[Brain abscesses caused by Nocardia farcinica in a kidney transplanted man]

Nocardiosis is primarily an opportunistic infection caused by aerobic Gram-positive bacteria of the genus Nocardia. In this case report we describe a male patient who previously received a kidney transplant and was admitted to hospital with chills, headache and pain in the neck and left eye, tremor and coordination problems. A magnetic resonance scan of the brain showed multiple abscesses, and blood culture was positive for Nocardia farcinica. Nocardiosis of the central nervous system is a rare, but serious differential diagnosis in immunosuppressed patients with signs of high intracranial pressure.

Cytokines and chemokines at the crossroads of neuroinflammation, neurodegeneration, and neuropathic pain

Cytokines and chemokines are proteins that coordinate the immune response throughout the body. The dysregulation of cytokines and chemokines is a central feature in the development of neuroinflammation, neurodegeneration, and demyelination both in the central and peripheral nervous systems and in conditions of neuropathic pain. Pathological states within the nervous system can lead to activation of microglia. The latter may mediate neuronal and glial cell injury and death through production of proinflammatory factors such as cytokines and chemokines. These then help to mobilize the adaptive immune response. Although inflammation may induce beneficial effects such as pathogen clearance and phagocytosis of apoptotic cells, uncontrolled inflammation can result in detrimental outcomes via the production of neurotoxic factors that exacerbate neurodegenerative pathology. In states of prolonged inflammation, continual activation and recruitment of effector cells can establish a feedback loop that perpetuates inflammation and ultimately results in neuronal injury. A critical balance between repair and proinflammatory factors determines the outcome of a neurodegenerative process. This review will focus on how cytokines and chemokines affect neuroinflammation and disease pathogenesis in bacterial meningitis and brain abscesses, Lyme neuroborreliosis, human immunodeficiency virus encephalitis, and neuropathic pain.

Minocycline modulates neuroinflammation independently of its antimicrobial activity in staphylococcus aureus-induced brain abscess

Minocycline exerts beneficial immune modulatory effects in several noninfectious neurodegenerative disease models; however, its potential to influence the host immune response during central nervous system bacterial infections, such as brain abscess, has not yet been investigated. Using a minocycline-resistant strain of Staphylococcus aureus to dissect the antibiotic's bacteriostatic versus immune modulatory effects in a mouse experimental brain abscess model, we found that minocycline significantly reduced mortality rates within the first 24 hours following bacterial exposure. This protection was associated with a transient decrease in the expression of several proinflammatory mediators, including interleukin-1beta and CCL2 (MCP-1). Minocycline was also capable of protecting the brain parenchyma from necrotic damage as evident by significantly smaller abscesses in minocycline-treated mice. In addition, minocycline exerted anti-inflammatory effects when administered as late as 3 days following S. aureus infection, which correlated with a significant decrease in brain abscess size. Finally, minocycline was capable of partially attenuating S. aureus-dependent microglial and astrocyte activation. Therefore, minocycline may afford additional therapeutic benefits extending beyond its antimicrobial activity for the treatment of central nervous system infectious diseases typified by a pathogenic inflammatory component through its ability to balance beneficial versus detrimental inflammation.

MyD88-dependent signals are essential for the host immune response in experimental brain abscess

Brain abscesses form in response to a parenchymal infection by pyogenic bacteria, with Staphylococcus aureus representing a common etiologic agent of human disease. Numerous receptors that participate in immune responses to bacteria, including the majority of TLRs, the IL-1R, and the IL-18R, use a common adaptor molecule, MyD88, for transducing activation signals leading to proinflammatory mediator expression and immune effector functions. To delineate the importance of MyD88-dependent signals in brain abscesses, we compared disease pathogenesis using MyD88 knockout (KO) and wild-type (WT) mice. Mortality rates were significantly higher in MyD88 KO mice, which correlated with a significant reduction in the expression of several proinflammatory mediators, including but not limited to IL-1beta, TNF-alpha, and MIP-2/CXCL2. These changes were associated with a significant reduction in neutrophil and macrophage recruitment into brain abscesses of MyD88 KO animals. In addition, microglia, macrophages, and neutrophils isolated from the brain abscesses of MyD88 KO mice produced significantly less TNF-alpha, IL-6, MIP-1alpha/CCL3, and IFN-gamma-induced protein 10/CXCL10 compared with WT cells. The lack of MyD88-dependent signals had a dramatic effect on the extent of tissue injury, with significantly larger brain abscesses typified by exaggerated edema and necrosis in MyD88 KO animals. Interestingly, despite these striking changes in MyD88 KO mice, bacterial burdens did not significantly differ between the two strains at the early time points examined. Collectively, these findings indicate that MyD88 plays an essential role in establishing a protective CNS host response during the early stages of brain abscess development, whereas MyD88-independent pathway(s) are responsible for pathogen containment.

