Neither hereditary periodic fever nor periodic fever, aphthae, pharingitis, adenitis: Undifferentiated periodic fever in a tertiary pediatric center

Disease phenotypes in adult patients with suspected undifferentiated autoinflammatory diseases and PFAPA syndrome: Clinical and therapeutic implications

BACKGROUND

Undifferentiated autoinflammatory diseases are characterized by recurrent or persistent fever, usually combined with other inflammatory manifestations, and negative or inconclusive genetic studies for monogenic autoinflammatory disorders.

AIMS

To define and characterize disease phenotypes in adult patients diagnosed in an adult reference center with undifferentiated autoinflammatory diseases, and to analyze the efficacy of the drugs used in order to provide practical diagnostic and therapeutic recommendations.

METHODS

Retrospective study (2015-2022) of patients with undifferentiated autoinflammatory diseases among all patients visited in our reference center. Demographic, clinical, laboratory features and detailed therapeutic information was collected.

RESULTS

Of the 334 patients with a suspected autoinflammatory disease, 134 (40%) patients (61% women) were initially diagnosed with undifferentiated autoinflammatory diseases. Mean age at disease onset and at diagnosis was 28.7 and 37.7 years, respectively. In 90 (67.2%) patients, symptoms started during adulthood. Forty-four (32.8%) patients met diagnostic/classification criteria for adult PFAPA syndrome. In the remaining patients, four additional phenotypes were differentiated according to the predominant manifestations: a) Predominantly fever phenotype (n = 18; 13.4%); b) Predominantly abdominal/pleuritic pain phenotype (n = 9; 6.7%); c) Predominantly pericarditis phenotype (n = 18; 13.4%), and d) Complex syndrome phenotype (n = 45; 33.6%). Prednisone (mainly on demand), colchicine and anakinra were the drugs commonly used. Overall, complete responses were achieved with prednisone in 41.3%, colchicine in 40.2%, and anakinra in 58.3% of patients in whom they were used. By phenotypes, prednisone on demand was more effective in adult PFAPA syndrome and colchicine in patients with the abdominal/pleuritic pain pattern and PFAPA syndrome. Patients with complex syndrome achieved complete responses with prednisone (21.9%), colchicine (25.7%) and anakinra (44.4%), and were the group more often requiring additional immunosuppressive drugs.

CONCLUSIONS

The analysis of the largest single-center series of adult patients with undifferentiated autoinflammatory diseases identified and characterized different disease phenotypes and their therapeutic approaches. This study is expected to contribute to increase the awareness of physicians for an early identification of these conditions, and to provide the best known therapeutic options.

A "SURFin' Leukemia": Acute Lymphoblastic Leukemia Masquerading as a Syndrome of Undifferentiated Recurrent Fever

Periodic fever is not uncommon in childhood and is often ascribed to autoinflammatory conditions; however, it may be present also in children with cancer. We here describe the case of a 3-year-old boy with acute lymphoblastic leukemia who initially presented with a 4-month history of recurrent, stereotyped episodes of fever and localized joint pain, separated by completely symptom-free intervals. These symptoms were initially interpreted as a possible syndrome of undifferentiated recurrent fever until more signs of leukemia became apparent. Our report confirms that acute lymphoblastic leukemia can rarely present with periodic fever, thus possibly leading to diagnostic errors unless a high index of suspicion is maintained.

Epidemiology and clinical features of PFAPA: a retrospective cohort study of 336 patients in western Sweden

BACKGROUND

Periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA) syndrome is generally regarded as the most common autoinflammatory disease, but the epidemiology of the disease is largely unknown. The objectives of this study were to estimate the annual incidence and describe the clinical features of PFAPA in a large cohort from western Sweden.

METHODS

The study retrospectively included children < 18 years of age diagnosed with PFAPA between 2006 and 2017 at three hospitals: NU Hospital Group, Skaraborg Hospital and Queen Silvia Children's Hospital. Patients were identified by searching for relevant diagnostic ICD-10 codes in the comprehensive electronic medical records and data were retrieved by reviewing case records. To estimate incidence, patients with symptom onset from January 1, 2006, to December 31, 2016, were included. Population data for the study area during this period were retrieved from Statistics Sweden.

