This data raises the question of an unusual immunoregulatory mechanism in Q fever that is implicated in the presentation of the clinical disease.