Gasdermin-D-dependent IL-1α release from microglia promotes protective immunity during chronic Toxoplasma gondii infection.

Microglia, resident immune cells of the CNS, are thought to defend against infections. Toxoplasma gondii is an opportunistic infection that can cause severe neurological disease. Here we report that during T. gondii infection a strong NF-κB and inflammatory cytokine transcriptional signature is overrepresented in blood-derived macrophages versus microglia. Interestingly, IL-1α is enriched in microglia and IL-1ß in macrophages. We find that mice lacking IL-1R1 or IL-1α, but not IL-1ß, have impaired parasite control and immune cell infiltration within the brain. Further, we show that microglia, not peripheral myeloid cells, release IL-1α ex vivo. Finally, we show that ex vivo IL-1α release is gasdermin-D dependent, and that gasdermin-D and caspase-1/11 deficient mice show deficits in brain inflammation and parasite control. These results demonstrate that microglia and macrophages are differently equipped to propagate inflammation, and that in chronic T. gondii infection, microglia can release the alarmin IL-1α, promoting neuroinflammation and parasite control.

Human extracellular vesicles and correlation with two clinical forms of toxoplasmosis.

AIM: This study analyzed microvesicles and exosomes, called as extracellular vesicles (EVs) excreted in serum and cerebrospinal fluid (CSF) from patients with cerebral or gestational toxoplasmosis. METHODS: Clinical samples from 83 individuals were divided into four groups. Group I, 20 sera from healthy individuals and pregnant women (seronegative for toxoplasmosis); group II, 21 sera from seropositive patients for toxoplasmosis (cerebral or gestational forms); group III, 26 CSF samples from patients with cerebral toxoplasmosis/HIV co-infection (CT/HIV) (seropositive for toxoplasmosis); and group IV, 16 CSF samples from seronegative patients for toxoplasmosis, but with HIV infection and other opportunistic infections (OI/HIV). Serum and CSF samples were ultracentrifuged to recover EVs. Next, vesicle size and concentration were characterized by Nanoparticle Tracking Analysis (NTA). RESULTS: Concentrations of serum-derived EVs from toxoplasmosis patients (mean: 2.4 x 1010 EVs/mL) were statically higher than of non-infected individuals (mean: 5.9 x 109 EVs/mL). Concentrations of CSF-derived EVs were almost similar in both groups. CT/HIV (mean: 2.9 x 109 EVs/mL) and OI/HIV (mean: 4.8 x 109 EVs/mL). Analyses by NTA confirmed that CSF-derived EVs and serum-derived EVs had size and shape similar to microvesicles and exosomes. The mean size of EVs was similar in serum and CSF. Thus, the concentration, and not size was able distinguish patients with toxoplasmosis than healthy individuals. Presence of exosomes was also confirmed by transmission electron microscopy and evidence of tetraspanins CD63 and CD9 in immunoblotting. Relative expressions of miR-146a-5p, miR-155-5p, miR-21-5p, miR-29c-3p and miR-125b-5p were estimated in exosomal miRNA extracted of EVs. Serum-derived EVs from group II (cerebral and gestational toxoplasmosis) up-expressed miR-125b-5p and miR-146a-5p. CSF-derived EVs from CT/HIV patients) up-expressed miR-155-5p and miR-21-5p and were unable to express miR-29c-3p. CONCLUSION: These data suggest the participation of EVs and exosomal miRNAs in unbalance of immune response as elevation of TNF-α, IL-6; and downregulation of IFN-γ in cerebral and gestational forms of toxoplasmosis.

Plasma extracellular microRNAs are related to AIDS/cerebral toxoplasmosis co-infection.

