Cytometry profiling of ex vivo recall responses to Coxiella burnetii in previously naturally exposed individuals reveals long-term changes in both adaptive and innate immune cellular compartments

Abstract:

Introduction: Q fever, caused by the intracellular bacterium Coxiella burnetii, is considered an occupational and biodefense hazard and can result in debilitating long-term complications. While natural infection and vaccination induce humoral and cellular immune responses, the exact nature of cellular immune responses to C. burnetii is incompletely understood. The current study seeks to investigate more deeply the nature of long-term cellular recall responses in naturally exposed individuals by both cytokine release assessment and cytometry profiling.

Methods: Individuals exposed during the 2007-2010 Dutch Q fever outbreak were grouped in 2015, based on a C. burnetii-specific IFNγ release assay (IGRA), serological status, and self-reported clinical symptoms during initial infection, into asymptomatic IGRA-negative/seronegative controls, and three IGRA-positive groups (seronegative/asymptomatic; seropositive/asymptomatic and seropositive/symptomatic). Recall responses following in vitro re-stimulation with heat-inactivated C. burnetii in whole blood, were assessed in 2016/2017 by cytokine release assays (n=55) and flow cytometry (n=36), and in blood mononuclear cells by mass cytometry (n=36).

Results: Cytokine release analysis showed significantly elevated IL-2 responses in all seropositive individuals and elevated IL-1β responses in those recovered from symptomatic infection. Comparative flow cytometry analysis revealed significantly increased IFNγ, TNFα and IL-2 recall responses by CD4 T cells and higher IL-6 production by monocytes from symptomatic, IGRA-positive/seropositive individuals compared to controls. Mass cytometry profiling and unsupervised clustering analysis confirmed recall responses in seropositive individuals by two activated CD4 T cell subsets, one characterized by a strong Th1 cytokine profile (IFNγ+IL-2+TNFα+), and identified C. burnetii-specific activation of CD8 T cells in all IGRA-positive groups. Remarkably, increased C. burnetii-specific responses in IGRA-positive individuals were also observed in three innate cell subpopulations: one characterized by an IFNγ+IL-2+TNFα+ Th1 cytokine profile and lack of canonical marker expression, and two IL-1β-, IL-6- and IL-8-producing CD14+ monocyte subsets that could be the drivers of elevated secretion of innate cytokines in pre-exposed individuals.

Discussion: These data highlight that there are long-term increased responses to C. burnetii in both adaptive and innate cellular compartments, the latter being indicative of trained immunity. These findings warrant future studies into the protective role of these innate responses and may inform future Q fever vaccine design.

Source: Raju Paul S, Scholzen A, Reeves PM, Shepard R, Hess JM, Dzeng RK, Korek S, Garritsen A, Poznansky MC, Sluder AE. Cytometry profiling of ex vivo recall responses to Coxiella burnetii in previously naturally exposed individuals reveals long-term changes in both adaptive and innate immune cellular compartments. Front Immunol. 2023 Oct 11;14:1249581. doi: 10.3389/fimmu.2023.1249581. PMID: 37885896; PMCID: PMC10598782. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10598782/ (Full text)

Long-term health outcomes of Q-fever fatigue syndrome patients

Summary:

This study determined long-term health outcomes (≥10 years) of Q-fever fatigue syndrome (QFS). Longterm health complaints, health-related quality of life (HRQL), health status, energy level, fatigue, post exertional malaise, anxiety and depression were assessed. Outcomes and determinants were studied for the total sample and compared among age subgroups: young (<40y), middle-aged (≥40-<65y), and older
(≥65y) patients.

368 QFS patients were included. Participants reported a median number of 12.0 long-term health complaints. Their HRQL (median EQ-5D-5L index: 0.63) and health status (median EQ VAS: 50.0) were low, their level of fatigue was high, and many experienced post-exertional malaise complaints (98.9%). Young and middle-aged patients reported worse health outcomes compared to older patients, with both groups reporting a significantly worse health status, higher fatigue levels and anxiety, and more post-exertional malaise complaints; and middle-aged patients having a lower HRQL and a higher risk of depression.

