Mannan antigenemia in the diagnosis of invasive Candida infections.

Because it is often difficult to diagnose invasive Candida infections, a sensitive hemagglutination inhibition assay to detect the surface antigen, mannan, was developed. Mannan antigenemia was detected early in the course of infection in 4 of 14 patients with systemic candidiasis and 2 of 5 patients with invasive gastrointestinal candidiasis. Mannan was not detected in 48 patients with noninvasive Candida or other systemic mycotic infections or in 99% of 234 patients in other control groups. Mannan antibodies were almost universally present in both candidiasis and control groups. In four patients with systemic candidiasis, an early period of mannan antigenemia was followed by a rapid rise in mannan antibody titer. These findings suggest that antemortem diagnosis would be improved in one-third of cases of invasive Candida infection detected by the hemagglutination inhibition assay. A positive test for serum mannan would be an early and specific signal of invasive disease.     

Non-cultural methods for the diagnosis of invasive fungal disease

Invasive fungal diseases carry a high mortality risk which can be reduced by early treatment. Diagnosing invasive fungal diseases is challenging, because invasive methods for obtaining histological samples are frequently not feasible in thrombocytopenic immunocompromised patients, while fungal cultures have low sensitivity and a long turn-around time. Non-cultural methods are fundamental for a rapid diagnosis of invasive fungal diseases and they include assays based on the detection of fungal antigens (galactomannan, Aspergillus-lateral flow device, [1,3]-β-D-glucan, mannan), antibodies, such as anti-mannan, and molecular tests. With the exception of some molecular methods for rare fungi, the non-cultural assays are usually applied to the diagnosis of invasive aspergillosis, invasive candidiasis and pneumocystosis. The performance of a single test or a combination of tests will be discussed, with particular focus on choosing the most appropriate marker(s) for every specific patient population. Reasons for potential false-positive or false-negative results will be discussed.     

Serologic analysis of antigen-specific reactivity in patients with systemic candidiasis

Antibody responses to candidal polypeptides and mannans were studied in patients with systemic candidiasis, candiduria, and other fungal and bacterial infections, and in healthy laboratory personnel to determine the diagnostic value of these immunologic responses. When tested by immunoblot analysis, sera from 15 patients with systemic candidiasis frequently contained antibodies to three antigens: 15 of 15 sera from patients with invasive disease reacted to a molecular species having a molecular weight (Mr of 90-200 kd, 13 of 15 reacted with a 45-kd polypeptide, and 12 of 15 reacted with a 17-kd polypeptide. Lesser reactivity was observed in 11 of 15 sera with a 28-kd candidal antigen and in 9 of 15 to a 57-kd candidal antigen. Quantitation of antibody titers against the 45-kd candidal polypeptide demonstrated much higher immunoreactivity in patients with systemic candidiasis than in patients with superficial candidal infections, bacterial infections, other systemic mycoses, and healthy individuals. Antimannan antibody titers were measured by an enzyme-linked immunosorbent assay (ELISA) and these titers were also higher in patients with systemic candidiasis than in patients in the other categories. These differences, however, were less than those observed with the anti-45-kd polypeptide antibody. Therefore, the ability to detect systemic candidiasis is improved by testing sera for immunoreactivity to polypeptide and to mannan antigens from Candida albicans. Detection of polypeptide antibodies improves the serodiagnosis of systemic candidiasis.     

Clinical efficacy and safety of intravenous itraconazole in the management of invasive candidiasis in patients of surgery and critical care

Although itraconazole exhibits potent activity against Candida species, there have been few studies examining the use of intravenous itraconazole in the treatment of invasive candidiasis. A nationwide multicenter clinical study was conducted to evaluate the efficacy and safety of intravenous itraconazole in the management of invasive candidiasis, including non-albicans Candida species, in non-neutropenic patients undergoing surgery and critical care. Between September 2007 and August 2009, patients with proven and presumed candidiasis were enrolled at 22 participating institutions. Patients with presumed candidiasis had a deep-body temperature of 37.8°C or higher and were positive for serum β-D: -glucan or two or more colonization sites of Candida species. The main exclusion criterion was severe renal impairment (creatinine clearance <30 ml/min). The primary efficacy analysis was based on clinical and microbiological responses 5-10 days after the end of treatment, assessed by an independent data review committee. Of the 60 patients enrolled, 49 were included in the modified intention-to-treat population; 31 patients received a definitive diagnosis and 18 patients a presumed diagnosis. Intravenous itraconazole was used as first-line therapy to treat 39 patients and as second-line therapy for 10 patients. The isolated species included Candida albicans (25 strains with definitive diagnosis and 17 with presumed diagnosis) and non-albicans species (16 and 10, respectively). Treatment was successful in 61.5% patients (65.5% in first-line and 50.0% in second-line therapy); 60% of proven invasive candidiasis (IC) patients were judged as successful compared with 63.2% of presumed candidiasis patients. Eradication rate was 63.6% for C. albicans and 71.4% for C. glabrata. Adverse effects occurred in 9 of 60 patients (15.0%), commonly impaired liver function. The clinical efficacy and safety of intravenous itraconazole were suggested in the management of proven and presumed candidiasis including C. glabrata in non-neutropenic patients. The status of intravenous itraconazole in the Japanese guideline warrants reconsideration.     