This study investigated the potential of five miRNA candidates for cerebral toxoplasmosis/HIV co-infection (CT/HIV) biomarkers. miR-155-5p, miR-146a-5p, miR-21-5p, miR-125b-5p and miR-29c-3p were tested in 79 plasma divided into groups: 32 CT/HIV patients; 27 individuals with asymptomatic toxoplasmosis (AT); and 20 individuals seronegative for toxoplasmosis (NC). From each was collected peripheral blood/EDTA for laboratory diagnosis. Blood cells for DNA extractions (molecular diagnosis), plasma for RNA extractions (gene expression) and ELISA (serological diagnosis). miRNA expression was performed by qPCR, and values were expressed in Relative Quantification (RQ). Among the five miRNAs, miR-21-5p and miR-146a-5p were up-expressed in CT/HIV group when compared with AT and NC groups. RQ means for miR-21-5p and miR-146a-5p in CT/HIV group were 3.829 and 2.500, while in AT group, were 1.815 and 1.661, respectively. Differences between 3 groups were statistically significant (Kruskal-Wallis ANOVA test), as well as CT/HIV and AT groups (Mann-Whitney test). Plasma of CT/HIV and AT groups expressed similar levels of miR-29c-3p, miR-155-5p and miR-125b-5p. As NC group was different of CT/HIV and AT groups, differences between three groups were statistically significant (Kruskal-Wallis ANOVA test). No difference was shown between CT/HIV and AT groups (Mann-Whitney test). These results suggest the host miRNAs modulation by Toxoplasma gondii.

Impact of Engineered Expression of Mitochondrial Association Factor 1b on Toxoplasma gondii Infection and the Host Response in a Mouse Model.

The opportunistic intracellular parasite Toxoplasma gondii causes a lifelong chronic infection capable of reactivating in immunocompromised individuals, which can lead to life-threatening complications. Following invasion of the host cell, host mitochondria associate with the parasitophorous vacuole membrane. This phenotype is T. gondii strain specific and is mediated by expression of a host mitochondrial association-competent (HMA+) paralog of the parasite protein mitochondrial association factor 1 (MAF1b). Previous work demonstrated that expression of MAF1b in strains that do not normally associate with host mitochondria increases their fitness during acute infection in vivo However, the impact of MAF1b expression during chronic T. gondii infection is unclear. In this study, we assess the impact of MAF1b expression on cyst formation and cytokine production in mice. Despite generally low numbers of cysts generated by the in vitro culture-adapted strains used in this study, we find that parasites expressing MAF1b have higher numbers of cysts in the brains of chronically infected mice and that MAF1b+ cyst burden significantly increases during the course of chronic infection. Consistent with this, mice infected with MAF1b+ parasites have higher levels of the serum cytokines RANTES and VEGF (vascular endothelial growth factor) at day 57 postinfection, although this could be due to higher parasite burden at this time point rather than direct manipulation of these cytokines by MAF1b. Overall these data indicate that MAF1b expression may also be important in determining infection outcome during the chronic phase, either by directly altering the cytokine/signaling environment or by increasing proliferation during the acute and/or chronic phase.IMPORTANCE The parasite Toxoplasma gondii currently infects approximately one-third of the world's population and causes life-threatening toxoplasmosis in individuals with undeveloped or weakened immune systems. Current treatments are unable to cure T. gondii infection, leaving infected individuals with slow-growing tissue cysts for the remainder of their lives. Previous work has shown that expression of the parasite protein mitochondrial association factor 1 (MAF1b) is responsible for the association of T. gondii parasites with host mitochondria and provides a selective advantage during acute infection. Here we examine the impact of MAF1b expression during chronic T. gondii infection. We find that mice infected with MAF1b-expressing parasites have higher cyst burden and cytokine levels than their wild-type counterparts. A better understanding of the genes involved in establishing and maintaining chronic infection will aid in discovering effective therapeutics for chronically infected individuals.

Impact of alternative treatment approach for cerebral toxoplasmosis among HIV/AIDS patients from a resource-poor setting in Burkina Faso

Cerebral toxoplasmosis is caused by the protozoan Toxoplasma gondii because of reactivation of latent tissue cysts in the Acquired Immunodeficiency Syndrome (AIDS) patients with severe immunosuppression. The objective of this study was to evaluate the benefit of co-trimoxazole in presumptive and prevention of cerebral toxoplasmosis in Human Immunodeficiency Virus (HIV)/AIDS patients at Bobo-Dioulasso Hospital in Burkina Faso from June 2012 to October 2014. ELISA and ELFA were performed on serum for the quantitative determination of IgG and IgM anti-T. gondii, respectively. The seroprevalence of toxoplasmosis was 29.3%. No IgM antibodies for T. gondii were found. Six patients with Toxoplasma-specific antibodies presented cerebral toxoplasmosis. All patients were infected by HIV-1 with the median of CD4+ T lymphocytes at 141 cells/µl. No patient was under antiretroviral therapy. No case of cerebral toxoplasmosis was noted in patients receiving co-trimoxazole in prevention. Presumptive treatment of cerebral toxoplasmosis with co-trimoxazole was effective in all patients with a significant clinical improvement in 83.3%. These results attest the benefit of cotrimoxazole in cerebral toxoplasmosis treatment in countries where drug resources are limited when sulfadiazine is not available. Ours finding highlight the importance of establishing toxoplasmosis chemoprophylaxis to HIV with severe immunosuppression patients and positive Toxoplasma serology.