Multivariate regression analyses confirmed that older age is associated with better outcomes, except for the number of health complaints. QFS has thus a considerable impact on patients’ health more than 10 years after infection. Young and middle-aged patients experience more long-term health consequences compared to older patients. Tailored healthcare is recommended to provide optimal care for each QFS patient.

Source: Spronk, I., Brus, I., Groot, A., Tieleman, P., Olde Loohuis, A., Haagsma, J., & Polinder, S. (2023). Long-term health outcomes of Q-fever fatigue syndrome patients. Epidemiology & Infection, 1-35. doi:10.1017/S0950268823001401 https://www.cambridge.org/core/journals/epidemiology-and-infection/article/longterm-health-outcomes-of-qfever-fatigue-syndrome-patients/99B3D80E172A66619C216506E020BB02 (Full text available as PDF file)

Incidence of chronic Q fever and chronic fatigue syndrome: a six year follow-up of a large Q fever outbreak

Abstract:

Objectives: Acute Q fever is a generally self-limiting infection caused by the intracellular gram-negative bacterium Coxiella (C.) burnetii. For yet unknown reasons, a subset of patients develops chronic a infection. Furthermore, a Chronic Fatigue Syndrome (CFS) as post-acute Q fever sequelae has been described. We here investigated the rates of chronic Q fever and incidences of CFS six years after one of the largest European Q fever outbreaks that occurred in Jena, Germany in 2005 with 331 reported cases, who lived in proximity of a grazing sheep herd.

Methods: A total of 80 patients and 52 non-diseased household members from the former outbreak, were enrolled six years after the outbreak, blood samples collected and tested for a chronic Q fever were determined by seroprevalence using referenced immunofluorescence tests. Also, the presence of a CFS was assessed using the Short Form Symptom Inventory developed by the Centers (United States) for Disease Control and Prevention (SF CDC- SI).

Results: In 80 out of 132 (60.6%) study participants, previous Q fever infection was confirmed serologically, while no previous infection was detected in the 52 household members. None of the participants fulfilled the serological criteria of chronic Q fever. The evaluation of the CDC-SI did not show any differences between the two groups. Also, there was no difference between both groups regarding fulfillment of CFS-defining criteria (n = 3 (3.8 %; sero-positive) vs. n = 2 (3.8 %; sero-negative), p = 0.655).

Conclusion: Our six-year follow-up study of a large Q fever outbreak did not find evidence for chronic Q fever or post Q fever CFS. There was no asymptomatic sero-positivity in household members of Q fever patients.

Source: Ankert J, Frosinski J, Weis S, Boden K, Pletz MW. Incidence of chronic Q fever and chronic fatigue syndrome: a six year follow-up of a large Q fever outbreak. Transbound Emerg Dis. 2021 Jul 9. doi: 10.1111/tbed.14224. Epub ahead of print. PMID: 34240822. https://pubmed.ncbi.nlm.nih.gov/34240822/

Objective Cognitive Performance and Subjective Complaints in Patients With Chronic Q Fever or Q Fever Fatigue Syndrome

Abstract:

Background: Primary aim of this study was to compare cognitive performance of patients with chronic Q fever or Q fever fatigue syndrome (QFS) to matched controls from the general population, while taking performance validity into account. Second, we investigated whether objective cognitive performance was related to subjective cognitive complaints or psychological wellbeing.

Methods: Cognitive functioning was assessed with a neuropsychological test battery measuring the domains of processing speed, episodic memory, working memory and executive functioning. Tests for performance validity and premorbid intelligence were also included. Validated questionnaires were administered to assess self-reported fatigue, depressive symptoms and cognitive complaints.

