We compared three biological methods for the diagnosis of ocular toxoplasmosis (OT). Paired aqueous humor and serum samples from 34 patients with OT and from 76 patients with other ocular disorders were analyzed by three methods: immunoblotting or Western blotting (WB), the calculation of the GoldmannWitmer coefficient (GWC), and PCR. WB and GWC each revealed the intraocular production of specific anti-Toxoplasma immunoglobulin G in 81% of samples (30 of 37). PCR detected toxoplasmic DNA in 38% of samples (13 of 34). Nine of the 13 PCR-positive patients were immunocompetent. Combining the techniques significantly improved the diagnostic sensitivity, to 92% for the GWC-WB combination, 90% for the WB-PCR combination, and 93% for the GWC-PCR combination. The combination of all three techniques improved the sensitivity to 97%.Ocular toxoplasmosis (OT) is the main cause of posterior uveitis worldwide and is a frequent cause of vision loss (14,15,21). The current gold standard for the diagnosis of OT is ophthalmologic examination, but the findings may be equivocal for patients with atypical lesions. In particular, toxoplasmic retinochoroiditis can mimic acute retinal necrosis syndrome (1). Therefore, laboratory methods often are necessary to confirm the diagnosis of OT. The most reliable sample type is that of aqueous humor, which can be tested for local specific antibody (Ab) production or for Toxoplasma gondii DNA by PCR.Local Ab production can be detected with an immunoblotting method and quantified by calculating the GoldmannWitmer coefficient (GWC) (3). In both cases, the specific Ab profiles of serum and aqueous humor samples are compared. Specific Abs can be detected by enzyme-linked immunosorbent assay (ELISA) and/or by immunofluorescence (IF) assay.The aim of this study was to compare the sensitivities and specificities of these three biological methods for the diagnosis of OT. The design of this study is that of a prospective case series. MATERIALS AND METHODS Patients and methods.We analyzed data from a series of 110 patients diagnosed with various ocular disorders during a 15-month period (December 2004 to February 2006 at the Department of Ophthalmology, Pitié-Salpêtrière Hospital, Paris, France. In most cases, the clinical findings were suggestive of atypical Toxoplasma gondii retinochoroiditis but were inconclusive. In order to confirm the diagnosis, anterior-chamber paracentesis was performed, and aqueous humor was sampled (vitreous humor for 18 patients). Blood was sampled simultaneously. Some patients were tested two or three times during the study, yielding a total of 120 samples. Clinical findings suggestive of T. gondii retinochoroiditis (i.e., focal retinal necrosis and choroidal edema with possible old scars) associated with successful outcomes of specific treatments were considered the gold standard. Considering these findings, a final diagnosis of OT was made for 34 patients (39 samples). The controls consisted of nontoxoplasmic ocular infection (see Table S1 in the supplemental material) and...

T oxoplasmosis is a widespread parasitic infection that is frequently asymptomatic in immunocompetent patients. However, this obligate intracellular protozoan parasite can evade the immune system (1, 2) and persist for the life of its host in cyst form, predominantly in the brain, retina, and muscles. Reactivation of latent cysts may occur when the immune system fails to maintain cytokine pressure, which mainly relies on gamma interferon (IFN-␥) (3). Cyst reactivation can lead to ocular toxoplasmosis, cerebral toxoplasmosis (CT), or disseminated toxoplasmosis, which involves most frequently the lungs but potentially all organs. Failure of an efficient Th1 immune response mainly results from acquired immunosuppression, through HIV infection or immunosuppressive therapy. Both primary acquired and reactivated infections are life-threatening in immunocompromised patients (ICPs). Definitive diagnosis can be obtained by the detection of parasites in blood, cerebrospinal fluid (CSF), bronchoalveolar lavage (BAL) fluid, or virtually any tissue by using PCR, which is the most sensitive method (4).Prevention of CT in patients with HIV is an object of consensus, and guidelines recommend co-trimoxazole (sulfamethoxazole-trimethoprim) chemoprophylaxis in Toxoplasma-seropositive patients when CD4 ϩ cell counts fall below 200 cells/l (4), a prophylactic regimen which also protects patients from Pneumocystis jirovecii pneumonia. Nevertheless, toxoplasmosis remains Citation Robert-Gangneux F, Sterkers Y, Yera H, Accoceberry I, Menotti J, Cassaing S, Brenier-Pinchart M-P, Hennequin C, Delhaes L, Bonhomme J, Villena I, Scherer E, Dalle F, Touafek F, Filisetti D, Varlet-Marie E, Pelloux H, Bastien P. 2015. Molecular diagnosis of toxoplasmosis in immunocompromised patients: a 3-year multicenter retrospective study.

We evaluated the usefulness of a serum Aspergillus PCR assay for the diagnosis and prognosis of invasive aspergillosis in a study involving 941 patients for a total of 5146 serum samples. Fifty-one patients had proven/probable aspergillosis. We compared galactomannan (GM), PCR and mycologic analysis of pulmonary samples in both neutropenic and nonneutropenic patients. PCR performed in serum yielded 66.7% sensitivity, 98.7% specificity, 75.6% positive predictive value and 98.0% negative predictive value, while the GM index yielded 78.4% sensitivity, 87.5% specificity, 27% positive predictive value and 98.6% negative predictive value. The inclusion of PCR in the European Organization for Research and Treatment of Cancer (EORTC) and the Mycosis Study Group (MSG) mycologic criteria permitted the reclassification of nine other cases from possible to probable aspergillosis and increased the sensitivity to 71.7%. Combining the GM index with serum PCR increased the detection rate of invasive aspergillosis with 88.2% sensitivity. PCR was systematically negative in 16 patients with noninvasive forms of aspergillosis (namely aspergilloma and chronic aspergillosis). Remaining PCR positive after a period of 14 to 20 days of treatment was related to poor outcome at 30 and 90 days. Our results also indicate that, unlike the determination of the GM index, the initial fungus load as determined by PCR was highly predictive of 90-day mortality, with the rate of the latter being 15.8% for patients with <150 copies/mL vs. 73.2% for patients at or above that cutoff (p <0.0001). Therefore, PCR appears to be a powerful and interesting tool for the identification of patients with invasive aspergillosis who might benefit from more intense care.