Multiple Aspergillus brain abscesses in immuno-competent patient with severe cranio-facial trauma

Aspergillosis of the central nervous system (CNS) is a rare, but well described disease in immuno-competent patients. We present a 65-year-old patient who developed neuro-aspergillosis 10 months after severe cranio-facial trauma (Le Fort III). He was treated successfully with surgery including stereotactic drainage and, with Amphotericin B, Liposomal Amphotericin B, and Itraconazol.

Nestin expression in reactive astrocytes of human pathology

There is a general agreement on the Nestin re-expression in reactive astrocytes, but its modalities differ among experimental animal species and between the latter and human material. In a series of 40 surgical specimens, including gliomas, vascular malformations, abscesses and angiomas, the glial reaction has been studied by immunohistochemistry and immunofluorescence of Nestin, GFAP and Vimentin. The observations made by immunohistochemistry were comparable with those by immunofluorescence. In some lesions, glial reaction was long-lasting and astrocytes were in the same late maturation stage. In other lesions, such as invading malignant gliomas, astrocytes occurred in different maturation stages. In comparison with GFAP, Nestin was poorly expressed in mature astrocytes and more expressed in developing reactive astrocytes, mainly in the cytoplasms, with a great variability, and much less in the processes. In the invading tumor, developing positive astrocytes were hardly distinguishable from tumor invading astrocytes that, interestingly, were much more Nestin- than GFAP-positive. In the deep tumor reactive astrocytes were no more visible. The interpretation of the findings was based on what is known on the reciprocal behavior of the three antigens in maturing astrocytes during embryogenesis and on the hypothesis of an embryonic regression of reactive astrocytes. The impossibility to distinguish them from tumor cells in the deep tumor legitimates the suspicion of their recruitment among tumor cells.

Toll-like receptor 2 modulates the proinflammatory milieu in Staphylococcus aureus-induced brain abscess

Toll-like receptor 2 (TLR2) is a pattern recognition receptor (PRR) that plays an important role in innate immune recognition of conserved structural motifs on a wide array of pathogens, including Staphylococcus aureus. To ascertain the functional significance of TLR2 in the context of central nervous system (CNS) parenchymal infection, we evaluated the pathogenesis of S. aureus-induced experimental brain abscess in TLR2 knockout (KO) and wild-type (WT) mice. The expression of several proinflammatory mediators, including inducible nitric oxide synthase, tumor necrosis factor alpha, and macrophage inflammatory protein-2, was significantly attenuated in brain abscesses of TLR2 KO mice compared to WT mice during the acute phase of infection. Conversely, interleukin-17 (IL-17), a cytokine produced by activated and memory T cells, was significantly elevated in lesions of TLR2 KO mice, suggesting an association between innate and adaptive immunity in brain abscess. Despite these differences, brain abscess severity in TLR2 KO and WT animals was similar, with comparable mortality rates, bacterial titers, and blood-brain barrier permeability, implying a role for alternative PRRs. Expression of the phagocytic PRRs macrophage scavenger receptor type AI/AII and lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) was increased in brain abscesses of both TLR2 KO and WT mice compared to uninfected animals. However, LOX-1 induction in brain abscesses of TLR2 KO mice was significantly attenuated compared to WT animals, revealing that the TLR2-dependent signal(s) influence LOX-1 expression. Collectively, these findings reveal the complex nature of gram-positive bacterial recognition in the CNS which occurs, in part, through engagement of TLR2 and highlight the importance of receptor redundancy for S. aureus detection in the CNS.