Results: In total, 30 patients with chronic Q fever, 32 with QFS and 35 controls were included. A high percentage of chronic Q fever patients showed poor performance validity (38%) compared to controls (14%, p = 0.066). After exclusion of participants showing poor performance validity, no significant differences between patients and controls were found in the cognitive domains. QFS patients reported a high level of cognitive complaints compared to controls (41.2 vs 30.4, p = 0.023). Cognitive complaints were not significantly related to cognitive performance in any of the domains for this patient group.

Conclusions: The high level of self-reported cognitive complaints in QFS patients does not indicate cognitive impairment. A large proportion of the chronic Q fever patients showed suboptimal mental effort during neuropsychological assessment. More research into the underlying explanations is needed. Our findings stress the importance of assessing cognitive functioning by neuropsychological examination including performance validity, rather than only measuring subjective cognitive complaints.

Source: Reukers DFM, Aaronson J, van Loenhout JAF, et al. Objective cognitive performance and subjective complaints in patients with chronic Q fever or Q fever fatigue syndrome. BMC Infect Dis. 2020;20(1):397. Published 2020 Jun 5. doi:10.1186/s12879-020-05118-z https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7275429/ (Full text)

 

Cytokine profiles in patients with Q fever fatigue syndrome

Abstract:

Background: Q fever fatigue syndrome (QFS) is a state of prolonged fatigue following around 20% of acute Q fever cases. It is thought that chronic inflammation plays a role in its aetiology. To test this hypothesis we measured circulating cytokines and the exvivo cytokine production in patients with QFS and compared to various control groups.

Materials/methods: Peripheral blood mononuclear cells (PBMCs), whole blood, and serum were collected from 20 QFS patients, 19 chronic fatigue syndrome (CFS) patients, 19 Q fever seropositive controls, and 25 age- and sex-matched healthy controls. Coxiella-specific ex-vivo production of tumor necrosis factor (TNF)α, interleukin (IL)-1β, IL-6, and interferon (IFN) was measured, together with a total of 92 circulating inflammatory proteins.

Results: PBMCs of QFS patients produced more IL-6 (P = 0.0001), TNFα (P = 0.0002), and IL-1β (P = 0.0005) than the various control groups when stimulated with Coxiella antigen. QFS patients had distinct differences in circulating inflammatory markers compared to the other groups, including higher concentrations of circulating IL-6 and IFNγ.

Conclusion: QFS patients showed signs of chronic inflammation compared to asymptomatic Q fever seropositive controls, CFS patients, and healthy controls, of which the monocyte-derived cytokines TNFα, IL-1β, and especially IL-6, are likely crucial components.

Source: Raijmakers, Ruud P.H. et al. Cytokine profiles in patients with Q fever fatigue syndrome. Journal of Infection , Volume 0 , Issue 0 , DOI: https://doi.org/10.1016/j.jinf.2019.01.006

Peripheral blood gene expression in postinfective fatigue syndrome following from three different triggering infections

Abstract:

BACKGROUND: Several infections trigger postinfective fatigue syndromes, which share key illness characteristics with each other and with chronic fatigue syndrome (CFS). Previous cross-sectional case-control studies of CFS have suggested that unique gene expression signatures are evident in peripheral blood samples.

METHODS: Peripheral blood transcriptomes in samples collected longitudinally, in 18 subjects with a fatigue syndrome lasting ≥ 6 months after acute infection due to Epstein-Barr virus, Ross River virus, or Coxiella burnetii (Q fever), and 18 matched control subjects who had recovered promptly, were studied by microarray (n = 127) and confirmatory quantitative polymerase chain reaction (PCR). Gene expression patterns associated with CFS were sought by univariate statistics and regression modeling.

RESULTS: There were 23 genes with modest differential expression (0.6-2.3-fold change) in within-subject comparisons of early, symptomatic time points with late, recovered time points. There were modest differences found in 63 genes, either in cross-sectional comparison of cases and controls at 6 months after infection onset or in the regression model. There were 223 genes significantly correlated with individual symptom domains. Quantitative PCR confirmed 33 (73%) of 45 genes-none were consistent across cohorts.