抗烯醇化酶抗体检测对侵袭性念珠菌病的诊断价值

目的 利用白念珠菌烯醇化酶重组蛋白质为抗原,建立测定人血清中抗白念珠菌烯醇化酶IgG类抗体的ELISA法,评估其在侵袭性念珠菌病(IC)诊断中的应用价值.方法 收集各类确诊IC患者(66例)和白念珠菌定植者(32例)血清,用重组白念珠菌烯醉化酶包被ELISA微孔板,测定血清中的抗烯醇化酶抗体,确定cut off值并对方...     

Candida infections in non-neutropenic children after the neonatal period

There are a variety of diseases, from local mucous membrane infections to invasive systemic infections, that are caused by Candida species. As a causative agent, Candida albicans is the most common; however, the other Candida species can also cause the same clinical syndromes. Most invasive fungal infections in children occur in the hospital setting. Candidemia is a serious condition associated with high morbidity and mortality and increased healthcare costs in pediatric patients. Children at the highest risk are those with prolonged intensive care unit stays, reduced immune function, recent surgery, prior bacterial infection, prior use of antibiotics and/or corticosteroids and other immunosuppressive agents, as well as use of a central venous catheter, total parenteral nutrition, mechanical ventilation and dialysis. Positive blood culture is the gold standard of candidemia; it should not be accepted as contamination or colonization in children with an intravascular catheter. However, in oropharyngeal or vulvovaginal candidiasis, culture of lesions is rarely indicated unless the disease is recalcitrant or recurrent. Recovery of Candida from the sputum should usually be considered as colonization and should not be treated with antifungal therapy. Antigen and antibody detecting tests are evaluated in invasive Candida infections; however, there are no published results in children, and their roles in diagnosis are also unclear. For the therapy of invasive Candida infections in non-neutropenic patients, fluconazole or an echinocandin is usually recommended. Alternatively, amphotericin B deoxycholate or lipid formulations of amphotericin B can also be used. The recommended therapy of Candida meningitis is amphotericin B combined with flucytosine. The combination therapy for Candida infections is usually not indicated. Prophylaxis in non-neonatal, immunocompetent children is not recommended.     

快速乳胶凝集试验在检测外阴和阴道念珠菌感染的应用

目的　评价快速乳胶凝集试验诊断阴道念珠菌病的价值。方法　用乳胶凝集法对临床拟诊念珠菌感染的 119例妇女阴道分泌物进行检测 ,同时与阴道分泌物直接镜检法和培养法相比较。结果　凝集法对阴道念珠菌感染的检出率为 5 8.8% ,高于培养法 (5 6 .3% )和直接镜检法 (31.1% )。与培养法比较 ,快速凝集法的诊断敏感性为 89.6 % ,特异性为 80 .8%。结论　凝集法能快速诊断外阴阴道念珠菌病。虽成本略高于直接镜检法和培养法 ,但凝集法能缩短检测时间 ,且操作简便 ,可对念珠菌感染做初步诊断。     

Value of Candida antigen and antibody assays for the diagnosis of invasive candidosis in surgical intensive care patients

During a 3-year period, a clinical diagnosis of invasive candidosis was made in 8 out of 2054 consecutive surgical intensive care unit (ICU) patients. These patients were retrospectively matched with 16 control patients who underwent similar surgical procedures and had a similar clinical course except for negative Candida cultures. In all patients, Candida antigen (Ramco CandTec serum antigen test) and antibody serology (Candida HA test) were determined at least once a week during their stay. The antigen test was positive in 1/8 patients and 4/16 controls and thus did not differentiate patients with candidosis from non-infected controls. The HA antibody titer results fulfilled the manufacturer's criteria for positivity in 7/8 patients with candidosis and 2/16 control patients. Thus, the Candida HA antibody test, but not the Ramco antigen test, can be recommended to confirm a clinical diagnosis of invasive candidosis.     

