Recurrent fever of unknown origin and unexplained bacteremia in a patient with a novel 4.5 Mb microdeletion in Xp11.23-p11.22.

Fever of unknown origin (FUO) remains a formidable diagnostic challenge in the field of medicine. Numerous studies suggest an association between FUO and genetic factors, including chromosomal abnormalities. Here, we report a female patient with a 4.5 Mb Xp microdeletion, who presented with recurrent FUO, bacteremia, colitis, and hematochezia. To elucidate the underlying pathogenic mechanism, we employed a comprehensive approach involving single cell RNA sequencing, T cell receptor sequencing, and flow cytometry to evaluate CD4 T cells. Analysis of peripheral blood mononuclear cells revealed augmented Th1, Th2, and Th17 cell populations, and elevated levels of proinflammatory cytokines in serum. Notably, the patient exhibited impaired Treg cell function, possibly related to deletion of genes encoding FOPX3 and WAS. Single cell analysis revealed specific expansion of cytotoxic CD4 T lymphocytes, characterized by upregulation of various signature genes associated with cytotoxicity. Moreover, interferon-stimulated genes were upregulated in the CD4 T effector memory cluster. Further genetic analysis confirmed maternal inheritance of the Xp microdeletion. The patient and her mother exhibited X chromosome-skewed inactivation, a potential protective mechanism against extensive X chromosome deletions; however, the mother exhibited complete skewing and the patient exhibited incomplete skewing (85:15), which may have contributed to emergence of immunological symptoms. In summary, this case report describes an exceptional instance of FUO stemming from an incompletely inactivated X chromosome microdeletion, thereby increasing our understanding of the genetics underpinning FUO.

[The most frequent febrile syndromes and autoinflammatory diseases in adulthood]. / Die häufigsten Fiebersyndrome und autoinflammatorischen Erkrankungen im Erwachsenenalter.

Autoinflammatory diseases are characterized by inflammatory manifestations in various organ systems, whereby recurrent febrile episodes, musculoskeletal complaints, gastrointestinal and cutaneous symptoms frequently occur accompanied by serological signs of inflammation. Autoinflammatory diseases include rare monogenic entities and multifactorial or polygenic diseases, which can manifest as a variety of symptoms in the course of time. Examples of monogenic autoinflammatory diseases are familial Mediterranean fever (FMF), cryopyrin-associated periodic syndrome (CAPS), tumor necrosis factor (TNF) receptor-associated periodic syndrome (TRAPS) and the recently described VEXAS (vacuoles, E1 enzyme, X­linked, autoinflammatory and somatic) syndrome. For non-monogenically determined autoinflammatory diseases, the most important representatives in adulthood are adult-onset Still's disease (AOSD) and the Schnitzler syndrome, in which a polygenic susceptibility and epigenetic factors are more likely to play a role.

Metagenomic next-generation sequencing for the diagnosis of fever of unknown origin in pediatric patients with hematological malignancy.

BACKGROUND AND AIMS: The aim of this study was to evaluate the performance of metagenomic next-generation sequencing (mNGS) in identifying microbiological etiologies in pediatric patients with hematological malignancies undergoing fever of unknown origin (FUO). METHODS: A total of 147 children with hematological malignancy suffering febrile diseases without definite microbiological etiologies under conventional tests were enrolled. The clinical record, serum inflammatory biomarkers and mNGS results were analyzed. RESULTS: At least one microorganism was identified by mNGS in 112 of 147 patients (76.2 %). Two or more types of organisms were detected simultaneously in 35.7 % (40/112) of samples. Of the 112 cases with positive mNGS results, the reported microorganisms were considered as etiologies of fever in 50 (44.6 %) cases. The initial antimicrobial regimens were adjusted according to the mNGS results in 48 cases, with 41 patients' febrile diseases resolved. Totally, 27.9 % (41/147) of patients benefit from mNGS. High IL-6 (>390 pg/mL) level was associated with bacterial infection and could help to interpret the results of mNGS. CONCLUSION: mNGS is a novel approach to determine the microbiological etiology of FUO in hematological malignancy patients, which benefits about a quarter of all patients tested. Integration of IL-6 can improve the diagnostic precision of bacterial infection.