CONCLUSIONS: Although the illness characteristics of patients with postinfective fatigue syndromes have more similarities than differences, no reliable peripheral blood gene expression correlate is evident.

 

Source: Galbraith S, Cameron B, Li H, Lau D, Vollmer-Conna U, Lloyd AR. Peripheral blood gene expression in postinfective fatigue syndrome following from three different triggering infections. J Infect Dis. 2011 Nov 15;204(10):1632-40. doi: 10.1093/infdis/jir612. Epub 2011 Sep 29. http://jid.oxfordjournals.org/content/204/10/1632.long (Full article)

 

Chronic fatigue syndrome after Q fever

Abstract:

BACKGROUND: Q fever is a common and acute but rare chronic zoonosis caused by Coxiella burnetii. Its acute form manifests as atypical pneumonia, flu-like syndrome, or hepatitis. Some authors observed symptoms of chronic fatigue in a small number of patients after the acute phase of Q fever; in many cases serological assay confirmed the activity of Coxiella burnetii infection. The effect of antibiotic therapy on post-Q-fever fatigue syndrome has not been studied in south-east Europe thus far.

CASE REPORTS: Three patients are presented with post-Q-fever fatigue syndrome. All fulfilled the CDC criteria for chronic fatigue syndrome. IgA antibodies to phase I of the growth cycle of Coxiella burnetii were positive in two patients and negative in one. Two patients were treated with doxycycline for two weeks in the acute phase of illness and one with a combination of erythromycin and gentamycin. After 4-12 months they developed post-Q-fever fatigue syndrome and were treated with intracellular active antibiotics (fluoroquinolones and tetracycline) for 3-12 months. Efficacy of the treatment was observed in two patients, but in one patient the results were not encouraging.

CONCLUSIONS: These results suggest the possibility of the involvement of Coxiella burnetii infection in the evolution of chronic fatigue syndrome. This is the first report on post-Q-fever fatigue syndrome in Mediterranean countries. Evidence of IgA antibodies to phase I of the growth cycle of Coxiella burnetii is not a prerequisite for establishing a diagnosis of CFS. The recommendation of antibiotic treatment in post-Q-fever fatigue syndrome requires further investigation.

 

Source: Ledina D, Bradarić N, Milas I, Ivić I, Brncić N, Kuzmicić N. Chronic fatigue syndrome after Q fever. Med Sci Monit. 2007 Jul;13(7):CS88-92. https://www.ncbi.nlm.nih.gov/pubmed/17599032

 

Treatment of chronic fatigue syndrome with antibiotics: pilot study assessing the involvement of Coxiella burnetii infection

Abstract:

OBJECTIVE: To examine whether Coxiella burnetii (C. burnetii) is involved in chronic fatigue syndrome (CFS), we administered tetracycline antibiotics to subjects with CFS, and followed changes in clinical symptoms, PCR findings, and C. burnetii antibody titers.

PATIENTS AND METHODS: The subjects were 8 patients with CFS and 213 with nonspecific complaints such as chronic fatigue and low-grade fever for several months or longer but not meeting the diagnostic criteria for CFS. All were examined for C. burnetii infection by nested PCR and the indirect immunofluorescence test (IF).

RESULTS: Four CFS patients (the CFS group) and 54 controls [the post-Q fever fatigue syndrome (QFS) group] positive for C. burnetii were treated mainly with minocycline or doxycycline (100 mg/day) for 3 months. After treatment, all 58 patients tested negative for C. burnetii infection. In the CFS group, no significant difference was noted between the mean pre- and post-treatment temperatures or headache scores. Similarly, there was no significant improvement in performance status (PS) scores. In the QFS group, however, mean temperatures and headache scores were significantly decreased after treatment (p<0.001). PS scores were also improved.

CONCLUSION: These results suggest the possibility of direct involvement of C. burnetii in the pathological state of CFS to be low, despite the C. burnetii infection rate being high in CFS patients. This is a pilot study and further larger investigations are necessary to confirm our preliminary results.

