Multicenter evaluation of the Toxoplasma gondii Real-TM (Sacace) kit performance for the molecular diagnosis of toxoplasmosis.

The molecular detection of Toxoplasma gondii DNA is a key tool for the diagnosis of disseminated and congenital toxoplasmosis. This multicentric study from the Molecular Biology Pole of the French National Reference Center for toxoplasmosis aimed to evaluate Toxoplasma gondii Real-TM PCR kit (Sacace). The study compared the analytical and clinical performances of this PCR assay with the reference PCRs used in proficient laboratories. PCR efficiencies varied from 90% to 112%; linearity zone extended over four log units (R2 > 0.99) and limit of detection varied from 0.01 to ≤1 Tg/mL depending on the center. Determined on 173 cryopreserved DNAs from a large range of clinical specimens, clinical sensitivity was 100% [106/106; 95 confidence interval (CI): 96.5%-100%] and specificity was 100% (67/67; 95 CI: 94.6%-100%). The study revealed two potential limitations of the Sacace PCR assay: the first was the inconsistency of the internal control (IC) when added to the PCR mixture. This point was not found under routine conditions when the IC was added during the extraction step. The second is a lack of practicality, as the mixture is distributed over several vials, requiring numerous pipetting operations. Overall, this study provides useful information for the molecular diagnosis of toxoplasmosis; the analytical and clinical performances of the Sacace PCR kit were satisfactory, the kit having sensitivity and specificity similar to those of expert center methods and being able to detect low parasite loads, at levels where multiplicative analysis gives inconsistently positive results. Finally, the study recommends multiplicative analysis in particular for amniotic fluids, aqueous humor, and other single specimens.

A Trichinella britovi outbreak in the Northern Alps of France: investigation by a local survey network.

We describe a small family outbreak of trichinellosis caused by the consumption of raw ham from a wild boar (Sus scrofa) hunted in the northern Alps of France in February 2022. Out of the six people, aged 3-69 years, who consumed the meat, three were confirmed cases, and three were suspected cases. Eosinophilia detected in four people was the hallmark that drove the diagnosis. Three patients presented with myalgia, two with intense and prolonged chest pain, and one with elevated troponin. One patient presented with dermographism during treatment. Anti-Trichinella IgG were detected in three symptomatic individuals after about ten weeks. One patient had negative serology and no symptoms, but was on long-term corticosteroid therapy. Trichinella britovi larvae (8.3 larvae/g) were detected in the wild boar meat remnants. Trichinellosis is rare in France, but this family outbreak is reminiscent of the circulation of this pathogen in wild animals, highlighting the need to inform hunters about the risk of infection linked to the consumption of raw meat of game animals, and about the need for veterinary inspection of game meat. The consumption of raw meat outside controlled circuits is a practice not devoid of risks, which justifies raising the awareness of hunters, doctors, and medical biologists.

Title: Un foyer de Trichinella britovi dans les Alpes du Nord françaises : investigation par un réseau local de prospection. Abstract: Nous décrivons une épidémie familiale de trichinellose causée par la consommation de jambon cru d'un sanglier (Sus scrofa) chassé dans le nord des Alpes françaises en février 2022. Sur les six personnes âgées de 3 à 69 ans qui ont consommé la viande, trois étaient des cas confirmés, et trois étaient des cas suspects. L'éosinophilie détectée chez quatre personnes a permis d'évoquer le diagnostic. Trois patients présentaient des myalgies, et deux des douleurs thoraciques intenses et prolongées dont un avec une troponine élevée. Un patient a présenté un dermographisme pendant le traitement. Des IgG anti-Trichinella ont été détectées chez trois individus symptomatiques après environ dix semaines. Un des patients avait une sérologie négative et aucun symptôme mais était sous corticothérapie au long cours. Des larves de Trichinella britovi (8,3 larves/g) ont été détectées dans les restes du jambon de sanglier incriminé. La trichinellose est rare en France, mais cette épidémie familiale rappelle la circulation de cet agent pathogène chez les animaux sauvages, qui nécessite d'informer les chasseurs sur les risques d'infections liés à la consommation de viande crue de gibier, et de préconiser un contrôle vétérinaire des viandes de gibier. La consommation de viande crue en dehors des circuits contrôlés est une pratique non dénuée de risques, qui justifie une sensibilisation des chasseurs, médecins et biologistes médicaux.