Toll-like receptor 2 (TLR2) is pivotal for recognition of S. aureus peptidoglycan but not intact bacteria by microglia

Toll-like receptor 2 (TLR2) is a pattern recognition receptor that plays an important role in enabling cells of the innate immune system to recognize conserved structural motifs on a wide array of pathogens including gram-positive bacteria. Although microglia have recently been shown to express TLR2, the functional significance of this receptor in mediating microglial activation remains unknown. To ascertain the importance of TLR2 in microglial responses to S. aureus and its cell wall product peptidoglycan (PGN), we evaluated primary microglia from TLR2 knockout (KO) and wild-type (WT) mice. TLR2 was found to play a pivotal role in PGN recognition and subsequent activation in primary microglia, as demonstrated by the attenuated expression of TNF-alpha, IL-12 p40, MIP-2, and MCP-1 in PGN-treated TLR2 KO microglia compared with WT cells. In contrast, the responses of TLR2 KO and WT microglia to S. aureus were qualitatively similar, indicating that alternative receptors are responsible for recognizing intact bacteria. Microarray analysis confirmed that TLR2 plays a central role in PGN recognition by primary microglia. The expression of MyD88, a central adapter molecule in TLR-dependent signaling, was similar in both TLR2 KO and WT microglia, suggesting that the defect in PGN recognition by the former is not due to alterations in this key signaling intermediate. These findings reveal the complex nature of gram-positive bacterial recognition by microglia, which occurs, in part, through engagement of TLR2.

Rhodococcus equi brain abscess in a patient without HIV

Rhodococcus equi, a Gram positive organism, is a cause of infections in immunocompromised individuals. In humans, it mainly causes disease in those infected with human immunodeficiency virus (HIV), and generally presents as chronic pulmonary infection. It may also cause intracranial infections, which manifest as brain abscesses. This report describes a case of rhodococcus brain and pulmonary infection in a patient who did not have HIV or another disorder of cell mediated immunity. He was treated with intravenous imipenem, vancomycin, and rifampin for eight weeks and recovered from the infection.

An essential role for tumor necrosis factor in the formation of experimental murine Staphylococcus aureus-induced brain abscess and clearance

Tumor necrosis factor-alpha (TNF-alpha) is a central mediator of the immune response to pathogens, but may also exert neurotoxic effects, thereby contributing to immunopathology. To define the role of TNF during the course of brain abscess, TNF-deficient (TNF(0/0) mice were stereotaxically infected with Staphylococcus (S.) aureus-laden agarose beads. In comparison to 100% survival of wild type (WT) mice, TNF(0/0) mice displayed high mortality rates (54%) in the initial phase of abscess development as well as significantly increased morbidity in the course of the disease. The worse clinical outcome was due to an increased intracerebral (i.c.) bacterial load in TNF(0/0) mice as compared to WT mice. The impaired control of S. aureus was associated with reduced inductible nitric oxide synthase (iNOS) mRNA and protein expression in TNF(0/0)mice. Similarly, numbers of inflammatory leukocytes, cytokine expression of IL-6, IL-12p40, IFNgamma IL-beta mRNA, and brain edema were significantly increased in TNF(0/0)mice as compared to WT animals. In addition, resolution of i.c. infiltrates was delayed in TNF(0/0)mice correlating with reduced apoptosis of inflammatory leukocytes and formation of a fibrous abscess capsule. Collectively, these data demonstrate that TNF is of key importance for the control of S. aureus-induced brain abscess and regulates the ensuing host immune response.

Brain abscess due to Nocardia otitidiscaviarum: report of a case and review

We present a case of brain abscess caused by Nocardia otitidiscaviarum in an immunocompromized 44-y-old male. Only 7 other cases of N. otitidiscaviarum brain abscess or involvement were found in the literature. The mortality was 75% despite treatment among cases reviewed. There is a lack of therapeutic guidelines regarding brain abscesses due to Nocardia.

Persistent immune activation associated with a mouse model of Staphylococcus aureus-induced experimental brain abscess

We have established a mouse experimental brain abscess model using Staphylococcus aureus where lesion sites are greatly exaggerated compared to the localized area of initial infection, reminiscent of an overactive immune response. Here we demonstrate the prolonged expression of IL-1 beta, TNF-alpha, and macrophage inflammatory protein-2 (MIP-2/CXCL2), concomitant with a chronic disruption of the blood-brain barrier (BBB) in mice with S. aureus-induced brain abscess. These changes correlated with the continued presence of infiltrating neutrophils and macrophages/microglia. Collectively these findings suggest that the excessive tissue damage that often results from brain abscess may be mediated, in part, by the perpetuation of antibacterial immune responses that are not downregulated in a timely manner.