RESULTS

In this study, 336 patients with PFAPA were identified. Of these, 156 (46%) were girls and 180 (54%) were boys. Almost 90% of the children with PFAPA (291 patients) experienced their first symptoms before the age of 5 years and fewer than 3% presented at ages above 10 years. Pharyngitis was the most common symptom during febrile episodes, followed by cervical adenitis and aphthous stomatitis. Fourteen percent of the patients displayed atypical features, of which skin rash was the most common. To calculate incidence, 251 patients with symptom onset during the study period were identified. The mean annual incidence was estimated at 0.86/10,000 for children < 18 years of age and 2.6/10,000 for children < 5 years of age.

CONCLUSIONS

This study adds to the understanding of the epidemiology of PFAPA syndrome by presenting incidence rates based on a large cohort and in different age groups in a population-based setting. It also shows the distribution of age of onset of PFAPA, with a peak in 1-year-olds and waning at older ages. Signs and symptoms of PFAPA syndrome were similar in children with symptom onset before vs. after 5 years of age.

Development and Implementation of the AIDA International Registry for Patients With Undifferentiated Systemic AutoInflammatory Diseases

Objective

This paper points out the design, development and deployment of the AutoInflammatory Disease Alliance (AIDA) International Registry dedicated to pediatric and adult patients affected by Undifferentiated Systemic AutoInflammatory Diseases (USAIDs).

Methods

This is an electronic registry employed for real-world data collection about demographics, clinical, laboratory, instrumental and socioeconomic data of USAIDs patients. Data recruitment, based on the Research Electronic Data Capture (REDCap) tool, is designed to obtain standardized information for real-life research. The instrument is endowed with flexibility, and it could change over time according to the scientific acquisitions and potentially communicate with other similar tools; this platform ensures security, data quality and data governance.

Results

The focus of the AIDA project is connecting physicians and researchers from all over the world to shed a new light on heterogeneous rare diseases. Since its birth, 110 centers from 23 countries and 4 continents have joined the AIDA project. Fifty-four centers have already obtained the approval from their local Ethics Committees. Currently, the platform counts 290 users (111 Principal Investigators, 179 Site Investigators, 2 Lead Investigators, and 2 data managers). The Registry is collecting baseline and follow-up data using 3,769 fields organized into 23 instruments, which include demographics, history, symptoms, trigger/risk factors, therapies, and healthcare information access for USAIDs patients.

Conclusions

The development of the AIDA International Registry for USAIDs patients will facilitate the online collection of real standardized data, connecting a worldwide group of researchers: the Registry constitutes an international multicentre observational groundwork aimed at increasing the patient cohort of USAIDs in order to improve our knowledge of this peculiar cluster of autoinflammatory diseases. NCT05200715 available at https://clinicaltrials.gov/.

Colchicine - an effective treatment for children with a clinical diagnosis of autoinflammatory diseases without pathogenic gene variants

BACKGROUND

Autoinflammatory diseases (AID) are rare chronic conditions with high disease burden, affecting children and adults. Clinically and genetically confirmed, AID can be effectively treated with targeted cytokine inhibition. In contrast, for patients with clinical AID symptoms without pathogenic gene variants, no treatment recommendations are available. Colchicine is approved and established as effective, safe and low-cost first-line therapy in Familial Mediterranean Fever. Up to now, efficacy data for colchicine in children with a clinical AID diagnosis without pathogenic gene variants are rare. This pilot study was performed to evaluate the effectiveness of colchicine in children with a clinical diagnosis of AID without pathogenic gene variants.

METHODS

A pilot cohort study of consecutive children with active clinical AID without pathogenic gene variants treated with colchicine monotherapy was performed between 01/2009 and 12/2018. Demographics, clinical and laboratory characteristics were determined serially. Colchicine dosing and safety were documented. Physician estimate of disease activity was captured on visual analogue scales (VAS).