Chromosomal abnormalities related to fever of unknown origin in a Chinese pediatric cohort and literature review.

BACKGROUND: Fever of unknown origin (FUO) has been difficult to diagnose in pediatric clinical practice. With the gradual change in the disease spectrum, genetic factors have received increasing attention. Limited studies have shown an association between FUO and chromosomal abnormalities. In this study, we investigated the clinical and genetic characteristics of patients with FUO presenting with chromosomal abnormalities in a Chinese pediatric cohort. RESULTS: Chromosomal abnormalities were detected in 5.5% (8/145) of the patients with FUO. Six patients with inflammatory fever presented with pharyngitis/amygdalitis (4/6), oral aphthous ulcer (2/6), digestive symptoms (3/6), developmental delay (4/6) and elevated C-reactive protein levels (6/6) during fever. These patients were often considered to have systemic inflammatory diseases, such as Behcet's disease or systemic juvenile idiopathic arthritis. Trisomy 8, 7q11.23 dup, 3p26.3-p26.1 del/17q12 dup, 22q11.21 del, and 6q23.3-q24.1 del were identified in patients with inflammatory fever. The TNFAIP3 gene was included in the 6q23.3-q24.1 deletion fragment. Two patients with central fever were characterized by facial anomalies, developmental delay, seizures and no response to antipyretic drugs and were identified as carrying the de novo 18q22.3-q23 del. By performing a literature review, an additional 19 patients who had FUO and chromosomal abnormalities were identified. Trisomy 8, 6q23.2-q24.3 del and 18q22.3-q23 del were reported to present as fever, similar to the findings of our study. CONCLUSIONS: We emphasized the important role of detecting chromosomal abnormalities in patients with FUO, especially in patients with systemic inflammatory manifestations or developmental delay. Identifying chromosomal abnormalities may change the diagnosis and management of patients with FUO.

The Application of Whole-Exome Sequencing in Patients With FUO.

BACKGROUND: Fever of unknown origin (FUO) is still a challenge for clinicians. Next-generation sequencing technologies, such as whole exome sequencing (WES), can be used to identify genetic defects in patients and assist in diagnosis. In this study, we investigated the application of WES in individuals with FUO. METHODS: We performed whole-exome sequencing on 15 FUO patients. Clinical information was extracted from the hospital information system. RESULTS: In 7/15 samples, we found positive results, including potentially causative mutations across eight different genes: CFTR, CD209, IRF2BP2, ADGRV 1, TYK2, MEFV, THBD and GATA2. CONCLUSIONS: Our results show that whole-exome sequencing can promote the genetic diagnosis and treatment of patients with FUO.

Clinical phenotypes and genetic analyses for diagnosis of systemic autoinflammatory diseases in adult patients with unexplained fever.

OBJECTIVE: To make an accurate diagnosis of systemic autoinflammatory diseases (SAIDs), clinical and genetic analyses were performed in patients with unexplained fever. METHODS: The clinical phenotype and genomic variants of 11 genes responsible for SAIDs were analyzed in 179 Japanese patients with unexplained fever. Genetic analysis was performed by next generation sequencing (NGS) on exons including exon-intron boundaries. RESULTS: Three cases met the diagnostic criteria for SAIDs other than familial Mediterranean fever (FMF). Considering 176 patients with unexplained fever, 43 cases (24.0%) were clinically diagnosed as FMF. Gene variants were found in 53 cases (30.1%) when searching for variants in the 10 disease genes other than the MEFV gene. Among them, the most frequently-identified genes were NLRP3, NOD2, NLRP12, NLRC4, and PLCG2, which accounted for 14, 7, 17, 7, and 6 cases, respectively. These variants were less than 1% of healthy individuals or novel variants, but not regarded as pathogenic since the patients did not meet the diagnostic criteria of SAIDs caused by their identified variants clinically. CONCLUSION: Twenty four percent of Japanese patients with unexplained fever were clinically diagnosed as FMF in this study. Low frequency but not pathogenic variants in genes other than MEFV were identified in 30.1% of the cases. It is not clear how much these gene variants contribute to the inflammatory phenotypes; therefore, further analysis would uncover their autoinflammatory phenotypes that cause fever.