Correction: A systematic review and an individual patient data meta-analysis of ivermectin use in children weighing less than fifteen kilograms: Is it time to reconsider the current contraindication?

[This corrects the article DOI: 10.1371/journal.pntd.0009144.].

Serological diagnosis of toxoplasmosis: evaluation of the commercial test recomLine Toxoplasma IgG immunoblot (Mikrogen) based on recombinant antigens.

BACKGROUND: IgG detection to determine immune status to Toxoplasma gondii infection and seroconversion mainly relies on ELISA techniques and, if necessary, on a confirmatory test, Western blot. This study evaluated the performance of the recomLine Toxoplasma IgG immunoblot (IB-recomLine) (Mikrogen) as a confirmatory test on a large number of sera. A total of 171 sera were selected (113 patients) and had previously been analyzed by two ELISA tests, ARCHITECT (Abbott) and VIDAS (bioMérieux) ± LDBIO-Toxo II IgG Western blot (WB-LDBIO) (LDBio). The sera were classified into three groups: group 1 included 50 sera without difficulty in interpreting the IgG results (patients with documented past infection or uninfected); group 2 included 47 sera with difficulty in interpreting the ELISA results; and group 3 included 74 sequential sera from 25 pregnant women with seroconversion. RESULTS: In group 1, overall IgG agreements were 94% and 90% with ARCHITECT and VIDAS, respectively. In group 2, low agreement was observed between IB-recomLine and WB-LDBIO, with eight false-positive and 13 false-negative results. In group 3, 4/13 seroconversions were detected earlier with IB-recomLine compared to other tests. CONCLUSIONS: IB-recomLine allowed for earlier diagnosis of toxoplasmic seroconversion compared to both ELISA tests and WB-LDBIO but led to insufficient performance to confirm the immune status when ELISA results were discordant or equivocal.

Title: Diagnostic sérologique de la toxoplasmose : évaluation du test commercial recomLine Toxoplasma IgG immunoblot (Mikrogen) basé sur des antigènes recombinants. Abstract: Contexte : La détection des IgG pour déterminer le statut immunitaire vis-à-vis de l'infection à Toxoplasma gondii et de la séroconversion repose principalement sur les techniques ELISA et, si nécessaire, sur un test de confirmation, le Western blot. Cette étude a évalué les performances de l'immunoblot recomLine Toxoplasma IgG (IB-recomLine) (Mikrogen) en tant que test de confirmation sur un grand nombre de sérums. Un total de 171 sérums ont été sélectionnés (113 patients) et ont été préalablement analysés par deux tests ELISA, ARCHITECT (Abbott) et VIDAS (bioMérieux) ± LDBIO-Toxo II IgG Western blot (WB-LDBIO) (LDBio). Les sérums ont été classés en trois groupes : le groupe 1 comprenait 50 sérums sans difficulté d'interprétation des résultats IgG (patients avec antécédents d'infection documentée ou non infectés); le groupe 2 comprenait 47 sérums avec des difficultés d'interprétation des résultats ELISA; le groupe 3 comprenait 74 sérums séquentiels de 25 femmes enceintes séroconverties. Résultats : Dans le groupe 1, les concordances globales des IgG étaient respectivement de 94 % et 90 % avec ARCHITECT et VIDAS. Dans le groupe 2, une faible concordance a été observée entre IB-recomLine et WB-LDBIO, avec huit faux positifs et 13 faux négatifs. Dans le groupe 3, 4/13 séroconversions ont été détectées plus tôt avec IB-recomLine par rapport aux autres tests. Conclusions : IB-recomLine a permis un diagnostic plus précoce de la séroconversion toxoplasmique par rapport aux tests ELISA et WB-LDBIO, mais a conduit à des performances insuffisantes pour confirmer le statut immunitaire lorsque les résultats ELISA étaient discordants ou équivoques.

Toxoplasmosis in patients with an autoimmune disease and immunosuppressive agents: A multicenter study and literature review.

