Campylobacter jejuni and Postinfectious Autoimmune Diseases: A Proof of Concept in Glycobiology

Evolving understanding of Guillain-Barré syndrome pathophysiology and the central role of the classical complement pathway in axonal injury

Guillain-Barré syndrome (GBS) is a rare, frequently postinfectious neuromuscular emergency and the leading cause of acute paralytic neuropathy worldwide. GBS incidence varies considerably across geographic regions, owing predominantly to different infectious exposures. In GBS, antecedent infection leads to production of immunoglobulin G and immunoglobulin M antibodies that cross-react with the myelin sheath and axons of peripheral nerves. These antibodies activate the classical complement pathway, which plays a key role in peripheral nerve injury regardless of autoantibody binding to myelin or axons as a target. The heterogeneous clinical presentation and progression of GBS symptoms have long been attributed to binary axonal and demyelinating neurophysiologic classifications; however, evolving evidence indicates that these pathophysiologic processes overlap. Intravenous immunoglobulin and plasma exchange, the current standard-of-care therapies in GBS, both reduce autoantibody levels and complement activation, thereby aiming to address this convergence of pathophysiology. However, these therapies only partially decrease antibody levels and complement activity and require extended courses of treatment (5 days for intravenous immunoglobulin and 7-14 days for plasma exchange), limiting their effectiveness in addressing acute neuronal damage during the active phase of disease. Given its evolutionary role in antibody binding and activating the classical complement pathway, the complement component C1q has been proposed as a therapeutic target in GBS. The clinical trial program of the C1q inhibitor ANX005, including placebo-controlled, double-blind phase 1b and phase 3 trials in GBS, provides insight into the pathophysiology of GBS and the efficacy of C1q inhibition regardless of neurophysiologic classification or geographic location.

Evaluation of a rapid fluorescence immunoassay for detecting Campylobacter antigens in stool samples

BACKGROUND

The species most frequently causing campylobacteriosis are Campylobacter jejuni and Campylobacter coli, followed by Campylobacter fetus, Campylobacter upsaliensis, and Campylobacter lari. Although polymerase chain reaction (PCR) can be used to detect Campylobacter DNA in stool samples, PCR assays are often validated for C. jejuni and C. coli only, and coproculture results can take several days to receive. For laboratories that do not have access to PCR technology, rapid antigen tests can be of the utmost importance for early diagnosis of the disease. We evaluated the performance of the Sofia Campylobacter Fluorescence Immunoassay (SCFIA) for rapid detection of Campylobacter antigens in stool.

METHODS

In total, 94 frozen and 205 fresh stool specimens were included in retrospective and prospective evaluations, respectively. The linearity of the assay and its limit of detection for different Campylobacter species was evaluated using serial dilutions. Cross reactivity to phylogenetically related species was also investigated. The PCR results from the BD MAX Enteric Panel were considered the gold standard.

RESULTS

The sensitivity of the SCFIA was 97.87% and 96.88% in retrospective and prospective evaluations, respectively. The specificity was 98.84%. The assay exhibited high linearity in serial dilutions for C. coli, C. jejuni, C. armoricus, C. ornithocola, C. lari, and C. upsaliensis, with correlation coefficients of 0.991-0.999, whereas C. fetus was not detected. No cross-reactivity was detected for Aliarcobacter butzleri, Helicobacter cinaedi, or Helicobacter pullorum. The minimum concentration for a positive result at the assay-specific cut-off was 4-17 million CFU/mL. The limit of detection ranged from 106 to 107 CFU/mL.

CONCLUSION

SCFIA results are highly correlated with PCR results, with no cross-reactivity with phylogenetically related species. The linear correlation between fluorescence and CFU/mL results was strong. The assay's ability to detect antigens of various Campylobacter species can aid early diagnosis. However, the inability to detect C. fetus must be considered.

Hemophagocytic lymphohistiocytosis and myopericarditis induced by campylobacter: a case report

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) is a severe disorder characterized by excessive activation of the immune system, leading to hypercytokinemia and damage to multiple organs. We report a rare case of HLH with myopericarditis caused by Campylobacter infection.