Recurrent fever of unknown origin: An overlooked symptom of Fabry disease.

OBJECTIVE: Fabry disease (FD) is a rare X-linked lysosomal storage disorder due to the absent or deficient activity of lysosomal hydrolase a-galactosidase A (α-Gal A), which leads to the accumulation of its substrates in various organs and tissues. Classic clinical manifestations include angiokeratomas, proteinuria, renal failure, neuropathic pain, and left ventricular hypertrophy. Fever is one of the rare symptoms that may occur during FD. METHODS: Three Chinese Han patients with FD referred to Peking Union Medical College Hospital were reported. The complete medical records were established, and detailed data were collected. Whole-exome sequencing by next-generation sequencing and α-Gal A enzyme activity assay were performed to confirm the diagnosis. RESULTS: These three patients all presented with recurrent fever of unknown origin initially, accompanied with arthralgia/arthritis and other symptoms. We identified two known variants in the GLA gene, c.1176_1179delGAAG and c.782G>A (p.G261D), and a novel variant c.440G>A (p.G147E) which is likely pathogenic in our patient. CONCLUSIONS: FD should be considered as a rare cause of recurrent fever of unknown origin. The coexistence of gene variants related to systemic autoinflammatory diseases may make the clinical phenotypes of FD more complex and prone to recurrent fever.

Connecting the Dots From Fever of Unknown Origin to Myelodysplastic Syndrome: GATA2 Haploinsufficiency.

Leukemia-predisposing conditions, such as GATA2 haploinsufficiency, are known for their high penetrance and expressivity profiles. These disorders pose a difficult diagnostic challenge to even the most experienced clinician when they first present. We describe the case of a 17-year-old male presenting with features of nontuberculous mycobacterial infection, pulmonary fibrinoid granulomatous vasculitis, and myelodysplasia in the setting of a pathogenic GATA2 frameshift mutation confirmed by next-generation sequencing. The broad differential for GATA2 haploinsufficiency requires prompt recognition of key clinical features and laboratory abnormalities towards directing diagnosis and guiding appropriate and perhaps life-saving therapy.

Late Diagnosis of E148Q Mutation-Positive Familial Mediterranean Fever in a Kidney Transplant Patient With Fever of Unknown Origin: A Case Report.

Fever of unknown origin is a rare condition after solid organ transplant and is generally associated with atypical infections (eg, tuberculosis, fungal infections) and/or lymphoproliferative disorders. Here, we present a kidney transplant patient with a late diagnosis of E148Q mutation-positive familial Mediterranean fever as the cause of fever of unknown origin. A 22-year-old female patient with a previous history of 4 years of hemodialysis and unknown primary renal disease received a deceased-donor kidney transplant at our center 5 years previously. She had an uneventful course in the first 3 years following transplant. After this period, she was hospitalized 3 times during a 4-month period with fever, nausea, vomiting, and atypical abdominal pain. At that time, hemogram results were unremarkable, except for mild leukocytosis and slightly elevated acute-phase reactants; blood, urine, and throat cultures were negative, and there were no remarkable findings on imaging tests. Fever was controlled within 48 hours by administering empiric ampicillin-sulbactam therapy and discontinuing immunosuppressive treatment except steroids. Three successive hospital admissions owing to similar complaints suggested periodic fever syndrome, and therapy with 1 g/day colchicine led to an excellent clinical response with no recurrence of fever or other symptoms. An FMF gene mutation analysis revealed heterozygous E148Q mutation positivity. Continuing the current treatment regimen, the patient did well during at approximately 1.5 years of follow-up. In the Mediterranean region population, familial Mediterranean fever should be considered in the diagnosis of fever of unknown origin in patients who have undergone renal transplant. E148Q mutation-positive familial Mediterranean fever has a subclinical course and renal manifestations that differ from AA amyloidosis during childhood and may be responsible for de novo familial Mediterranean fever after renal transplantation.