BACKGROUND: Cases of Toxoplasma reactivation or more severe primary infection have been reported in patients receiving immunosuppressive (IS) treatment for autoimmune diseases (AID). The purpose of this study was to describe features of toxoplasmosis occurring in patients with AID treated by IS therapy, excluded HIV-positive and transplant patients. METHODS: A multicenter descriptive study was conducted using data from the French National Reference Center for Toxoplasmosis (NRCT) that received DNA extracts or strains isolated from patients, associated with clinical data. Other cases were retrieved through a questionnaire sent to all French parasitology and internal medicine departments. Furthermore, a systematic literature review was conducted. RESULTS: 61 cases were collected: 25 retrieved by the NRCT and by a call for observations and 36 from a literature review. Half of the cases were attributed to reactivation (50.9%), and most of cases (49.2%) were cerebral toxoplasmosis. The most common associated AID were rheumatoid arthritis (28%) and most frequent treatments were antimetabolites (44.3%). Corticosteroids were involved in 60.7% of cases. Patients had a favorable outcome (50.8%) but nine did not survive. For 12 cases, a successful Toxoplasma strain characterization suggested the possible role of this parasitic factor in ocular cases. CONCLUSION: Although this remains a rare condition, clinicians should be aware for the management of patients and for the choice of IS treatment.

Altiratinib blocks Toxoplasma gondii and Plasmodium falciparum development by selectively targeting a spliceosome kinase.

The Apicomplexa comprise a large phylum of single-celled, obligate intracellular protozoa that include Toxoplasma gondii, Plasmodium, and Cryptosporidium spp., which infect humans and animals and cause severe parasitic diseases. Available therapeutics against these diseases are limited by suboptimal efficacy and frequent side effects, as well as the emergence and spread of resistance. We use a drug repurposing strategy and identify altiratinib, a compound originally developed to treat glioblastoma, as a promising drug candidate with broad spectrum activity against apicomplexans. Altiratinib is parasiticidal and blocks the development of intracellular zoites in the nanomolar range and with a high selectivity index when used against T. gondii. We have identified TgPRP4K of T. gondii as the primary target of altiratinib using genetic target deconvolution, which highlighted key residues within the kinase catalytic site that conferred drug resistance when mutated. We have further elucidated the molecular basis of the inhibitory mechanism and species selectivity of altiratinib for TgPRP4K and for its Plasmodium falciparum counterpart, PfCLK3. Our data identified structural features critical for binding of the other PfCLK3 inhibitor, TCMDC-135051. Consistent with the splicing control activity of this kinase family, we have shown that altiratinib can cause global disruption of splicing, primarily through intron retention in both T. gondii and P. falciparum. Thus, our data establish parasitic PRP4K/CLK3 as a potential pan-apicomplexan target whose repertoire of inhibitors can be expanded by the addition of altiratinib.

Diagnostic Accuracy of LDBIO-Toxo II IgG and IgM Western Blot in Suspected Seroconversion in Pregnancy: A Multicentre Study.

The high sensitivity of the automated tests used for Toxoplasma gondii serology can yield false-positive IgM results due to aspecific reactions. On the other hand, specific therapy can delay IgG production and, therefore, the diagnosis of seroconversion. There is a need for confirmation tests to early detect seroconversions during pregnancy. We conducted a multicentre study to evaluate the diagnostic accuracy of the Toxo II IgG and a new, not yet commercialised Toxo II IgM western blot (WB) (LDBio diagnostics Lyon France) on 229 sera corresponding to 93 patients with seroconversions and 158 sera corresponding to 68 patients with nonspecific IgM. Sensitivity was 97.8% for IgM WB and 98.9% for IgG WB. Specificity was 89.7% and 100%, respectively. The concordance between IgM and IgG Toxo WB with the final diagnosis was very good, K = 0.89 and K = 0.99, respectively. In 5 cases (5.4%), the appearance of IgM, and in 55 cases (59.1%), the appearance of IgG was recorded by WB earlier than by traditional tests. In 10 cases (10.8%), IgM was detected after the traditional tests and in 2 cases (2.2%) for IgG. The association of IgG and IgM WB on the same sample not only detected all seroconversions but also correctly identified most of the false-positive results.

Molecular Diagnosis of Toxoplasmosis: Multicenter Evaluation of the Toxoplasma RealCycler Universal PCR Assay on 168 Characterized Human Samples.