 

Source: Iwakami E1, Arashima Y, Kato K, Komiya T, Matsukawa Y, Ikeda T, Arakawa Y, Oshida S. Treatment of chronic fatigue syndrome with antibiotics: pilot study assessing the involvement of Coxiella burnetii infection. Intern Med. 2005 Dec;44(12):1258-63. https://www.ncbi.nlm.nih.gov/pubmed/16415546

 

Diagnostic evaluation of 2′, 5′-oligoadenylate synthetase activities and antibodies against Epstein-Barr virus and Coxiella burnetii in patients with chronic fatigue syndrome in Japan

Abstract:

To investigate the association of viral infections with chronic fatigue syndrome (CFS), we assayed 2′, 5′-oligoadenylate synthetase (2-5AS) activities in peripheral blood mononuclear cells from CFS patients in Japan. These patients were diagnosed in two hospitals, H1 and H2, located in different areas of the country.

The activities were detected in 19 (86%) and 7 (32%) of each of the 22 patients in H1 and H2, respectively, while they were detected in only four (11%) out of the 38 healthy controls. IFN-alpha was similarly detected in a few CFS patients and healthy controls.

We also assayed the antibody titers against Epstein-Barr virus (EBV) and Coxiella burnetii in these patients. The EBV anti-EA-IgG antibodies were detected in two (9%) and seven (32%) of each of the 22 patients in H1 and H2, respectively. Anti-C. burnetii IgG antibodies were detected in six (27%) out of 22 patients in H1 but not in 22 patients in H2, while they were detected in one (11%) of the nine healthy controls.

Some CFS patients may be associated with EBV or C. burnetii infection. There were some statistical correlations between the 2-5AS activities and antibody titers of EA-IgG (P < 0.05, Student’s t-test) but not to the antibody titers of C. burnetii. The up-regulation of 2-5AS activities suggests immunological dysfunctions with some virus infections in the CFS patients. Our results indicate that 2-5AS activities are useful for a diagnostic marker of CFS and for exploring the complicated pathogenesis of CFS.

 

Source: Ikuta K, Yamada T, Shimomura T, Kuratsune H, Kawahara R, Ikawa S, Ohnishi E, Sokawa Y, Fukushi H, Hirai K, Watanabe Y, Kurata T, Kitani T, Sairenji T. Diagnostic evaluation of 2′, 5′-oligoadenylate synthetase activities and antibodies against Epstein-Barr virus and Coxiella burnetii in patients with chronic fatigue syndrome in Japan. Microbes Infect. 2003 Oct;5(12):1096-102. http://www.ncbi.nlm.nih.gov/pubmed/14554250

 

Variation in immune response genes and chronic Q fever. Concepts: preliminary test with post-Q fever fatigue syndrome

Abstract:

Acute primary Q fever is followed by various chronic sequelae. These include subacute Q fever endocarditis, granulomatous reactions in various organs or a prolonged debilitating post-infection fatigue syndrome (QFS). The causative organism, Coxiella burnetii, persists after an initial infection. The differing chronic outcomes may reflect variations within cytokine and accessory immune control genes which affect regulation of the level of persistence. As a preliminary test of the concept we have genotyped QFS patients and controls for gene variants spanning 15 genes and also examined HLA-B and DR frequencies. QFS patients exhibited a significantly increased frequency of HLA-DR-11 compared with controls and also significant differences in allelic variant frequencies within the NRAMP, and IFN gamma genes. These results indicate a possible genetic role in the expression of overt chronic Q fever. Further studies will be undertaken to increase sample sizes, to survey other forms of chronic Q fever and to examine Q fever patients who have recovered without sequelae.

 

Source: Helbig KJ, Heatley SL, Harris RJ, Mullighan CG, Bardy PG, Marmion BP. Variation in immune response genes and chronic Q fever. Concepts: preliminary test with post-Q fever fatigue syndrome. Genes Immun. 2003 Jan;4(1):82-5. http://www.ncbi.nlm.nih.gov/pubmed/12595908