[Recurrent fevers in childhood]. / Les fièvres récurrentes de l'enfant.

Recurrent fevers are defined as multiple stereotypical febrile episodes separated by spontaneous symptom-free intervals and occurring for months and years. Hereditary recurrent fevers are rare prototype Mendelian diseases due to inherited mutations in genes encoding partners of the innate immunity. Recurrent episodes of fever plus acute features of inflammation starting during childhood with family history are the main clues for suspecting HRF. Their common associated complication is AA amyloidosis. The diagnosis is made on clinical grounds but the genetic diagnosis may contribute in most cases of monogenic hereditary recurrent fevers. Recurrent fevers must be distinguished from intermittent fevers, mostly infectious, characterized by variation in associated symptoms from episode-to-episode and without periodicity.

Human herpes viruses are associated with classic fever of unknown origin (FUO) in Beijing patients.

BACKGROUND: Few reports have examined the viral aetiology of fever of unknown origin (FUO). OBJECTIVE: This study determined the prevalence of human herpes virus (HHV) DNA in blood of Chinese patients with classic FUO using the polymerase chain reaction (PCR) and explored the possible role of HHV. STUDY DESIGN: Blood samples were collected from 186 patients (151 children, 35 adults) with classic FUO and 143 normal individuals in Beijing during the years 2009-2012. The HHV DNA, including Herpes simplex virus (HSV)-1/2, Varicella zoster virus (VZV), Cytomegalovirus (CMV), Epstein-Barr virus (EBV), and Human herpes virus (HHV)-6 and -7, was detected by multiplex PCR. The epidemiological and clinical features were also analysed. RESULTS: HHV DNA was detected in 63 (33.9%) of the FUO patients, and the prevalence of EBV and HHV-6 was significantly higher than in the normal cohort. HHV co-infection was also frequent (10.2%) in the patients with FUO. The majority of patients with HHV infection present with a fever only. Our data also revealed that EBV infection was associated with hepatitis and abnormal blood indices, HHV-6 was associated with a cough, and HHV-7 was associated with hepatitis. CONCLUSIONS: HHVs are associated with Chinese patients (especially for children) with classic FUO. Our study adds perspective to the aetiological and clinical characteristics of classic FUO in beijing patients.

Clinically symptomatic heterozygous carnitine palmitoyltransferase II (CPT II) deficiency.

Two symptomatic patients with heterozygous carnitine palmitoyltransferase II (CPT II) deficiency are reported. Patient 1, a 21-year-old female professional tennis player, suffered from exercise-induced attacks of muscle pain, burning sensations and proximal weakness. Patient 2, a 30-year-old male amateur marathon runner developed muscle cramps and rhabdomyolysis upon extensive exercise and insolation-induced fever. In both patients, the common p.S113L mutation was found in heterozygote state. No second mutation could be found upon sequencing of all the exons of CPT2 gene including exon-intron boundaries. Biochemically, residual CPT activity in muscle homogenate upon inhibition by malonyl-CoA and Triton-X-100 was intermediate between controls and patients with mutations on both alleles. Although CPT II deficiency is an autosomal recessive disorder, the reported patients indicate that heterozygotes might also have typical attacks of myalgia, pareses or rhabdomyolysis.

Clinical, genetic, and therapeutic diversity in 2 patients with severe mevalonate kinase deficiency.