Real-time PCR plays a crucial role in the diagnosis of toxoplasmosis. In this multicenter study, the Toxoplasma RealCycler Universal assay was assessed for the diagnosis of toxoplasmosis by eight reference laboratories. DNAs from diverse clinical samples were included: 141 characterized samples from patients with different clinical forms of proven toxoplasmosis and 27 from patients without toxoplasmosis were tested in duplicate with the commercial assay. Final diagnosis was affirmed by each center by analysis of clinical settings and biological follow-up. Calibrated Toxoplasma gondii standards and 11 external quality control samples were also included. Discrepant results observed after the first run of commercial PCR were controlled by both reference and commercial PCR assays. Using the commercial assay, the detection threshold varied from 0.01 to 1 tachyzoites/mL, depending on the center. The relationship between crossing point and DNA concentration was linear over 4 log units (r2 > 0.99), and PCR efficiencies were satisfactory (89% to 104%). The results of the 11 external quality control samples were concordant after one retesting, but those for 3 clinical samples remained discrepant. Sensitivity and specificity were calculated at 97.8% (95% CI, 97.8%-100%) and 100% (95% CI, 87.2%-100%), respectively. Provided that PCRs are performed at least in duplicate to detect low parasitic loads, Toxoplasma RealCycler Universal PCR showed suitable performances to diagnose the different forms of toxoplasmosis.

Molecular diagnosis of toxoplasmosis: recent advances and a look to the future.

INTRODUCTION: Toxoplasmosis is a globally distributed parasitic infection that can be particularly severe when opportunistic or congenital. Its diagnosis requires accurate and rapid techniques that rely mainly on serology and molecular methods. AREAS COVERED: The aim of this review was to discuss the positioning of the molecular diagnosis of toxoplasmosis according to the different clinical situations possibly resulting from infection with T. gondii, and to detail recent developments in this technique. The English and French literature were searched with the following keywords: 'Toxoplasmosis', "Molecular diagnosis" and 'PCR'. EXPERT OPINION: Molecular techniques have revolutionized the diagnosis of toxoplasmosis, and practices have considerably evolved over the past decades. However, there is still a high degree of inter-laboratory heterogeneity which impairs comparisons between results and studies. Efforts to standardize practices are underway.

Multicenter Comparative Assessment of the TIB MolBiol Toxoplasma gondii Detection Kit and Four Laboratory-Developed PCR Assays for Molecular Diagnosis of Toxoplasmosis.

Toxoplasmosis can be a life-threatening infection, particularly during pregnancy and in immunocompromised patients. The biological diagnosis of toxoplasmosis is challenging and has been revolutionized by molecular detection methods. This article summarizes the data of a multicenter study involving four centers to assess the performances of a commercial PCR assay as compared with four in-house PCR assays using Toxoplasma gondii standards, 20 external quality control specimens, and 133 clinical samples. This clinical cohort includes well-characterized clinical samples corresponding to different clinical situations: confirmed congenital toxoplasmosis (44 samples), toxoplasmosis in immunocompromised patients (25 samples), and chorioretinitis (5 samples). Furthermore, 59 samples from patients without toxoplasmosis were included as negative controls. The analytical sensitivities of the five methods tested were very similar; and the limit of Toxoplasma DNA detection was around 0.01 T. gondii genome per reaction for all the methods. The overall concordance between the commercial PCR and the four in-house PCR assays was 97.7% (130/133). The clinical sensitivity and specificity were >98% and could be increased for the commercial kit when PCR was performed in multiplicate to detect low parasitic loads. In conclusion, the commercial PCR assay shows suitable performances to diagnose the different clinical forms of toxoplasmosis.

A systematic review and an individual patient data meta-analysis of ivermectin use in children weighing less than fifteen kilograms: Is it time to reconsider the current contraindication?