IL-1 and TNF-α Play a Pivotal Role in the Host Immune Response in a Mouse Model ofStaphylococcus aureus-Induced Experimental Brain Abscess

Brain abscesses represent a significant medical problem despite recent advances made in detection and therapy. Using an established Staphylococcus aureus-induced brain abscess model, we have sought to define the functional importance of interleukin-1 (IL-1), tumor necrosis factor-alpha (TNF-alpha), and IL-6 in the host anti-bacterial immune response using cytokine gene knockout (KO) mice. Previous studies from our laboratory revealed that these cytokines are among the main proinflammatory mediators produced during the acute stage of brain abscess development. The results presented here demonstrate that although they share many redundant activities, IL-1 and TNF-alpha are important for containing bacterial infection in evolving brain abscesses as evident by increased mortality and bacterial burdens in IL-1 and TNF-alpha KO mice compared to wild type (WT) animals. In contrast, IL-6 was not found to be a major contributor to the host anti-bacterial immune response. Microarray analysis was used to evaluate the downstream consequences originating from the lack of IL-1 on subsequent proinflammatory mediator expression in brain abscesses from IL-1 KO and WT animals. Although numerous genes were significantly induced following S. aureus infection, only IL-1beta and 2 chemokines, CCL9 (macrophage inflammatory protein-1 gamma/MIP-1gamma) and CXCL13 (B lymphocyte chemoattractant/BLC), were differentially regulated in IL-1 KO versus WT animals. These results suggest that IL-1 and TNF-alpha play a pivotal role during the acute stage of brain abscess development through regulating the ensuing anti-bacterial inflammatory response.

[Severe Legionnaire's disease revealing an invasive aspergillosis in an apparently immunocompetent patient]

INTRODUCTION

Invasive aspergillosis, a sever disease, usually occurs in immuno-depressed patients. However, it may also develop in presumably immuno-competent patients.

OBSERVATION

A 54-year-old man, smoker, was hospitalised for hypoxemia of the right lung and septic shock, rapidly requiring mechanical ventilation combined with administration of vasopressors, and followed by dialysis because of the rapid worsening of an acute kidney failure. The diagnosis of pulmonary Legionnaire's disease was made on the second day in view of the positivity of the urinary legionella antigen. The progression of the disease was marked by the discovery of a histologically documented gastric aspergillosis and three abscessed intracerebral lesions within the context of a strongly positive aspergillus antigenemia. The disease worsened and the patient died on D 17, despite the antibiotic and anti-aspergillus treatments, haemodynamic support and dialysis.

DISCUSSION

To our knowledge, the association of invasive aspergillosis and severe Legionnaire's disease has never been described in an presumably immunocompetent patient. This clinical case suggests the existence, other than the usual risk factors of invasive aspergillosis that characterise profound states of immunodepression, of more subtle alterations in the immune system that may enhance this type of infection.

Primary brain abscess with Nocardia farcinica in an immunocompetent patient

In this paper, we describe a case of an immunocompetent patient with cerebral nocardiosis. The onset was with loss of strength, paresthesia and focal epilepsy of the left arm. MRI showed on T2-weighted sequences a hyperintense central area of pus surrounded by a well-defined hypointense capsule and surrounding edema; on T1-weighted sequences a hypointense necrotic cavity with ring enhancement following administration of intravenous gadolinium. The patient underwent surgical excision of the abscess but culture from the specimen was negative. After 40 days of empirical antimicrobial therapy he developed neurological deterioration with focal epilepsy. A new MRI documented an enlargement of the hypointense lesion in the right frontal-parietal region. A second craniotomy with drainage of the abscess was performed; cultures yielded Nocardia farcinica. Therapy with trimethoprim/sulfamethoxazole, amikacin and meropenem was given for 35 days, and clinical and radiological improvement was observed. Home therapy was done with oral trimethoprim/sulfamethoxazole. Currently, 5 months from the second surgery, the patient can walk with support and no new episodes of epilepsy occurred. Side effects were absent from therapy. The MRI appearance of the brain lesion has improved, with a decrease in size, surrounding edema and ring enhancement.