Mevalonic aciduria (MA) represents the severest form of mevalonate kinase deficiency due to recessively inherited, loss-of-function MVK mutations. MA is an early-onset disorder characterized by a marked failure to thrive, diverse neurologic symptoms, dysmorphic features, and recurrent febrile episodes. However, significant clinical differences have been reported in the few cases published to date. Here we describe 2 unrelated Spanish patients with MA, emphasizing the clinical heterogeneity observed. One patient presented with the severe classic MA phenotype due to the homozygous p.Ile-268-Thr MVK genotype, with a poor response to conventional treatments. However, the anti-interleukin 1 agent anakinra in this patient resulted in improvement in many clinical and laboratory parameters. The second patient presented with an atypical milder phenotype because of an older age at disease onset, mild neurologic symptoms, absence of febrile episodes and dysmorphic features, and moderate-to-good response to conventional treatments. The novel p.Arg-241-Cys MVK mutation, associated with the already known p.Ser-135-Leu mutation, detected in this patient expands the genetic diversity of mevalonate kinase deficiency. This atypical presentation of MA suggests that it should be included in the differential diagnosis of unclassified patients with psychomotor retardation, failure to thrive or ataxia, even in the absence of febrile episodes.

Differentiating PFAPA syndrome from monogenic periodic fevers.

OBJECTIVES: To analyze whether there were clinical differences between genetically positive and negative patients fulfilling periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome criteria and to test the accuracy of the Gaslini diagnostic score for identifying patients with PFAPA syndrome with higher probabilities of carrying relevant mutations in genes associated with periodic fevers. METHODS: Complete clinical and genetic information was available for 393 children with periodic fever; 82 had positive genetic test results, 75 had incomplete genetic test results, and 236 had negative results for MVK, TNFRSF1A, and MEFV mutations. Current diagnostic criteria for PFAPA syndrome were applied. RESULTS: Of 393 children, 210 satisfied PFAPA syndrome criteria; 43 carried diagnostic mutations (mevalonate kinase deficiency: n = 33; tumor necrosis factor receptor-associated periodic syndrome: n = 3; familial Mediterranean fever: n = 7), 37 displayed low-penetrance mutations or incomplete genotypes, and 130 demonstrated negative genetic testing results. Genetically positive patients had higher frequencies of abdominal pain and diarrhea (P < .001), vomiting (P = .006), and cutaneous rash and arthralgia (P = .01). Genetically negative patients had a higher frequency of exudative pharyngitis (P = .010). Genetically undetermined patients showed the same pattern of symptom frequency as genetically negative patients. The Gaslini diagnostic score was able to identify 91% of genetically positive patients correctly, with a global accuracy of 66%. CONCLUSION: The Gaslini diagnostic score represents a useful tool to identify patients meeting PFAPA syndrome criteria and at low risk of carrying relevant mutations in genes associated with periodic fevers.

A clinical criterion to exclude the hyperimmunoglobulin D syndrome (mild mevalonate kinase deficiency) in patients with recurrent fever.

OBJECTIVE: The hyperimmunoglobulin D syndrome (HIDS) is an autosomal recessive autoinflammatory disease caused by mutations in the mevalonate kinase gene. Our objective was to define a clinical criterion able to exclude HIDS without the need of genetic testing. METHODS: A recursive partitioning algorithm was applied to derive the clinical criterion in 149 patients with genetic testing in a French laboratory, among whom 35 had HIDS. The criterion was validated in 93 patients with genetic testing in a Dutch laboratory, among whom 28 had HIDS. RESULTS: The most discriminatory composite clinical criterion satisfied by all patients with HIDS in the derivation group was [onset age < 5 years old OR (joint pain during attacks AND length of attacks < 14 days)]. It had a sensitivity of 100% (95% confidence interval 88% to 100%) and a specificity of 28% (95% CI 17% to 40%) in the validation group. If genetic testing had been limited to patients fulfilling this criterion, 18 tests (19%) would have been avoided in this highly selected validation sample, without missing a single patient with HIDS. CONCLUSION: Even among patients already selected by expert physicians, this criterion could help prevent unnecessary genetic testing, which is resource- and time-consuming.