BACKGROUND: Oral ivermectin is a safe broad spectrum anthelminthic used for treating several neglected tropical diseases (NTDs). Currently, ivermectin use is contraindicated in children weighing less than 15 kg, restricting access to this drug for the treatment of NTDs. Here we provide an updated systematic review of the literature and we conducted an individual-level patient data (IPD) meta-analysis describing the safety of ivermectin in children weighing less than 15 kg. METHODOLOGY/PRINCIPAL FINDINGS: A systematic review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) for IPD guidelines by searching MEDLINE via PubMed, Web of Science, Ovid Embase, LILACS, Cochrane Database of Systematic Reviews, TOXLINE for all clinical trials, case series, case reports, and database entries for reports on the use of ivermectin in children weighing less than 15 kg that were published between 1 January 1980 to 25 October 2019. The protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO): CRD42017056515. A total of 3,730 publications were identified, 97 were selected for potential inclusion, but only 17 sources describing 15 studies met the minimum criteria which consisted of known weights of children less than 15 kg linked to possible adverse events, and provided comprehensive IPD. A total of 1,088 children weighing less than 15 kg were administered oral ivermectin for one of the following indications: scabies, mass drug administration for scabies control, crusted scabies, cutaneous larva migrans, myiasis, pthiriasis, strongyloidiasis, trichuriasis, and parasitic disease of unknown origin. Overall a total of 1.4% (15/1,088) of children experienced 18 adverse events all of which were mild and self-limiting. No serious adverse events were reported. CONCLUSIONS/SIGNIFICANCE: Existing limited data suggest that oral ivermectin in children weighing less than 15 kilograms is safe. Data from well-designed clinical trials are needed to provide further assurance.

A brain cyst load-associated antigen is a Toxoplasma gondii biomarker for serodetection of persistent parasites and chronic infection.

BACKGROUND: Biomarker discovery remains a major challenge for predictive medicine, in particular, in the context of chronic diseases. This is true for the widespread protozoan Toxoplasma gondii which establishes long-lasting parasitism in metazoans, humans included. This microbe successively unfolds distinct genetic programs that direct the transition from high to low replicative potential inside host cells. As a slow-replicating cell, the T. gondii bradyzoite developmental stage persists enclosed in a cyst compartment within tissues including the nervous system, being held by a sustained immune equilibrium which accounts for the prolonged clinically silent phase of parasitism. Serological surveys indicate that nearly one third of the human population has been exposed to T. gondii and possibly host bradyzoites. Because any disruption of the immune balance drives the reverse transition from bradyzoite to fast replicating tachyzoite and uncontrolled growth of the latter, these people are at risk for life-threatening disease. While serological tests for discriminating recent from past infection are available, there is yet no immunogenic biomarker used in the serological test to allow ascertaining the presence of persistent bradyzoites. RESULTS: Capitalizing on genetically engineered parasites induced to produce mature bradyzoites in vitro, we have identified the BCLA/MAG2 protein being restricted to the bradyzoite and the cyst envelope. Using laboratory mice as relevant T. gondii host models, we demonstrated that BCLA/MAG2 drives the generation of antibodies that recognize bradyzoite and the enveloping cyst structure. We have designed an ELISA assay based on a bacterially produced BCLA recombinant polypeptide, which was validated using a large collection of sera from mice of different genetic backgrounds and infected with bcla+ or bcla-null cystogenic and non-cystogenic T. gondii strains. To refine the design of the ELISA assay, we applied high-resolution BCLA epitope mapping and identified a specific combination of peptides and accordingly set up a selective and sensitive ELISA assay which allowed the detection of anti-BCLA/MAG2 antibodies in the sera of human patients with various forms of toxoplasmosis. CONCLUSIONS: We brought proof of principle that anti-BCLA/MAG2 antibodies serve as specific and sensitive serological markers in the perspective of a combinatorial strategy for detection of persistent T. gondii parasitism.

Impact of pre-analytic step duration on molecular diagnosis of toxoplasmosis for five types of biological samples.

INTRODUCTION: Toxoplasma-PCR is essential to diagnose ocular, cerebral, disseminated and congenital toxoplasmosis. This multicenter study evaluated the impact of sample storage duration at +4°C on PCR assay performances in order to propose guidelines for the storage of samples during shipment or/and before PCR. MATERIALS AND METHODS: Five matrices, amniotic (AF), cerebrospinal (CSF), and bronchoalveolar lavage fluids (BALF), whole blood (WB) and buffy coat (BC), were artificially spiked with different amounts of Toxoplasma gondii (20, 100, 500 tachyzoites per mL of sample) or with previously infected THP1 cells. DNA extractions were performed at day 0 and after 2, 4 and 7 days of storage at +4°C. Each extract was amplified at least twice by real-time PCR. RESULTS: A total of 252 spiked samples was studied. No increase of crossing point was observed and all samples were positive for AF, BALF, BC and infected THP1-spiked WB after up to 7 days at 4°C. For CSF spiked with 20 parasites/mL, only 50% of PCR reactions were positive at D7 (p<0.05). For WB spiked with type II parasites, all reactions remained positive at D7 but amplifications were significantly delayed from D2; and for WB spiked with RH strain, the proportion of positive reactions decreased at D7. CONCLUSION: The storage of clinical samples at +4°C is compatible with the molecular detection of T. gondii parasites. Provided that PCR assays are performed in duplicate, storage of samples is possible up to 7 days. However, from the fifth day onwards, and for samples susceptible to contain low parasitic loads, we recommend to perform the PCR in multiplicate.

