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.

Characteristic and clinical relevance of Candida mannan test in the diagnosis of probable invasive candidiasis.

The gold standard laboratory tests used to diagnose invasive Candida infection (ICI) are based on the in vitro culture of blood or samples from other sterile sites. However, these tests have limited sensitivity (Se) and are generally not diagnostic until late in the infectious process. The Serion Candida mannan kit was evaluated for the diagnosis of ICI at Grenoble University Hospital (France) between 2007 and 2011. The results were then compared with worldwide data published between 1997 and 2011. This retrospective study was based on follow-up from the investigation of 162 patients of whom 91 had proven ICI; 13 had Candida colonization index (CCI) scores ≥0.42, positive mannan tests, with nonconcomitant infections; and 58 had no evidence of Candida infection. Candida albicans, C. glabrata, C. tropicalis, and C. parapsilosis were the etiologic agents in 104 patients. For patients with or without ICI, the 12-week mortality rates were 35/104 (33.7%) and 6/58 (10.3%), respectively. The mannan diagnostic specificity was 51% and Se was 77%. However, in the meta-analysis (n = 1,536), values were 86% and 62%, respectively. Positive mannan test results may appear early (median 6 days) in the development of candidemia and have moderate diagnostic value for ICI, with a negative predictive value of 83%. In patients at risk of ICI with negative candidemia, the combination of Candida mannan test data with a CCI score ≥0.42 may improve the diagnosis of probable ICI.

Minimum inhibitory concentrations of amphotericin B against Candida krusei isolates from a French teaching hospital laboratory: a retrospective study over 8 years.

Recent studies have shown decreased susceptibility of Candida krusei to amphotericin B (AmB), in addition to its inherent resistance to fluconazole. The susceptibility of C. krusei to AmB was studied in the Parasitology-Mycology laboratory of Grenoble Teaching Hospital, France. Between 2003 and 2011, we analysed 200 C. krusei isolates from 130 patients. The isolates were mainly collected in intensive care, cardio-thoracic and cancer/haematology units. Minimum inhibitory concentrations (MICs) were determined by the E-test method. The modal MIC was 0.5 µg ml(-1); the MIC(50) and MIC(90) (MICs encompassing 50% and 90% of all isolates tested, respectively) were 0.5 µg ml(-1) and 1 µg ml(-1). The Cuzick's and Kendall's tests showed a significant increase in MIC values between 2003 and 2011 (P = 0.001 and P ≤ 0.001, respectively), regardless of age or gender. No statistical difference was reached with these tests when the first 100 or 50 data were excluded. Despite the increase observed in the first period of the study, our results confirm the low AmB MICs reported in previous studies. However, some authors have recently reported much higher MICs. This discrepancy cannot be explained by method biases and could reflect C. krusei epidemiological differences among populations.

Characteristics and clinical relevance of the quantitative touch-down major surface glycoprotein polymerase chain reaction in the diagnosis of Pneumocystis pneumonia.

The evaluation of quantitative polymerase chain reaction (PCR) characteristics can increase the accuracy of the laboratory diagnosis of Pneumocystis pneumonia (PCP). Between July 2008 and September 2009, 66 non-sequential prospective bronchoalveolar lavage (BAL) samples, obtained from five HIV-infected and 49 non HIV-infected patients were investigated, using a quantitative-touch-down-PCR to determine the number of copies of major surface glycoprotein (MSG) genes of Pneumocystis jirovecii (q-TD-MSG-PCR). PCP was confirmed by microscopic observation of Pneumocystis, radio-clinical and therapeutic data in 18/54 patients. For PCP, the cut-off was 54.3 MSG copies per ml of BAL fluid. The PCR was positive in these same 18 cases and it was the only positive assay in two cases and the earliest diagnosis test in one case of PCP relapse. The likelihood positive ratio, sensitivity and specificity of the q-TD-MSG-PCR were 44, 100% and 97.7%, respectively. The Predictive Negative Value was 100% and the Predictive Positive Value of 95.5%, the intra- and inter-assay variability values were 2.7% (at more than 30 MSG copies) and 11.7% (at 10,000 MSG copies), respectively. Quantitative PCR can help diagnose PCP even in cases of low Pneumocystis load and might decrease morbidity in association with very early specific treatments.