Cerebral toxoplasmosis in an MS patient receiving Fingolimod.

Multiple Sclerosis (MS) is an autoimmune disease in which lymphocytes target putative myelin antigens in the CNS, causing inflammation and neurodegeneration. Fingolimod (FTY720) is an immunosuppressive drug used as a second line therapy for relapsing forms of MS due to its safety profile and good response to treatment. Despite its safety, there are still concerns about the possibility of Fingolimod being linked to the development of opportunistic infections like disseminated varicella zoster infections and herpes simplex encephalitis. In this case report, we describe one patient with past medical history of MS in current treatment with Fingolimod for the last year which presents herself with hemiparesis, fever and fatigue. The initial MRI showed multiple demyelinating-like lesions that could have corresponded to the tumefactive form of MS relapse. The blood work up revealed leukopenia with lymphopenia and a CD4+ count of 200 cell/mm3. Treatment for acute relapse was initiated with little to no response. Further examination was carried by the clinicians, a lumbar puncture was performed and it showed pleocytosis with increased protein levels. Later, several serologic studies were performed and both IgM and IgG antibodies for Toxoplasma were positive. Diagnosis of cerebral toxoplasmosis was made and there was no evidence of HIV infection or other causes of secondary immunodeficiency in this patient, except the use of fingolimod. Evidence of decreased levels of CD4+ due to Fingolimod use is concerning. The risk of opportunistic infections in these patients must be considered in order to start or continue therapy with these agents. Further studies are needed to determine the percentage of the population at risk of immunosuppression and its long-term consequences as well as new actions to prevent infections.

Performance Testing of PCR Assay in Blood Samples for the Diagnosis of Toxoplasmic Encephalitis in AIDS Patients from the French Departments of America and Genetic Diversity of Toxoplasma gondii: A Prospective and Multicentric Study.

BACKGROUND: Toxoplasmic encephalitis in patients with AIDS is a life-threatening disease mostly due to reactivation of Toxoplasma gondii cysts in the brain. The main objective of this study was to evaluate the performance of real-time PCR assay in peripheral blood samples for the diagnosis of toxoplasmic encephalitis in AIDS patients in the French West Indies and Guiana. METHODOLOGY/PRINCIPAL FINDINGS: Adult patients with HIV and suspicion of toxoplasmic encephalitis with start of specific antitoxoplasmic therapy were included in this study during 40 months. The real-time PCR assay targeting the 529 bp repeat region of T. gondii was performed in two different centers for all blood samples. A Neighbor-Joining tree was reconstructed from microsatellite data to examine the relationships between strains from human cases of toxoplasmosis in South America and the Caribbean. A total of 44 cases were validated by a committee of experts, including 36 cases with toxoplasmic encephalitis. The specificity of the PCR assay in blood samples was 100% but the sensitivity was only 25% with moderate agreement between the two centers. Altered level of consciousness and being born in the French West Indies and Guiana were the only two variables that were associated with significantly decreased risk of false negative results with the PCR assay. CONCLUSION/SIGNIFICANCE: Our results showed that PCR sensitivity in blood samples increased with severity of toxoplasmic encephalitis in AIDS patients. Geographic origin of patients was likely to influence PCR sensitivity but there was little evidence that it was caused by differences in T. gondii strains. TRIAL REGISTRATION: ClinicalTrials.gov NCT00803621.