Serology for Toxoplasma in Immunocompromised Patients: Still Useful?

Toxoplasmosis represents one of the most common comorbidity factors in solid organ or hematopoietic stem cell transplant recipients as well as in other immunocompromised patients. In the past decades, availability and performance of molecular tools for the diagnosis or the exclusion of toxoplasmosis in these patients have greatly improved. However, if accurately used, serology remains a complementary and essential diagnostic tool for physicians and medical parasitologists for the prevention and management of toxoplasmosis in immunocompromised patients as well. It is required for determination of the immunological status of patients against Toxoplasma. It also helps diagnose and monitor complex cases of opportunistic Toxoplasma infection in immunocompromised patients. New perspectives are available to further enhance their yield and ease of use.

Target Identification of an Antimalarial Oxaborole Identifies AN13762 as an Alternative Chemotype for Targeting CPSF3 in Apicomplexan Parasites.

Boron-containing compounds represent a promising class of molecules with proven efficacy against a wide range of pathogens, including apicomplexan parasites. Following lead optimization, the benzoxaborole AN13762 was identified as a preclinical candidate against the human malaria parasite, yet the molecular target remained uncertain. Here, we uncovered the parasiticidal mechanisms of AN13762, by combining forward genetics with transcriptome sequencing and computational mutation discovery and using Toxoplasma gondii as a relevant model for Apicomplexa. AN13762 was shown to target TgCPSF3, the catalytic subunit of the pre-mRNA cleavage and polyadenylation complex, as the anti-pan-apicomplexan benzoxaborole compound, AN3661. However, unique mutations within the TgCPSF3 catalytic site conferring resistance to AN13762 do not confer cross-protection against AN3661, suggesting a divergent resistance mechanism. Finally, in agreement with the high sequence conservation of CPSF3 between Toxoplasma and Cryptosporidium, AN13762 shows oral efficacy in cryptosporidiosis mouse model, a disease for which new drug development is of high priority.

Prospective study of serum and aqueous humour anti-Hsp70.1 IgG antibody levels in ocular toxoplasmosis.

AIMS: We evaluate whether the serum and aqueous humour (AH) level of IgG anti-Hsp70.1 antibodies improved the biological diagnosis of ocular toxoplasmosis. METHODS AND RESULTS: In this prospective cross-sectional and multicentre study, serum and AH were collected at the time of active uveitis. Anti-Hsp70.1-antibody levels were determined by ELISA. Patients with confirmed (Group A1, n = 21) or suspected ocular toxoplasmosis (group A2, n = 30) were enrolled, as well as a control group of patients with cataract (group B, n = 42). Serum IgG anti-Hsp70.1 antibody levels were not significantly different within the group of uveitis patients (A1, n = 21 vs A2, n = 30, P = .8) and were significantly associated with the affected retinal zone (P = .006) and with the size of the retinal lesion (P = .03). Serum anti-Hsp70.1 antibody level was positive in 10 out of the 18 patients of group A2. Significant anti-Hsp-70.1 antibody level in AH was reported in only three patients (3 eyes) with confirmed ocular toxoplasmosis. CONCLUSION: While the level of IgG anti-Hsp-70.1 antibody in AH did not improve the laboratory diagnosis of ocular toxoplasmosis, its level in serum was of major significance for retinal damage diagnosis.

Chronic toxoplasmosis and sleepiness in obstructive sleep apnea: Is there a link?

