High Prevalence of Autoantibodies Against Monomeric C Reactive Protein (CRP) in Children with PFAPA Syndrome

PFAPA syndrome in children

ABSTRACT

Periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome is, as the name implies, characterized by an extremely regular cycle of fevers that is accompanied by one or more other symptoms such as oral ulcers, pharyngitis, adenitis, tonsillitis, sore throat, cervical adenopathy, and headache. Originally known as Marshall syndrome, PFAPA is most commonly identified in children younger than age 5 years; however, adults may also present with the disease, though they may report additional symptoms. PFAPA is now understood to be a diagnosis of exclusion. Laboratory studies are typically unremarkable except for increases in acute phase reactants such as C-reactive protein. Treatment is primarily supportive and most frequently uses systemic steroids to suppress the inflammatory response. Acute flares are self-limited, and the syndrome typically resolves on its own as the child reaches age 7 or 8 years.

C-Reactive Protein: Pathophysiology, Diagnosis, False Test Results and a Novel Diagnostic Algorithm for Clinicians

The current literature provides a body of evidence on C-Reactive Protein (CRP) and its potential role in inflammation. However, most pieces of evidence are sparse and controversial. This critical state-of-the-art monography provides all the crucial data on the potential biochemical properties of the protein, along with further evidence on its potential pathobiology, both for its pentameric and monomeric forms, including information for its ligands as well as the possible function of autoantibodies against the protein. Furthermore, the current evidence on its potential utility as a biomarker of various diseases is presented, of all cardiovascular, respiratory, hepatobiliary, gastrointestinal, pancreatic, renal, gynecological, andrological, dental, oral, otorhinolaryngological, ophthalmological, dermatological, musculoskeletal, neurological, mental, splenic, thyroid conditions, as well as infections, autoimmune-supposed conditions and neoplasms, including other possible factors that have been linked with elevated concentrations of that protein. Moreover, data on molecular diagnostics on CRP are discussed, and possible etiologies of false test results are highlighted. Additionally, this review evaluates all current pieces of evidence on CRP and systemic inflammation, and highlights future goals. Finally, a novel diagnostic algorithm to carefully assess the CRP level for a precise diagnosis of a medical condition is illustrated.

Diagnostic performance of routine blood parameters in periodic fever, aphthous stomatitis, pharyngitis, and adenitis syndrome

BACKGROUND

We aimed to investigate the difference between PFAPA and streptococcal tonsillitis (Strep Pharyngitis) by using blood parameters. We want to evaluate the relationship between periodic fever, aphthous stomatitis, pharyngitis, adenitis (PFAPA) syndrome, and tonsillitis by using NLR.

METHODS

The data of 141 pediatric patients who had applied to our clinic between October 2016 and March 2019 and were diagnosed with PFAPA syndrome and tonsillitis were reviewed from hospital records. The demographic data of the study group were recorded, as were their WBC, neutrophil, and lymphocyte counts, NLR, and MPV values, which are obtained by proportioning these two counts.

RESULTS

CRP and ESR values were significantly higher in the PFAPA group (p = 0.026 and p < 0.001, respectively). No significant difference was determined between the groups in terms of platelet count or lymphocyte count. Receiver operating curve analyses were calculated. The AUC was 0.713 ± 0.04 according to age, and the CRP was 0.607 ± 0.04 (95% confidence interval). Using a cutoff point of >49 months for age, the sensitivity was 0.71 and the specificity was 0.67.

CONCLUSION

With simple laboratory parameters, PFAPA syndrome can be differentiated from a diagnosis of tonsillitis. This may reduce the costs associated with unnecessary antibiotic use. However, these findings still need to be confirmed by other future studies.

PFAPA Syndrome: Clinical, Laboratory and Therapeutic Features in a Single-Centre Cohort

Objective

The aim of this study is to describe a group of Romanian children with periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA) syndrome.

Materials

This consisted of 39 children diagnosed with PFAPA syndrome according to Thomas’ criteria (eight patients with an age at diagnosis <1 year and 31 patients with an age at diagnosis >1 year).

Methods

Retrospective analysis of the patients with PFAPA syndrome was focused on clinical features, laboratory findings and therapeutic methods. Comparison between the two groups divided by age at onset was also investigated.

Results

Median age at onset was 1.58 years, and median age at diagnosis was 2.97 years. The mean interval between episodes was 35.5 days and the mean duration per febrile episode was 4.1 days. The median diagnosis delay was 2.42 years. The patients presented pharyngitis (100%), adenitis (94.8%) and aphthous lesions (66.7%). The frequency of febrile attacks was higher in children with an age at diagnosis under 1 year (p = 0.0287). Younger age was associated with the presence of aphthae. The mean value of C-reactive protein (CRP) was 7.9mg/dl and the mean value of leucocytes was 14,839/mm³. In 95% of patients given oral corticosteroids, remission of symptoms was reported within 24 h. In three patients, tonsillectomy was performed with complete remission of the disease.

Conclusion

We present a cohort of children with PFAPA syndrome, with clinical and laboratory features similar to those described in the literature. Febrile attacks had a higher incidence in children with younger age at the onset of the disease. The patients had a favorable response to corticosteroids.

A Review of Anti-C Reactive Protein Antibodies in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE), the prototype autoimmune disease, is characterized by the production of a plethora of autoantibodies with various roles in the development of disease-related tissue damage. C-reactive protein (CRP) is an acute phase reactant with a pentameric structure. Under acidic or alkaline conditions, or when urea levels are high and/or calcium levels are low, the pentamer (pCRP) dissociates irreversibly into monomeric CRP (mCRP) and exposes new epitopes (neo-CRP). Importantly, anti-mCRP (but not anti-pCRP) antibodies have been described in patients with SLE, their prevalence varying from 4% to 78% in different cohorts. Numerous studies have investigated the relationship between autoantibodies directed against CRP (anti-CRP) and disease activity as well as their association with lupus nephritis (LN), frequently reporting discrepant findings. The main objective of the present review is to describe the role of anti-mCRP antibodies in SLE according to the currently available data.