Toxoplasmic encephalitis: role of Human Leucocyte Antigens/alleles associated with rapid progression to Acquired Immunodeficiency Syndrome

Abstract Background/aims The frequency of Human Leucocyte Antigens/alleles associated with rapid progression from Human Immunodeficiency Virus infection to Acquired Immunodeficiency Syndrome was evaluated in Brazilian patients with Acquired Immunodeficiency Syndrome with and without Toxoplasmic Encephalitis. Methods 114 patients with Acquired Immunodeficiency Syndrome (41 with Toxoplasmic Encephalitis, 43 with anti-Toxoplasma gondii antibodies, without Toxoplasmic Eencephalitis, and 30 without anti-Toxoplasma gondii antibodies circulating and without Toxoplasmic Encephalitis) were studied. Results Human Leucocyte Antigens/alleles associated with rapid progression to Acquired Immunodeficiency Syndrome, particularly HLA-B35, -DR3, and -DR1 allele group, were significantly less represented in patients with Toxoplasmic Encephalitis and Acquired Immunodeficiency Syndrome. Conclusion The presence of these Human Leucocyte Antigens/Alleles that predispose to Acquired Immunodeficiency Syndrome progression was associated with resistance to Toxoplasmic Encephalitis among Human Immunodeficiency Virus-1 carriers.

Characteristic Cytokine and Chemokine Profiles in Encephalitis of Infectious, Immune-Mediated, and Unknown Aetiology.

BACKGROUND: Encephalitis is parenchymal brain inflammation due to infectious or immune-mediated processes. However, in 15-60% the cause remains unknown. This study aimed to determine if the cytokine/chemokine-mediated host response can distinguish infectious from immune-mediated cases, and whether this may give a clue to aetiology in those of unknown cause. METHODS: We measured 38 mediators in serum and cerebrospinal fluid (CSF) of patients from the Health Protection Agency Encephalitis Study. Of serum from 78 patients, 38 had infectious, 20 immune-mediated, and 20 unknown aetiology. Of CSF from 37 patients, 20 had infectious, nine immune-mediated and eight unknown aetiology. RESULTS: Heat-map analysis of CSF mediator interactions was different for infectious and immune-mediated cases, and that of the unknown aetiology group was similar to the infectious pattern. Higher myeloperoxidase (MPO) concentrations were found in infectious than immune-mediated cases, in serum and CSF (p = 0.01 and p = 0.006). Serum MPO was also higher in unknown than immune-mediated cases (p = 0.03). Multivariate analysis selected serum MPO; classifying 31 (91%) as infectious (p = 0.008) and 17 (85%) as unknown (p = 0.009) as opposed to immune-mediated. CSF data also selected MPO classifying 11 (85%) as infectious as opposed to immune-mediated (p = 0.036). CSF neutrophils were detected in eight (62%) infective and one (14%) immune-mediated cases (p = 0.004); CSF MPO correlated with neutrophils (p<0.0001). CONCLUSIONS: Mediator profiles of infectious aetiology differed from immune-mediated encephalitis; and those of unknown cause were similar to infectious cases, raising the hypothesis of a possible undiagnosed infectious cause. Particularly, neutrophils and MPO merit further investigation.

Hypernatremia in a Cat with Toxoplasma-Induced Panencephalitis.

A 12 yr old female neutered Carthusian crossbreed cat was presented due to progressive neurological signs. Clinical signs included dehydration, stupor, and anisocoria. Laboratory examination revealed severe hypernatremia, azotemia, hyperglobulinemia, and an erythrocytosis. Clinical signs and hypernatremia suggested an intracranial process. Imaging studies revealed a loss of structure in the cerebrum, hypothalamus, and pituitary gland. Due to a poor prognosis, the cat was euthanatized. Histopathological examination revealed a subacute granulomatous and necrotizing panencephalitis with Toxoplasma-typical protozoa. The Toxoplasma-induced dysfunction of the hypothalamus and pituitary gland led to diabetes insipidus, which was, in combination with insufficient water intake, the most likely cause for the hypernatremia.

Evolution of cytokine profile during the treatment of cerebral toxoplasmosis in HIV-infected patients.

This study was to follow IFN-γ, TNF-α and IL-10 modulation of peripheral blood mononuclear cells (PBMC) from HIV/cerebral toxoplasmosis patients (CT) during specific treatment. The results were compared with two other groups: HIV patients that had CT at least one year before (P/CT) and individuals with chronic toxoplasmosis (CHR). Blood samples (63) collected from three groups were analyzed. CT, 15 patients (3 blood samples collected one day before Toxoplasma gondii treatment; 7 and 15days during the treatment). P/CT, 5 patients (one blood sample collected at least, one year after the treatment). CHR, 13 individuals with chronic toxoplasmosis (one blood sample). Cytokine levels were assessed by ELISA after PBMC stimulation with T. gondii antigen. CT patients had low IFN-γ; discrete increase at 7th and 15th days; and the levels were recovered in cured patients (P/CT). CT patients had high TNF-α in the beginning of the treatment. TNF-α levels decrease during the treatment (7th and 15th) and in those patients who were treated (P/CT). IL-10 levels were almost similar in CT and P/CT groups but low when compared with CHR individuals. The evolution of the infection was correlated to restoration of IFN-γ response and a decrease of the inflammation. The evaluation of the immune response can provide valuable information and better monitoring of patients during specific treatment.

