Ventriculitis and hydrocephalus caused by Candida albicans successfully treated by antimycotic therapy and cerebrospinal fluid shunting

From Mendel to mycoses: Immuno-genomic warfare at the human-fungus interface

Fungi are opportunists: They particularly require a defect of immunity to cause severe or disseminated disease. While often secondary to an apparent iatrogenic cause, fungal diseases do occur in the absence of one, albeit infrequently. These rare cases may be due to an underlying genetic immunodeficiency that can present variably in age of onset, severity, or other infections, and in the absence of a family history of disease. They may also be due to anti-cytokine autoantibodies. This review provides a background on how human genetics or autoantibodies underlie cases of susceptibility to severe or disseminated fungal disease. Subsequently, the lessons learned from these inborn errors of immunity marked by fungal disease (IEI-FD) provide a framework to begin to mechanistically decipher fungal syndromes, potentially paving the way for precision therapy of the mycoses.

The molecular immunology of human susceptibility to fungal diseases: lessons from single gene defects of immunity

INTRODUCTION

Fungal diseases are a threat to human health. Therapies targeting the fungus continue to lead to disappointing results. Strategies targeting the host response represent unexplored opportunities for innovative treatments. To do so rationally requires the identification and neat delineation of critical mechanistic pathways that underpin human antifungal immunity. The study of humans with single-gene defects of the immune system, i.e. inborn errors of immunity (IEIs), provides a foundation for these paradigms. Areas covered: A systematic literature search in PubMed, Scopus, and abstracts of international congresses was performed to review the history of genetic resistance/susceptibility to fungi and identify IEIs associated with fungal diseases. Immunologic mechanisms from relevant IEIs were integrated with current definitions and understandings of mycoses to establish a framework to map out critical immunobiological pathways of human antifungal immunity. Expert opinion: Specific immune responses non-redundantly govern susceptibility to their corresponding mycoses. Defining these molecular pathways will guide the development of host-directed immunotherapies that precisely target distinct fungal diseases. These findings will pave the way for novel strategies in the treatment of these devastating infections.

Inherited CARD9 deficiency in otherwise healthy children and adults with Candida species-induced meningoencephalitis, colitis, or both

BACKGROUND

Invasive infections of the central nervous system (CNS) or digestive tract caused by commensal fungi of the genus Candida are rare and life-threatening. The known risk factors include acquired and inherited immunodeficiencies, with patients often displaying a history of multiple infections. Cases of meningoencephalitis, colitis, or both caused by Candida species remain unexplained.

OBJECTIVE

We studied 5 previously healthy children and adults with unexplained invasive disease of the CNS, digestive tract, or both caused by Candida species. The patients were aged 39, 7, 17, 37, and 26 years at the time of infection and were unrelated, but each was born to consanguineous parents of Turkish (2 patients), Iranian, Moroccan, or Pakistani origin. Meningoencephalitis was reported in 3 patients, meningoencephalitis associated with colitis was reported in a fourth patient, and the fifth patient had colitis only.

METHODS

Inherited caspase recruitment domain family, member 9 (CARD9) deficiency was recently reported in otherwise healthy patients with other forms of severe disease caused by Candida, Trichophyton, Phialophora, and Exophiala species, including meningoencephalitis but not colitis caused by Candida and Exophiala species. Therefore we sequenced CARD9 in the 5 patients.

RESULTS

All patients were found to be homozygous for rare and deleterious mutant CARD9 alleles: R70W and Q289* for the 3 patients with Candida albicans-induced meningoencephalitis, R35Q for the patient with meningoencephalitis and colitis caused by Candida glabrata, and Q295* for the patient with Candida albicans-induced colitis. Regardless of their levels of mutant CARD9 protein, the patients' monocyte-derived dendritic cells responded poorly to CARD9-dependent fungal agonists (curdlan, heat-killed C albicans, Saccharomyces cerevisiae, and Exophiala dermatitidis).

CONCLUSION

Invasive infections of the CNS or digestive tract caused by Candida species in previously healthy children and even adults might be caused by inherited CARD9 deficiency.

Reinfection following initial cerebrospinal fluid shunt infection

OBJECT

Significant variation exists in the surgical and medical management of CSF shunt infection. The objectives of this study were to determine CSF shunt reinfection rates following initial CSF shunt infection in a large patient cohort and to determine management, patient, hospital, and surgeon factors associated with CSF shunt reinfection.

METHODS

This retrospective cohort study included children who were in the Pediatric Health Information System (PHIS) database, who ranged in age from 0 to 18 years, and who underwent uncomplicated initial CSF shunt placement in addition to treatment for initial CSF shunt infection between January 1, 2001, and December 31, 2008. The outcome was CSF shunt reinfection within 6 months. The main predictor variable of interest was surgical approach to treatment of first infection, which was determined for 483 patients. Covariates included patient, hospital, surgeon, and other management factors.