Intramedullary abscess resulting from disseminated cryptococcosis despite immune restoration in a patient with AIDS

We report on a case of cryptococcal intramedullary abscess, which occurred three years after a disseminated cryptococcosis and two years after a lymph node cryptococcal recurrence in a HIV-infected patient who exhibited a long-standing immune restoration. At the time of diagnosis, CD4(+) lymphocyte-count was 640x10(6)/l and HIV viral load was undetectable. Spinal involvement is rare during cryptococcosis of the central nervous system. As far as we are aware, there is only one case of proven intramedullary cryptococcal abscess reported in the literature and this case is then the second one. The significant and sustained increase in CD4 count following effective antiretroviral therapy was probably associated with only a partial immune restitution that did not allow to avoid the occurrence of the cryptococcal medullar abscess. Finally, this case raises the question of when to stop secondary prophylaxis of cryptococcal disease after increase in CD4 cell count under antiretroviral therapy.

Fatal Mycobacterium tuberculosis brain abscess in an immunocompetent patient

A non-HIV-infected 63-y-old woman presented seizures and coma during the course of Mycobacterium tuberculosis infection. Computerized tomography scan led to the diagnosis of a large compressive brain abscess. The patient died with multiorgan failure. Systematic central nervous system investigations should be done in cases of disseminated tuberculosis.

Potential role of human brain microvascular endothelial cells in the pathogenesis of brain abscess: inhibition of Staphylococcus aureus by activation of indoleamine 2,3-dioxygenase

Cerebral abscess is a rare complication of staphylococcal septicemia in infants associated with high mortality and morbidity. In the pathogenesis of abscess formation, S. aureus, one major causative agent, interacts with endothelial cells of the brain vessels before reaching the central nervous system. This study examined the growth of S. aureus in human brain microvascular endothelial cells (HBMEC) cultures stimulated with cytokines. IFN-gamma inhibited S. aureus replication by the induction of indoleamine 2,3-dioxygenase (IDO) in HBMEC. This activation of IDO in HBMEC could be shown by RT-PCR and by detection of kynurenine in culture supernatants of activated cells. Resupplementation of L-tryptophan abrogated the inhibitory effect of IFN-gamma on the growth of staphylococci, hence confirming the activation of indoleamine 2,3-dioxygenase as being responsible for the induced bacteriostasis. Addition of TNF-alpha enhanced the IFN-gamma mediated antibacterial effects, whereas TNF-alpha alone had no influence on staphylococcal growth. Stimulation of HBMEC with IFN-gamma failed to activate inducible nitric oxide synthase (iNOS) and subsequent production of nitric oxide (NO). Thus, intra- and extracellular depletion of L-tryptophan seems to be an important process in the defense against staphylococcal brain abscesses by means of creating an unfavorable microenvironment.

CXC chemokine receptor-2 ligands are required for neutrophil-mediated host defense in experimental brain abscesses

We have developed a mouse brain abscess model by using Staphylococcus aureus, one of the main etiologic agents of brain abscesses in humans. Direct damage to the blood-brain barrier was observed from 24 h to 7 days after S. aureus exposure as demonstrated by the accumulation of serum IgG in the brain parenchyma. Evaluation of brain abscesses by immunohistochemistry and flow cytometry revealed a prominent neutrophil infiltrate. To address the importance of neutrophils in the early containment of S. aureus infection in the brain, mice were transiently depleted of neutrophils before implantation of bacteria-laden beads. Neutrophil-depleted animals consistently demonstrated more severe brain abscesses and higher CNS bacterial burdens compared with control animals. S. aureus led to the induction of numerous chemokines in the brain, including macrophage-inflammatory protein (MIP)-1alpha/CCL3, MIP-1beta/CCL4, MIP-2/CXCL1, monocyte chemoattractant protein-1/CCL2, and TCA-3/CCL1, within 6 h after bacterial exposure. These chemokines also were expressed by both primary cultures of neonatal mouse microglia and astrocytes exposed to heat-inactivated S. aureus in vitro. Because neutrophils constitute the majority of the cellular infiltrate in early brain abscess development, subsequent analysis focused on MIP-2 and KC/CXCL1, two neutrophil-attracting CXC chemokines. Both MIP-2 and KC protein levels were significantly elevated in the brain after S. aureus exposure. Neutrophil extravasation into the brain parenchyma was impaired in CXCR2 knockout mice and was associated with increased bacterial burdens. These studies demonstrate the importance of the CXCR2 ligands MIP-2 and KC and neutrophils in the acute host response to S. aureus in the brain.

