Serological evaluation of O fever in humans: enhanced phase I titers of immunoglobulins G and A are diagnostic for Q fever endocarditis

Abstract

Serological parameters were compared in 15 cases of Coxiella burnetii infection comprising 5 cases each of primary Q fever, chronic granulomatous hepatitis, and endocarditis. The diagnosis was made on the basis of clinical history and serology and on the isolation of C. burnetii phase I from biopsy specimens of liver and bone marrow from two patients with granulomatous hepatitis and from the aortic valve vegetations of five patients with endocarditis. The temporal sequences of immunoglobulin levels, rheumatoid factor, and specific antibody responses to phase II and phase I antigens of C. burnetii were evaluated as predictive correlates of the three Q fever entities. Serum levels of immunoglobulin classes G, M, and A were variable in all the entities of Q fever. Increased mean levels (in milligrams per deciliter) of immunoglobulin G (IgG) and IgA were noted with chronic disease in the sera of some patients, whereas IgM levels were not significantly different from normal values. Rheumatoid factor was significantly elevated in chronic disease but not in primary Q fever. The temporal sequence of C. burnetii phase II and phase I antibodies were compared by microagglutination, complement fixation, and indirect microimmunofluorescence tests. All of these serological tests were useful in distinguishing primary from chronic disease. Thus, the ratio of anti-phase II to anti-phase I antibodies was greater than 1, greater than or equal to 1, and less than or equal to 1 for primary Q fever, granulomatous hepatitis, and Q fever endocarditis, respectively. Moreover, the high phase-specific IgA antibody titers in the indirect microimmunofluorescence test were diagnostic for endocarditis.

Serological Evidence that the Q Fever Agent (Coxiella burnetii) Has Spread Widely among Dairy Cattle of Japan

“…All these sera were frozen and transferred to our laboratory within a few days after venipuncture, and were stored at -30 C before examination. The indirect immunofluorescence (IF) test was used to detect antibodies against phase I and phase II antigens of C. burnetii (16). As a screening test, all sera were diluted 40-fold with phosphate-buffered saline containing 0.3% ovalbumin (Sigma Chemicals Co., St. Louis, Mo., U.S.A.).…”

A comparison of methods for extracting DNA from Coxiella burnetii as measured by a duplex qPCR assay

“…In Q-fever infections, C. burnetii may not be circulating in the blood but may be present in other tissues such as bone marrow, as demonstrated in patients with chronic Q fever (Peacock et al 1983) and post-Q-fever fatigue syndrome 5 years after the primary infection (Harris et al 2000) and 12 years following acute infection (Marmion et al 2005). In a previous study, dilutions of the vaccine Q-Vax Ò (containing approximately 1 · 10 9 cells per 25 lg) were made in buffer.…”

“…Previous studies have shown that in chronic Q fever, C. burnetii DNA is present in bone marrow samples (Peacock et al 1983) in which it can persist for up to 12 years after primary infection (Harris et al 2000;Marmion et al 2005). Bone marrow has similar inhibitors as blood with an increased amount of host (eukaryotic) DNA, which is itself inhibitory to PCR (Roussel et al 2005).…”

Comparison of the new InoDiag automated fluorescence multiplexed antigen microarray to the reference technique in the serodiagnosis of atypical bacterial pneumonia

“…Currently, IFA is the reference technique for Q-fever diagnosis [25], and the InoDiag technology described here offers the advantage of IFA with automation. As for acute F. tularensis infection, because of the difficulty of culturing the pathogen, most of the cases are diagnosed on the basis of combined clinical and serological findings.…”