Severe Pneumocystis jirovecii pneumonia in an idiopathic CD4+ lymphocytopenia patient: case report and review of the literature.

INTRODUCTION: When diagnosing Pneumocystis jirovecii pneumonia (PJP), the clinical suspicion must be confirmed by laboratory tests. PJP is rarely described in patients with idiopathic CD4+ lymphocytopenia (ICL), a rare T-cell deficiency of unknown origin with persistently low levels of CD4+ T-cells (<300 µl-1 or <20 % of total lymphocytes) but repeated negative human immunodeficiency virus (HIV) tests. We retrospectively analysed a case of an ICL patient with severe PJP associated with multiple opportunistic infections (OIs). We also reviewed the literature since 1986. CASE PRESENTATION: A laboratory-confirmed case of PJP associated with invasive candidiasis and cytomegalovirus infection was reported in an ICL patient. Despite early treatment, the patient died of respiratory failure under polymicrobial pneumonia. According to the literature, the mortality rate of ICL patients is 10.4 % (33/316). In ICL patients, the risk of OI is 83.2 % (263/316), with viral infections being the most prevalent (58.2 %, 184/316), followed by fungal infections (52.2 %, 165/316) and mycobacterial infections (15.5 %, 49/316). Dysimmunity is reported in 15.5 % (49/316) of ICL patients. Among the fungal infections, cryptococcal infections are the most prevalent (24.1 %, 76/316), followed by candidiasis (15.5 %, 49/316) and PJP (7.9 %, 25/316). CONCLUSIONS: The high risk of OIs underlines the importance of more vigorous preventative actions in hospitals. The response to therapy and the detection of early relapse of PJP may be monitored by several laboratory tests including quantitative PCR. It is essential to treat the ICL and to follow the guidelines concerning therapy and prophylaxis of OIs as given to HIV patients.

Contribution of anti-Hsp70.1 IgG antibody levels to the diagnostic certainty of clinically suspected ocular toxoplasmosis.

PURPOSE: Laboratory diagnosis of ocular toxoplasmosis, the major cause of posterior uveitis worldwide, can be improved. Heat shock protein (Hsp) 70 is involved in cellular infection by Toxoplasma gondii but also in the immune response to this parasite. The authors postulate that infected patients may exhibit serum IgG anti-Hsp70.1 antibodies and that determining the presence of these antibodies could improve the diagnosis of suspected ocular toxoplasmosis. METHODS: This retrospective case-control study included 26 laboratory-confirmed cases of ocular toxoplasmosis (group A), 41 clinically suspected cases (group B), and 67 currently healthy blood donors who were chronically infected with T. gondii (group C). Laboratory and clinical data were analyzed according to the ocular presentation and Goldmann-Witmer's coefficient. Serum and aqueous humor were sampled at the time of uveitis. Serum anti-Hsp70.1 antibody levels were obtained by ELISA. The probability of ocular toxoplasmosis was estimated by a logistic regression analysis that combined data from serum IgG anti-Hsp70.1 and aqueous-humor IgG anti-T. gondii antibody levels. RESULTS: Serum IgG anti-Hsp70.1 antibody levels were significantly increased in groups A and B when compared to the levels in control group C (P ≤ 0.0034). These levels correlated with the retinal lesion size (r = 0.301; P < 0.0349). Logistic probability and anti-Hsp70.1 antibodies in sera confirmed that 10 of 23 cases in group B were true ocular toxoplasmosis. CONCLUSIONS: Anti-Hsp70 may play a role in the immunopathogenesis of ocular Toxoplasma infection. This study showed that the anti-Hsp70.1 antibody and the logistic probability test can confirm clinically suspected ocular toxoplasmosis.