RESULTS

The PHIS database includes 675 children with initial CSF shunt infection. Surgical approach to treatment of the initial CSF shunt infection was determined for 483 children (71.6%). The surgical approach was primarily shunt removal/new shunt placement (in 286 children [59.2%]), but a substantial number underwent externalization (59 children [12.2%]), of whom a subset went on to have the externalized shunt removed and a new shunt placed (17 children [3.5% overall]). Other approaches included nonsurgical management (64 children [13.3%]) and complete shunt removal without shunt replacement (74 children [15.3%]). The 6-month reinfection rate was 14.8% (100 of 675 patients). The median time from infection to reinfection was 21 days (interquartile range [IQR] 5-58 days). Children with reinfection had less time between shunt placement and initial infection (median 50 vs 79 days, p = 0.06). No differences between those with and without reinfection were seen in patient factors (patient age at either shunt placement or initial infection, sex, race/ethnicity, payer, indication for shunt, number of comorbidities, distal shunt location, and number of shunt revisions at first infection); hospital volume; surgeon volume; or other management factors (for example, duration of intravenous antibiotic use). Nonsurgical management was associated with reinfection, and complete shunt removal was negatively associated with reinfection. However, reinfection rates did not differ between the 2 most common surgical approaches: shunt removal/new shunt placement (44 [15.4%] of 286; 95% CI 11.4%-20.1%) and externalization (total 12 [20.3%] of 59; 95% CI 11.0%-32.8%). Externalization followed by shunt removal/new shunt placement (5 [29.4%] of 17; 95% CI 10.3%-56.0%) and nonsurgical management (15 [23.4%] of 64; 95% CI 13.8%-35.7%) had higher, but nonstatistically significant, reinfection rates. The length of stay was shorter for nonsurgical management.

CONCLUSIONS

Surgical approach to treatment of initial CSF shunt infection was not associated with reinfection in this large cohort of patients.

Brain abscess formation as a CSF shunt complication: a case report

The formation of a brain abscess as a result of a cerebrospinal fluid shunt complication is extremely rare in the literature with only 7 cases reported in the last 20 years. We report a patient that developed a brain abscess adjacent to a functioning ventricular catheter in the presence of shunt infection by another pathogen. Clinicians should consider this complication in any shunted patient with clinical features of infection and suggestive changes on imaging however subtle. Expedited standard management for the abscess and the CSF shunt infection, if present, should be employed. Removal of all non-functioning catheters should be encouraged.

[Candida albicans cerebral granuloma in an immunocompetent patient. A case report]

We report a case of temporal lobe granuloma caused by Candida albicans in an immunocompetent patient. This 54-year-old patient had experienced headaches and some memory disorders for two to three months before his admission to the neurosurgical department. Cerebral-computer tomography and magnetic resonance imaging showed a single right-temporal lesion with a large peritumoral edema. We operated on the patient via a temporal approach using neuronavigation and resected the lesion. The anatomopathological result and the cultures of the granuloma showed C. albicans species. The patient received antifungal therapy for three months. No predisposing factors or immunosuppression was found. After seven months, he presented an ischemic cerebrovascular accident of the brain stem and then chronic meningitis complicated by hydrocephalus. The patient's condition progressively deteriorated and he died 18 months later in an other department. C. albicans can be found even in the immunocompetent patient, but is seldom observed. Surgery can provide an accurate diagnosis and therapeutic management in the initial phase, completed by antifungal therapy.

Polysaccharide mannan components of Candida albicans and Saccharomyces cerevisiae cell wall produce fever by intracerebroventricular injection in rats

The cell wall mannan components of Candida albicans and Saccharomyces cerevisiae produced hyperthermic responses when injected intracerebroventricularly at doses of 10 microg in rats. Indomethacin treatment (5 mg/kg subcutaneously) completely abolished these responses. Serum interferon-gamma, tumor necrosis factor-alpha and interleukin-1beta levels showed an upward trend during the initial phase of the hyperthermic response induced by S. cerevisiae mannan. Meanwhile, serum levels of these proinflammatory cytokines did not increase at all at the initial phase of C. albicans mannan-induced hyperthermia. Histopathological examination of the brain tissue samples revealed no specific change throughout the parenchyma of rats given either mannan. These results indicate that the polysaccharide mannan components of yeasts, regardless of the pathogenicity, produce a pyrogenic response by a direct injection into the brain in rats. This response is not accompanied by proinflammatory cytokine induction in the periphery.

Postinflammatory hydrocephalus and intracranial mass lesion from Candida in an immunocompetent child

Central nervous system Candida infection may occur in systemic Candida infection when host defenses are impaired. We report here a 20-month-old boy with normal immune status and no history of immunosuppressive therapy who developed left facial weakness, decreased left hand strength and coordination, and worsening gait. This paper describes the diagnostic procedures and management strategies employed in this unique case.

Fever of unknown origin: due to C. albicans or other fungi acting on the hypothalamus?

Recently, it was shown that cerebrospinal fluid (CSF) contaminated with the fungus Trichosporon beigelii produces an intense fever when the organism is microinjected directly into the thermosensitive region of the anterior hypothalamic preoptic area (AH/POA). The purpose of this study was to determine if the AH/POA possesses a corresponding sensitivity to another fungal organism, Candida albicans. In adult male Sprague-Dawley rats, an intracerebral cannula was implanted stereotaxically above the AH/POA and a radio transmitter for the continuous recording of body temperature (Tb) was placed in the peritoneal cavity. After recovery, one of two solutions was microinjected in the AH/POA: a pyrogen-free, filtered artificial CSF and a second cultured with C. albicans in a concentration of approximately 12 x 10(8) organisms/ml. Whereas the filtered CSF failed to evoke a significant rise in Tb, C. albicans produced a febrile response of 0.8-1.5 degrees C in the rats within 1 h after its microinjection into the AH/POA. This fever persisted typically for > or = 12 h but after 24 h Tb returned to the baseline. Histological examination of the cerebral tissue postmortem revealed focally extensive granulomatous encephalitis with disseminated inflammation throughout the parenchyma of rats given repeated microinjections of C. albicans. Since C. albicans is a highly potent pyrogen acting directly on thermosensitive neurons, it is envisaged that a massive accumulation of the organism within the brain could be responsible pathologically for the protracted fever "of unknown origin" which gives rise to clinical morbidity.