PRIMARY OUTCOME

Complete response (PGA ≤2 plus CRP ≤0.5 mg/dL and/or SAA ≤10 mg/L) at last follow-up.

SECONDARY OUTCOMES

partial/no response, flare characteristics and requirement for rescue therapies.

ANALYSIS

Nonparametric comparison of disease activity measures.

RESULTS

A total of 33 children were included; 39% were female. Median age at colchicine start was 3.8 years, median follow-up was 14.1 months. Clinical AID diagnoses included CAPS (24%), FMF (27%), PFAPA (43%) and unclassified AID (6%). At baseline, overall disease activity was moderate (PGA 4), inflammatory markers were elevated (CRP 12.1 mg/dL; SAA 289.2 mg/L), and 97% reported febrile flares.

OUTCOME

55% achieved complete response, 35% showed partial response and 58% had no febrile flares at last follow-up. Inflammatory markers (SAA: p < 0.0001, CRP: p < 0.005) and disease activity (p < 0.0001) decreased significantly. Overall, 93% of children experienced improvement of flare characteristics.

CONCLUSION

Colchicine was found to be effective and safe in children with a clinical AID diagnosis in the absence of pathogenic gene variants. Colchicine is a low-cost treatment option for non-organ threatening AID.

Syndrome of Undifferentiated Recurrent Fever (SURF): An Emerging Group of Autoinflammatory Recurrent Fevers

Syndrome of undifferentiated recurrent fever (SURF) is a heterogeneous group of autoinflammatory diseases (AID) characterized by self-limiting episodes of systemic inflammation without a confirmed molecular diagnosis, not fulfilling the criteria for periodic fever, aphthous stomatitis, pharyngitis and adenopathy (PFAPA) syndrome. In this review, we focused on the studies enrolling patients suspected of AID and genotyped them with next generation sequencing technologies in order to describe the clinical manifestations and treatment response of published cohorts of patients with SURF. We also propose a preliminary set of indications for the clinical suspicion of SURF that could help in everyday clinical practice.

Generalized Cytokine Increase in the Setting of a Multisystem Clinical Disorder and Carcinoid Syndrome Associated with a Novel NLRP12 Variant

BACKGROUND

Nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs) are a group of cytoplasmic sensors that survey danger signals released by invading pathogens or damaged tissue. Mutations in the NLRP subfamily affect pro-inflammatory mediators and cause nonspecific systemic symptoms.

AIMS

We sought to identify a potential genetic etiology of an inflammatory syndrome in a patient that presented with an atypical multisystem illness with carcinoid syndrome as well as atopic and autoimmune features.

METHODS

Exome sequencing was performed using the Agilent SureSelect Clinical Research Exome XT kit on an Illumina HiSeq 2500. Longitudinal monitoring of pro-inflammatory cytokines was performed.

RESULTS

We identified a novel variant (heterozygous c.536C > T [p.Thr179Ile]) in the NLRP12 gene in a 63-year-old woman and her daughter, who presented with an unusual clinical syndrome that differs from autoinflammatory disorders previously reported in association with the NLRP subfamily gene mutations. This NLRP12 variant was predicted to be pathogenic by functional analysis through Hidden Markov Models (FATHMM). Both the mother and the daughter had episodes of abdominal pain, fever, diarrhea, skin rash, hypothyroidism, and elevated urine 5-hydroxyindoleacetic acid (5-HIAA) levels. The proband also had elevated serum levels of pro-inflammatory (IL-1β, IL-6, IL-12, and TNF-α), Th1 (IL-2, IFN-γ), and Th2 (IL-4, IL-5, IL-13) cytokines, but not of Th17 (IL-17) and IL-10.

CONCLUSION

This report adds to the expanding spectrum of clinical manifestations attributed to the NLRP subfamily gene variants and suggests a role of NLRP12 in the regulation of multiple cytokines.