Kingella endocarditis and meningitis in a patient with SLE and associated antiphospholipid syndrome

Kingella kingae Intrauterine Infection: An Unusual Cause of Chorioamnionitis and Miscarriage in a Patient with Undifferentiated Connective Tissue Disease

Kingella kingae is a Gram-negative coccobacillus belonging to the Neisseriaceae family. In children less than 4 years old, K. kingae invasive infection can induce septic arthritis and osteomyelitis, and more rarely endocarditis, meningitis, ocular infections, and pneumonia. In adults, it may be a cause of endocarditis. To date, K. kingae acute chorioamnionitis (AC) leading to preterm rupture of membranes (PPROM) and miscarriage has never been reported. Herein, we describe a case of intrauterine fetal death (IUFD) at 22 weeks’ gestation due to K. kingae infection occurred in a patient affected by undifferentiated connective tissue disease (UCTD) in lupus erythematosus systemic (LES) evolution with severe neutropenia. K. kingae was isolated in placental subamnionic swab and tissue cultures as well as fetal ear, nose, and pharyngeal swabs. Placental histological examination showed necrotizing AC and funisitis. In the fetus, neutrophils were observed within the alveoli and in the gastrointestinal lumen. Maternal medical treatment for UCTD was modified according to the K. kingae invasive infection. In the event of IUFD due to AC, microbiological cultures on placenta and fetal tissues should always be carried out in order to isolate the etiologic agent and target the correct medical treatment.

Coexistence of antiphospholipid antibodies and cephalalgia

Background

The occurrence of antiphospholipid antibodies (aPLs) and headache comorbidity in the presence or absence of underlying autoimmune diseases remains unclear.

Aim

The aim of this review was to summarize the relationship between headache and aPLs based on evidences from cohort studies and case reports, in addition to examining the treatment strategies that resolved headache in aPLs-positive individuals.

Methods

A comprehensive literature search was conducted through PubMed, ISI Web of Science and Google Scholar. A total of 559 articles were screened and the appropriate articles were selected based on quality and level of evidence.

Results

Cohort studies (n = 27) from Europe, North America and Asia demonstrated comorbidity of aPLs and headache in antiphospholipid syndrome, systemic lupus erythematosus (SLE) and neuropsychiatric SLE patients. Significantly higher association between migraine and aPLs was observed (n = 170/779; p < 0.0001) in individuals without any underlying diseases. Our analysis of shortlisted case reports (n = 17) showed that a higher frequency of anticardiolipin antibodies were present in subjects with different autoimmune disorders (70.6%). Corticosteroids were highly effective in resolving headache in aPLs-positive individuals.

Conclusion

Higher frequency of comorbidity between aPLs and headache was observed in healthy individuals and patient cases. Therefore, experimental studies are warranted to evaluate the aPLs-induced pathogenic mechanism of headache.

Kingella kingae infections in children

BACKGROUND

Improvements in culture techniques and molecular detection methods have led to findings indicating that, particularly in infants and young children, Kingella kingae is a significantly more important pathogen than previously thought. However, despite this, the pediatric community is still largely unaware of the existence of this organism. The aim of this review is therefore to summarise current knowledge of the epidemiology, transmission, clinical presentation, diagnosis and treatment of K. kingae infections in children.

DISCUSSION

K. kingae is a common coloniser of the oropharynx, can be transmitted from child to child, and can cause outbreaks of infection. Invasive infections almost exclusively occur in children aged between six months and four years of age, and involve mainly joints and bone, less frequently the endocardium, and very rarely other localisations. With the exception of bacteremia and endocarditis, which can be followed by severe complications, the diseases due to K. kingae are usually accompanied by mild to moderate clinical signs and symptoms, and only slightly altered laboratory data. Moreover, they generally respond to widely used antibiotics, although resistant strains are reported. However, the mild symptoms and limited increase in the levels of acute phase reactants create problems because K. kingae disease may be confused with other clinical conditions that have a similar clinical picture.

CONCLUSIONS

Although K. kingae was identified more than 50 years ago, it is poorly known by pediatricians and is not systematically sought in laboratories. Education is therefore necessary in order to reduce the risk of outbreaks, permit the early identification of K. kingae infections, and allow the prompt prescription of adequate therapeutic regimens capable of avoiding the risk of a negative evolution in those cases in which this elusive pathogen can cause significant clinical problems.

Kingella kingae: carriage, transmission, and disease

Kingella kingae is a common etiology of pediatric bacteremia and the leading agent of osteomyelitis and septic arthritis in children aged 6 to 36 months. This Gram-negative bacterium is carried asymptomatically in the oropharynx and disseminates by close interpersonal contact. The colonized epithelium is the source of bloodstream invasion and dissemination to distant sites, and certain clones show significant association with bacteremia, osteoarthritis, or endocarditis. Kingella kingae produces an RTX (repeat-in-toxin) toxin with broad-spectrum cytotoxicity that probably facilitates mucosal colonization and persistence of the organism in the bloodstream and deep body tissues. With the exception of patients with endocardial involvement, children with K. kingae diseases often show only mild symptoms and signs, necessitating clinical acumen. The isolation of K. kingae on routine solid media is suboptimal, and detection of the bacterium is significantly improved by inoculating exudates into blood culture bottles and the use of PCR-based assays. The organism is generally susceptible to antibiotics that are administered to young patients with joint and bone infections. β-Lactamase production is clonal, and the local prevalence of β-lactamase-producing strains is variable. If adequately and promptly treated, invasive K. kingae infections with no endocardial involvement usually run a benign clinical course.

Molecular diagnosis of Kingella kingae pericarditis by amplification and sequencing of the 16S rRNA gene

Kingella kingae is a fastidious gram-negative bacillus that is considered an emerging pathogen in pediatric settings but remains less common in adults. Here we describe a case of pericarditis in an immunocompetent adult host. The microorganism was identified directly from the clinical sample by molecular techniques, i.e., 16S rRNA gene amplification and sequencing.

Kingella kingae: from medical rarity to an emerging paediatric pathogen

In recent years, Kingella kingae has emerged as an important cause of invasive infections in young children, especially septic arthritis, osteomyelitis, spondylodiscitis, bacteraemia, and endocarditis, and less frequently lower respiratory tract infections and meningitis. The organism is part of the pharyngeal flora of young children and is transmitted from child-to-child. The clinical presentation of invasive K kingae disease is often subtle and laboratory tests are frequently normal. A substantial fraction of children with invasive K kingae infections have a recent history of stomatitis or symptoms of upper-respiratory-tract infection. The organism is susceptible to a wide array of antibiotics that are usually given empirically to young children including beta lactams, and with the exception of cases of endocarditis, the disease runs a benign clinical course. Although isolation and recognition of the organism is not difficult, clinicians and microbiologists should be aware of its fastidious nature. To optimise the recovery of K kingae, inoculation of synovial fluid specimens into blood culture vials is strongly recommended.