CASE PRESENTATION

A 28-year-old male patient with a history of hypertension without medicine control presented at the hospital after a four-day fever, decreasing urine amount, rashes on his trunk and limbs, and other symptoms. He was admitted with a provisional diagnosis of atypical infection and allergic skin rash related to diclofenac. However, his condition deteriorated, and he developed shock, tachycardia, chest distress, and bilateral pleural effusion after admission. Further investigations revealed cardiogenic shock related to myopericarditis, and he was transferred to the ICU. In addition, a stool PCR panel subsequently revealed a positive result for Campylobacter. On day 6, he was diagnosed with HLH. Under Clarithromycin and dexamethasone infusion, leukocytosis, anemia and thrombocytopenia with cardiogenic shock status improved. Then, he was later discharged in stable condition.

CONCLUSIONS

HLH and myopericarditis caused by Campylobacter are very rare. Early detection of Campylobacter-induced HLH and multiple organ failure, as well as prompt use of antibiotics and immunosuppressants, can be helpful for prognosis.

Triggers of Guillain-Barré Syndrome: Campylobacter jejuni Predominates

Guillain-Barré syndrome (GBS) is a rare immune-mediated acute polyradiculo-neuropathy that typically develops after a previous gastrointestinal or respiratory infection. This narrative overview aims to summarise and discuss current knowledge and previous evidence regarding triggers and pathophysiology of GBS. A systematic search of the literature was carried out using suitable search terms. The most common subtypes of GBS are acute inflammatory demyelinating polyneuropathy (AIDP) and acute motor axonal neuropathy (AMAN). The most common triggers of GBS, in three quarters of cases, are previous infections. The most common infectious agents that cause GBS include Campylobacter jejuni (C. jejuni), Mycoplasma pneumoniae, and cytomegalovirus. C. jejuni is responsible for about a third of GBS cases. GBS due to C. jejuni is usually more severe than that due to other causes. Clinical presentation of GBS is highly dependent on the structure of pathogenic lipo-oligosaccharides (LOS) that trigger the innate immune system via Toll-like-receptor (TLR)-4 signalling. AIDP is due to demyelination, whereas in AMAN, structures of the axolemma are affected in the nodal or inter-nodal space. In conclusion, GBS is a neuro-immunological disorder caused by autoantibodies against components of the myelin sheath or axolemma. Molecular mimicry between surface structures of pathogens and components of myelin or the axon is one scenario that may explain the pathophysiology of GBS.

Patient-related healthcare costs for diarrhoea, Guillain Barré syndrome and invasive non-typhoidal salmonellosis in Gondar, Ethiopia, 2020

Background

Globally, foodborne diseases result in a significant disease burden with low- and middle-income countries disproportionately affected. Estimates of healthcare costs related to foodborne disease can aid decision makers to take action to mitigate risks and prevent illness. However, only limited data on the African continent are available, especially related to more severe sequelae. We provide estimates of direct and indirect (non)-medical costs of patients with diarrhoea, Guillain-Barré syndrome (GBS), and invasive non-typhoidal salmonellosis (iNTS) in three healthcare facilities in Gondar, Ethiopia.

Methods

We used healthcare data from patient records, interviews with family caregivers and 2020 healthcare resource unit costs. Descriptive statistical analysis was performed. For diarrhoea, differences in mean and median transformed costs between healthcare facilities and etiologies (Campylobacter spp., enterotoxigenic Escherichia coli, non-typhoidal Salmonella enterica) were analysed with ANOVA and chi squared tests. Contribution of healthcare facility, dehydration severity, sex, age and living area to transformed costs was identified with linear regression. Results are in 2020 USD per patient. To extrapolate to national level, 2017 national incidence estimates were used.

Results

Mean direct medical costs were 8.96 USD for diarrhoea (health centre 6.50 USD, specialised hospital 9.53 USD, private clinic 10.56 USD), 267.70 USD for GBS, and 47.79 USD for iNTS. Differences in costs between diarrhoea patients were mainly associated with healthcare facility. Most costs did not differ between etiologies. Total costs of a diarrhoea patient in the specialised hospital were 67 USD, or 8% of gross national income per capita. For direct medical plus transport costs of a GBS and iNTS patient in the specialised hospital, this was 33% and 8%, respectively. Of the 83.9 million USD estimated national non-typhoidal Salmonella enterica related cost, 12.2% was due to iNTS, and of 187.8 million USD related to Campylobacter spp., 0.2% was due to GBS.

Conclusion

Direct medical costs per patient due to GBS and iNTS were 30 respectively five times those due to diarrhoea. Costs of a patient with diarrhoea, GBS or iNTS can be a substantial part of a household’s income. More severe sequalae can add substantially to cost-of-illness of foodborne hazards causing diarrheal disease.