[Brain abscess caused by Nocardia sp in immunosuppressed patient]

Patient with autoimmune haemolytic anaemia and thrombocytopenic purpura (Evans Syndrome), treated with immunosuppressive therapy (prednisone and azathioprine) developed brain abscess unresponsive to antimicrobial therapy, in spite of its 23 days duration. Diagnosis could be possible after recover secretion of peribulbar abscess and maintenance of this material over seven days in incubation.

Chronic invasive aspergillosis in apparently immunocompetent hosts

Seventeen cases of invasive aspergillosis occurring since 1987 in apparently immunologically normal hosts have been reviewed: 9 of invasive sinus aspergillosis, 2 of isolated brain abscesses, 3 of pneumonia (1 in a patient who developed mediastinitis), 2 of lymph node aspergillosis, and 1 of osteomyelitis of the foot. Two of the 9 patients with sinus aspergillosis died; the rest were stable up to March 1993. They responded initially to combined surgical and medical therapy. Both patients with brain abscesses survived following surgery, but one had neurological sequelae. Both patients with pneumonia were well following therapy with amphotericin B; one also received itraconazole. The patient with mediastinitis died, but this disease was diagnosed late. The patients with lymph node involvement were lost to follow-up, as was the patient with osteomyelitis. Invasive aspergillosis may be common in Pakistan. Greater awareness would allow earlier diagnosis and therapy, thereby improving the outcome.

Brain abscess in solid organ transplant recipients receiving cyclosporine-based immunosuppression

OBJECTIVE

To determine the incidence, clinical presentation, and outcome and confounding factors associated with the development of a brain abscess in solid organ transplant recipients.

DESIGN

A 14-year retrospective survey.

SETTING

A single, multiorgan, academic transplantation center.

PATIENTS

A total of 2380 liver transplant recipients, 1650 kidney transplant recipients, and 598 heart, heart-lung, or lung transplant recipients of all ages (pediatric and adult) were included. All patients were given cyclosporine-based immunosuppression during this period.

MAIN OUTCOME MEASURE

A brain abscess was determined to be present it there was histological and/or microbiological confirmation of a brain lesion seen by a computed tomographic scan. A brain abscess was considered suspicious if radiographic findings were seen in the clinical setting of neurologic symptoms and fever without histological or microbiological confirmation.

RESULTS

A brain abscess developed in a total of 28 patients (0.61%) of the total study population. The frequency of brain abscess according to organ type was as follows: 0.63%, liver; 0.36%, kidney; and 1.17%, heart and heart-lung. The overall mortality was 86%. Complicating factors associated with fungal (Candida and Aspergillus sp) abscess formation included major subsequent operations, retransplantations, antirejection therapy, associated bacteremia or viremia, and multiorgan failure. The lung was the primary site of dissemination in 18 patients. Low-dose prophylactic amphotericin was ineffective in preventing a fungal brain abscess in 10 high-risk patients. Because of the ineffective therapy and the deadly nature of established fungal abscesses, full-dose antifungal therapy and reduced immunosuppression were warranted on identification of a high-risk clinical setting. Nonfungal abscesses (Nocardia and Toxoplasma sp) occurred in healthy graft recipients long after transplantation. The existing medical therapy is usually effective in these patients, provided that rapid tissue diagnosis is established.

CONCLUSIONS

The epidemiological features of brain abscess formation after solid organ transplantation suggest 2 populations of patients exist that differ in timing, clinical setting, and response to therapy. For the chronically immunosuppressed outpatient, an established abscess should be empirically treated with sulfonamides until tissue diagnosis is confirmed. On the other hand, the acutely immunosuppressed posttransplant recipient, with defined risk factors, should receive full-dose therapy with amphotericin B and concomitantly lowered immunosuppression.

Gordona terrae central nervous system infection in an immunocompetent patient

The bacterial genus Gordona includes seven species of mycolic acid-containing actinomycetes which are cultured from environmental sources and rarely from clinical samples. They have been implicated in primary pulmonary diseases, nosocomial wound infections, and central nervous system infections in two immunocompromised patients. We isolated Gordona terrae from the cerebrospinal fluid sample of an immunocompetent patient with meningitis and multiple brain abscesses and detected Gordona terrae DNA in the abscesses. The outcome was good at the 4-year follow-up, after prolonged treatment with trimethoprim-sulfamethoxazole. Phenotypic identification of this isolate was confirmed by analysis of the 16S rRNA gene sequence, which shared 100% homology with that of G. terrae reference strains. Physicians and clinical microbiologists must be aware of the occurrence of Gordona species infection not only among immunocompromised patients but among all patients. Accurate identification of Gordona species may be accomplished by molecular techniques.