[Cerebral toxoplasmosis in the pattern of secondary CNS involvements in HIV-infected patients in the Russian federation: clinical and diagnostic features].

The incidence of cerebral toxoplasmosis (CT) among all brain involvements was determined in patients with Stage 4B HIV infection (AIDS) in 2003-2009. Clinical and laboratory parameters were estimated in 156 patients to reveal diagnostic criteria. As a result, CT was shown to be a leading cause of neurologic diseases in patients with late-stage HIV infection (34.7% of cases of brain involvement). In 11.5%, it took place as a generalized process. CT concurrent with cytomegalovirus infection, tuberculosis, or other secondary lesions was frequently diagnosed. Of importance in the diagnosis of CT are magnetic resonance imaging results in addition to basic, clinical data that can assume this diagnosis. The high and moderate serum concentrations of T.gondii IgG are of diagnostic value, which may be used as an auxiliary method to verify the diagnosis.

[Use of immunological and molecular biological methods to diagnose cerebral toxoplasmosis in HIV infection].

Cerebral toxoplasmosis is one of the leading causes of neurologic diseases with high mortality rates in patients with HIV infection. Invasion was difficult to diagnose for a number of objective reasons. The objective of the investigation was to determine the clinical sensitivity of different laboratory techniques as both a single study and their various combinations to verify the diagnosis of cerebral toxoplasmosis in HIV-infected patients. Blood and cerebrospinal fluid were tested in 51 patients with Stage 4B HIV infection (AIDS) with the verified diagnosis of cerebral toxoplasmosis. Separate determination of specific antibodies of IgG, IgM, IgA and toxoplasma DNA in the blood and cerebrospinal fluid was shown to have an insufficient clinical sensitivity (37.3-68.6%). The benefits of various combinations of immunological and molecular biological assays enhancing the diagnostic efficiency up to 76.5-96.1% are demonstrated.

[Toxoplasmosis in HIV infection: invasion reactivation criteria].

Contemporary representation of toxoplasmosis reactivation criteria in HIV infection is generalized. Significance of the issue is justified: toxoplasmosis is a leading neurological pathology in AIDS with a high lethality percentage due to complexity of clinical confirmation and difficulties of laboratory confirmation of the start of reactivation. Clinical, instrumental, immunologic, molecular genetic invasion reactivation criteria are discussed in the article and analysis of their effectiveness is performed; their most feasible combinations are justified. Further system analysis of the cerebral toxoplasmosis reactivation criteria specified in the article in combination with search of new pathogen dissemination markers will allow to obtain important information that has both fundamental interest and important practical significance.

Factors influencing cerebrospinal fluid and plasma HIV-1 RNA detection rate in patients with and without opportunistic neurological disease during the HAART era.

BACKGROUND: In the central nervous system, HIV replication can occur relatively independent of systemic infection, and intrathecal replication of HIV-1 has been observed in patients with HIV-related and opportunistic neurological diseases. The clinical usefulness of HIV-1 RNA detection in the cerebrospinal fluid (CSF) of patients with opportunistic neurological diseases, or the effect of opportunistic diseases on CSF HIV levels in patients under HAART has not been well defined. We quantified CSF and plasma viral load in HIV-infected patients with and without different active opportunistic neurological diseases, determined the characteristics that led to a higher detection rate of HIV RNA in CSF, and compared these two compartments. METHODS: A prospective study was conducted on 90 HIV-infected patients submitted to lumbar puncture as part of a work-up for suspected neurological disease. Seventy-one patients had active neurological diseases while the remaining 19 did not. RESULTS: HIV-1 RNA was quantified in 90 CSF and 70 plasma samples. The HIV-1 RNA detection rate in CSF was higher in patients with neurological diseases, in those with a CD4 count lower than 200 cells/mm3, and in those not receiving antiretroviral therapy, as well as in patients with detectable plasma HIV-1 RNA. Median viral load was lower in CSF than in plasma in the total population, in patients without neurological diseases, and in patients with toxoplasmic encephalitis, while no significant difference between the two compartments was observed for patients with cryptococcal meningitis and HIV-associated dementia. CSF viral load was lower in patients with cryptococcal meningitis and neurotoxoplasmosis under HAART than in those not receiving HAART. CONCLUSION: Detection of HIV-1 RNA in CSF was more frequent in patients with neurological disease, a CD4 count lower than 200 cells/mm3 and detectable plasma HIV-1. Median HIV-1 RNA levels were generally lower in CSF than in plasma but some patients showed higher CSF levels, and no difference between these two compartments was observed in patients with cryptococcal meningitis and HIV-associated dementia, suggesting the presence of intrathecal viral replication in these patients. HAART played a role in the control of CSF HIV levels even in patients with cryptococcal meningitis and neurotoxoplasmosis in whom viral replication is potentially higher.