INTRODUCTION: Sleepiness is the main clinical expression of obstructive sleep apnea (OSA) syndrome resulting from upper airway collapse. Recent studies have discussed the fact that the presence of T. gondii cysts in the brain and the resulting biochemical and immunological mechanisms could be linked to neurobehavioral disorders. The aim of the present study was to explore the potential impact of chronic toxoplasmosis on sleepiness and on obstructive sleep apnea (OSA) severity in OSA obese patients. MATERIALS AND METHODS: A case control study on obese patients screened for OSA was performed. According to the sleep disorder and matched based on gender, age and body mass index (BMI), two groups of obese patients were selected from our sample collection database. All patients were tested for toxoplasmosis serological status measuring anti-Toxoplasma IgG and IgM levels. Univariable and multivariable logistic regression models were performed to assess the impact of chronic toxoplasmosis on sleepiness and OSA severity. RESULTS: 107 obese patients suffering from OSA were included in the study (median age: 53.3 years Interquartile range (IQR): [41.9-59.9]; median BMI: 39.4 kg/m2 IQR: [35.5-44.1], apnea-hypopnea index = 27.5 events/h [10.7-49.9]). Chronic toxoplasmosis was present in 63.4% and 70.7% of patients with or without sleepiness (p = 0.48), respectively and was not associated either to sleepiness (OR: 0.76, 95% CI: [0.52; 2.33], p = 0.64) or OSA severity (OR = 1.75, 95% CI: [0.51; 5.98] p = 0.37). CONCLUSION: Although chronic Toxoplasma infection in immunocompetent humans has been associated to several behavioral disorders or pathologies in recent literature, we demonstrate here that chronic toxoplasmosis is not associated to sleepiness and to sleep apnea syndrome severity in obese patients suspected of sleep apnea syndrome.

Performance of a Toxo IgM prototype assay for the diagnosis of maternal and congenital Toxoplasma infections.

Background Testing for anti-Toxoplasma immunoglobulin (Ig)M is of main importance in the context of pregnancy to promptly alert to an acute maternal infection prior to the detection of IgG and to identify infected newborns. Their absence helps exclude a recent maternal infection in the presence of IgG. Methods The performance of a Toxo IgM immunocapture prototype assay (bioMérieux, France) was compared with that of the VIDAS® Toxo IgM and the ARCHITECT® Toxo IgM (Abbott, Germany) assays at Grenoble and Lyon (France). A total of 1446 sera were sampled from (i) 1054 pregnant women found by routine workup to have no infection (n = 843), an acute infection (<4 months) (n = 28) or a chronic infection (>4 months) with residual (n = 120) or no IgM (n = 62); (ii) 50 three-serum panels sampled immediately after a maternal seroconversion; (iii) 242 samples taken in 41 children with a congenital toxoplasmosis (n = 122) and in 40 uninfected children (n = 120). Results In pregnant women, the overall agreement with the VIDAS® assay was 99.23% (CI: 99.16-99.27) and that with the ARCHITECT® assay was 99.14% (CI: 99.07-99.17). Sensitivity of the Toxo IgM prototype assay was 100% (CI: 87.66-100.00) and specificity was 99.64% (98.96-99.93). In acute maternal infections, IgM assays were detected as early with the prototype as with the other two. In the congenitally infected children, IgM were detected on their first sample in 25/40 with the prototype vs. 23/40 with the VIDAS® test. No uninfected child had positive IgM. Conclusion The prototype performed comparably to the ARCHITECT® and VIDAS® Toxo IgM assays for the diagnosis of maternal and congenital toxoplasmosis.

How to estimate time of infection with Toxoplasma gondii in pregnant women. Use of specific IgG and IgM kinetics by 7 techniques on 691 sera.

A difficulty when detecting both anti-Toxoplasma gondii-specific IgG and IgM in pregnant women is estimating the date of infection. The aim of this study was to compare the anti-Toxoplasma-specific immunoglobulin kinetics of 7 serological techniques to date the infection and to draw kinetic curves that are easy to use on a daily basis. IgG and IgM antibodies were measured on 691 sera samples. IgM appeared a few days, less than 1 week, after the beginning of the infection. Then, the levels of IgM reached a peak at approximately 3, 4, and 5 weeks with Toxo-ISAGA® IgM, IgM homemade indirect immunofluorescence assays, and Vidas Toxo® IgM, respectively. Furthermore, the Architect Toxo® IgG titers were higher than those of the Vidas Toxo® IgG results in recent infection (less than 6 months). This study provides new average IgM and IgG curves that can help to determine the approximate date of infection.