Aspergillus brain abscess in a patient with normal immunity--case report

A 53-year-old male with normal immunity presented with Aspergillus brain abscess manifesting as frontal headache. T2-weighted magnetic resonance imaging revealed a hypointense lesion in the left frontal lobe extending into the right frontal lobe. The hypointense appearance on T2-weighted images appears to be characteristic of aspergillosis. Bifrontal craniotomy exposed an elastic-hard mass in the base of the left frontal lobe extending into the right frontal lobe, and into the left ethmoid sinus. The mass contained a cavity with white fluid. The abscess was removed almost totally. The histological diagnosis was Aspergillus abscess. Antibiotic treatment with amphotericin B and fluconazole was given for 2 months postoperatively. No recurrence was identified during 15-month follow-up.

Sterile abscesses in glioma patients treated by intraparenchymal injection of lymphokine-activated killer cells and recombinant interleukin-2: case reports

Earlier, we conducted Phase I clinical trials to determine any acute toxicity of adoptive immunotherapy with intralesional injections of autologous lymphocytes expressing lymphokine-activated killer (LAK) activity and recombinant interleukin-2 (rIL-2) in patients with malignant glioma. Within six weeks of craniotomy and intralesional injection of autologous LAK cells plus rIL-2, 3 of 29 patients demonstrated a decline in clinical status and evidence on computed tomographic and magnetic resonance imaging scans of edema and mass of unknown character at the site of previous surgery and immunotherapy. Craniotomy was performed to remove the tissue and reduce intracranial pressure. Microscopic examination of the excised material indicated no new tumor growth within the resected mass, but rather that the tissue had the histological characteristics of a chronic sterile abscess including necrosis, fibrosis, and influx of inflammatory cells. Factors that may have contributed to this reaction in the 3 patients were age, Karnofsky score, the extent of tumor excision, and immune status. All 3 had also been treated with greater than average numbers of rIL-2 activated lymphocytes that demonstrated significant in vitro LAK activity. The results suggest that in patients whose clinical status is good and who are not immunosuppressed by corticosteroids, the dose-limiting toxicity of intraparenchymal immunotherapy with LAK cells plus rIL-2 for glioma may be related to the total, absolute number of activated cells injected, and this toxicity develops over time and is manifested by development of a sterile abscess.

[The role of the immune system in the development of rhinosinusogenous intracranial complications (abscess, arachnoiditis)]

The article analyses the results of some modern immunological methods of examination in 49 patients with various rhinosinusogenous intracranial complications. It was found that secondary immunodeficiency develops in this group of patients, which is often attended with an autoimmune component. Both the nonspecific defence factors and the organism's specific immune response are impaired in this case. There was a direct relationship between the depth of the immunity disorders and the severity of the clinical course of the disease. The results obtained may be used as auxiliary and prognostic criteria in appraising the patients' condition. The results of the study indicate that rhinosinusogenous intracranial complications should be managed by pathogenetically substantiated therapy with the use of immunocorrective agents in a complex with other types of treatment.

Cerebral scintigraphy with 111indium oxine-labelled leukocytes in the differential diagnosis of intracerebral cystic lesions

CT scanning and scintigraphy with 111Indium-oxide-labelled white blood cells were used to study 32 cases of intracerebral cystic lesions. The results and the criteria of positivity used to lower the false positive rate are discussed. A new criterion, designed to assess the time course of the scintiscan and so reduce still further the frequency of false positives is put forward.

Brain abscess due to Listeria monocytogenes: case report and literature review

Listeria monocytogenes is an uncommon cause of brain abscess. Of a total of 14 cases of L. monocytogenes brain abscess (one described for the first time and 13 reported previously in the English-language literature), seven (50%) occurred in patients with leukemia and recipients of renal transplants; four (29%) of the cases occurred in previously healthy individuals. Common clinical findings were similar to those in brain abscess due to other causes and included fever (57%), headache (57%), and focal neurologic signs (64%). Distinctive, however, was the unusually high frequency of associated meningitis and bacteremia; blood cultures were positive in all eight cases in which they were performed. Eight (57%) of the 14 patients died. L. monocytogenes should be included in the differential diagnosis of brain abscess in patients with leukemia and in renal transplant recipients. Listerial brain abscess is highly unlikely when blood culture results are negative.