Toxoplasmosis encephalitis following severe graft-vs.-host disease after allogeneic hematopoietic stem cell transplantation: 17 yr experience in Fukuoka BMT group.

Toxoplasmosis is a rare but rapidly fatal complication that can occur following hematopoietic stem cell transplantation (HSCT). Over a 17-yr period at our institutions, a definite diagnosis of toxoplasmosis was made in only two of 925 allogeneic HSCT recipients (0.22%) and none of 641 autologous HSCT recipients. These two patients received a conventional conditioning regimen followed by transplantation from an HLA-matched donor; however, they developed severe graft-vs.-host disease, which required intensive immunosuppressive therapy. Despite prophylactic treatment with trimethoprim/sulfamethoxazole, their immunosuppressive state, as indicated by a low CD4(+) cell count, might have resulted in toxoplasmosis encephalitis. Rapid and non-invasive methods such as a polymerase chain reaction (PCR) test of their cerebrospinal fluid for Toxoplasma gondii and magnetic resonance imaging of the brain were useful for providing a definitive diagnosis and prompt therapy in these patients: one patient stabilized and survived after responding to treatment with pyrimethamine/sulfodiazine whereas the other died of bacterial infection. In addition, retrospective PCR analyses of the frozen stored peripheral blood samples disclosed that detection of T. gondii preceded the onset of disease, indicating routine PCR testing of peripheral blood specimens may be an early diagnostic tool. It should be noted that when patients receiving HSCT have an unexplained fever and/or neurological complications, PCR tests should be considered to avoid cerebral lesions and improve the outcome of the patients.

Toxoplasma meningoencephalitis in HIV-seronegative patients: clinical patterns, imaging features and treatment outcome.

We evaluated the clinical and imaging features of cranial toxoplasmosis in patients without HIV infection. Between 1995 and 2005, 15 patients with serologically proven cranial toxoplasmosis were selected for clinical and imaging study from 233 patients with chronic meningitis and 364 patients with seizures/psychosis. All patients had poor immune status due to nutritional and metabolic causes. Neurological presentations included focal encephalitis, multifocal encephalitis and diffuse meningoencephalitis. The three groups had distinct symptoms and imaging features, with some overlap. Magnetic resonance imaging showed single or multiple nodular or ring-enhancing lesions often at the grey-white junction with subcortical white matter perifocal oedema. Within the large diffuse lesions there were discrete small haemorrhagic lesions and contrast medium administration showed fine-beaded parallel lines or small discrete nodules traversing the white matter suggesting perivenous spread. Complete clinical recovery was noted in 12 patients after several 6-week courses of pyrimethamine and sulfonamide/clindamycin. Five patients required two such courses, three patients required three courses, three patients required five courses and two patients required six courses for the final radiological healing, which was complete in nine patients. One patient was lost to follow-up and one patient died of cardiomyopathy. Knowledge of these three distinct initial presentations may help in the early diagnosis of cranial toxoplasmosis in HIV-seronegative patients. Prognosis in early cases is generally good but complete recovery may need several courses of treatment.

Comparison of PCR-enzyme-linked immunosorbent assay and real-time PCR assay for diagnosis of an unusual case of cerebral toxoplasmosis in a stem cell transplant recipient.

A PCR-enzyme-linked immunosorbent assay and a real-time PCR assay were compared for diagnosis and follow-up of cerebral toxoplasmosis in a stem cell transplant recipient. The sensitivity of detection was similar for both assays but was higher when the assays were performed on buffy coat rather than on whole blood or serum.