Expression of class II major histocompatibility antigens on reactive astrocytes and endothelial cells within the gliosis surrounding metastases and abscesses

To pursue the hypothesis that astrocytes may function as immunoregulatory cells, astrocytes within the reactive gliosis surrounding metastases and abscesses were examined for the expression of the class II major histocompatibility antigen HLA-DR. The tissue was analysed using single- and double-label avidin-biotin immunoperoxidase techniques employing monoclonal antibodies for HLA-DR (D1-12), macrophages (anti-Fc), T lymphocytes (2D3), glial fibrillary acidic protein (GFAP) and GFAP antiserum. Macrophages, astrocytes and T lymphocytes were present. The double label demonstrated HLA-DR on a large number of astrocytes. Taken together with evidence that astrocytes can release interleukin-1 and can present an antigen to lymphocytes, the finding of HLA-DR on these astrocytes supports their possible involvement in the cellular immune response.

Immune response to Bacteroides ureolyticus in a patient with brain abscess

A high titer (1:256) of agglutinating antibodies against Bacteroides ureolyticus was demonstrated in a 35-year-old woman with brain abscess, using a microagglutination test. Tests done with B. ureolyticus and heterologous sera as well as with heterologous strains and the patient's serum were negative. Circulating antibody to B. ureolyticus has not been reported previously.

Acquired immunodeficiency with intestinal cryptosporidiosis: possible transmission by Haitian whole blood

A 31-year-old Frenchman had an acquired immunodeficiency syndrome (AIDS) with profound depression of cellular immunity and relative sparing of humoral immunity. The clinical picture included intractable secretory diarrhoea, vomiting, abdominal pain, and weight loss. Gastrointestinal cryptosporidiosis was present and a perfusion technique showed profuse secretion of fluid in the proximal small bowel. The patient also had recurrent Salmonella typhimurium septicaemia, cytomegalovirus infection, and cerebral toxoplasmosis and he died within 13 months. This patient did not belong to any of the groups known to be affected by this type of acquired immunodeficiency (homosexuals, drug addicts, haemophiliacs, Haitians) but had been transfused with Haitian blood 4 years before onset of symptoms. This case supports the notion that some forms of AIDS may be transmitted by blood, with a long incubation period.

Brain abscess due to Nocardia caviae. Report of a fatal outcome associated with abnormal phagocyte function

Nocardia is an uncommon cause of human disease. We report a patient with a fatal brain abscess who had abnormal phagocyte function as measured by neutrophile chemotaxis, adherence, phagocytic function, and chemiluminescence in vitro and by Rebuck skin window in vivo. Antimicrobial agar dilution susceptibility suggested minocycline was more active than sulfamethoxazole.

Hypogammaglobulinemia and Nocardia brain abscesses

The host defense responses to Nocardia asteroides are not known. We have investigated a patient with common variable adult onset hypogammaglobulinemia who developed fatal disseminated nocardiosis. The patient had low levels of serum immunoglobulins; the total lymphocyte count was normal as were the percentages of circulating T and B cells. Transmission electron microscopic studies demonstrated typical N. asteroides within the brain parenchyma and nonspecific inflammatory changes in the central nervous system. The findings suggest that humoral immunity may play a major role in the host defense of patients with this disease.

Immunologic characterization of cerebrospinal fluid lymphocytes: preliminary report

Cellular immunocompetence of cerebrospinal fluid lymphocytes was investigated in several neurologic diseases. Microtechniques were developed to enable determination of E-rosetting capacity and phytohemagglutinin responsiveness of scant numbers of cells present in the cerebrospinal fluid specimens studied. Although most individuals had phytohemagglutinin-responsive cells in their CSF, reactivity was somewhat less than that found simultaneously in their blood. Three of eight patients had comparable percentages of E rosettes in their blood and CSF. Int the remainder, the values differed significantly. Although preliminary, these result illustrate a new approach to immunologic characterization of CSF lymphocytes in diseases.

Brain abscess

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