Caspofungin susceptibility testing of isolates from patients with esophageal candidiasis or invasive candidiasis: relationship of MIC to treatment outcome

The caspofungin clinical trial database offers an opportunity to assess susceptibility results for Candida pathogens obtained from patients with candidiasis and allows for correlations between efficacy outcomes and MICs. Candida isolates have been identified from patients enrolled in four studies of esophageal candidiasis and two studies of invasive candidiasis. The MICs of caspofungin for all baseline isolates were measured at a central laboratory using NCCLS criteria (document M-27A); MICs for caspofungin were defined as the lowest concentration inhibiting prominent growth at 24 h. MICs were then compared to clinical and microbiological outcomes across the two diseases. Susceptibility testing for caspofungin was performed on 515 unique baseline isolates of Candida spp. obtained from patients with esophageal candidiasis. MICs for caspofungin ranged from 0.008 to 4 microg/ml; the MIC50 and MIC90 were 0.5 and 1.0 microg/ml, respectively. Susceptibility testing was also performed on 231 unique baseline isolates of Candida spp. from patients with invasive candidiasis. The majority (approximately 96%) of MICs were between 0.125 and 2 microg/ml, with MIC50 and MIC90 for caspofungin being 0.5 and 2.0 microg/ml, respectively. Overall, caspofungin demonstrated potent in vitro activity against clinical isolates of Candida species. A relationship between MIC for caspofungin and treatment outcome was not seen for patients with either esophageal candidiasis or invasive candidiasis. Patients with isolates for which the MICs were highest (>2 microg/ml) had better outcomes than patients with isolates for which the MICs were lower (<1 microg/ml). Additionally, no correlation between MIC and outcome was identified for specific Candida species.     

Urine D-arabinitol/L-arabinitol ratio in diagnosing Candida infection in patients with haematological malignancy and HIV infection

Adult patients with hematologic malignancies along with HIV infected patients were prospectively studied to determine the performance of urine D-arabinitol/L-arabinitol (DA/LA) ratio in diagnosing invasive candidiasis. Ten evaluable febrile neutropenic patients had proven invasive candidiasis and elevated DA/LA ratios were found in 5. Invasive candidiasis with normal DA/LA ratios was most frequently due to Candida krusei infection. This Candida species is a non-producer of arabinitol. Only 4 of 81 febrile neutropenic patients given either antifungal prophylaxis or empiric antifungal treatment had elevated DA/LA ratios. Only 1 of 15 HIV positive patients with either oropharyngeal or esophageal candidiasis had elevated DA/LA ratios. Widespread use of fluconazole prophylaxis in bone marrow transplantation patients at the study hospital has led to an increased prevalence of C. krusei infection. This is the likely reason for the low sensitivity of the test in proven and suspected invasive Candida infections reported here.     

The use of hybrid phage displaying antigen epitope and recombinant protein in the diagnosis of systemic Candida albicans infection in rabbits and cancer patients

Hsp90 and Sap2 are 2 immunodominant antigens of Candida albicans. Both of them can induce the production of antibody. In this article, systemically infected rabbits were used to study the Hsp90 and Sap2 antibody production. Also, pET28a-Hsp90 protein, pET28a-Sap2 protein, hybrid phage displaying LKVIRK epitope, and hybrid phage displaying VKYTS epitope were used for diagnosis of the antibody in cancer patients. The results showed that the Sap2 antibody appeared earlier than Hsp90 antibody in systemically infected rabbits. Meanwhile, both of the antibodies can perform protection in rabbits. The conclusion is that Sap2 antibody, which appears at early stage in systemic candidiasis, may be better than Hsp90 antibody for the diagnosis of invasive candidiasis. For 141 sera of cancer patients, 52 sera were detected Sap2 antibody and 57 sera were detected Hsp90 antibody. Only 14 sera contained both the 2 antibodies. Although recombinant protein was slightly more sensitive than hybrid phage, there was no significant difference between them. For its easy preparation, less expensive hybrid phage displaying antigen epitope may be a better agent for diagnosis of candidiasis.     

Esophageal candidiasis. Managing an increasingly prevalent infection

Esophageal candidiasis is an opportunistic infection that is being recognized increasingly often in certain patients, including those who have a neoplastic disease, are undergoing protracted antibiotic therapy, or hae acquired immunodeficiency syndrome (AIDS). Impaired cell-mediated immunity may predispose the patient to esophageal mucosal colonization, whereas chemotherapy-induced granulocytopenia may predispose to disseminated candidiasis. Esophageal candidiasis should be suspected in susceptible patients with complaints of substernal odynophagia or dysphagia. The diagnosis is confirmed by endoscopically directed mucosal biopsy. Esophagitis from other causes (eg. herpes simplex virus, cytomegalovirus, or bacterial infection) may develop concomitantly with esophageal candidiasis. Treatment is determined by the clinical and immune status of the patient. Amphotericin B (Fungizone) is administered to immunocompromised patients at risk for disseminated or deeply invasive candidiasis and is indicated in nongranulocytopenic patients whose symptoms prevent reliable administration of oral antifungal agents. Ketoconazole (Nizoral) may be administered to clinically stable nongranulocytopenic patients with esophageal candidiasis limited to the mucosa. Patients with AIDS and a history of esophageal candidiasis usually benefit from long-term suppression with an oral antifungal agent.     

Esophageal biopsy findings in the acquired immunodeficiency syndrome (AIDS): clinicopathologic correlation in 20 patients

We reviewed 20 esophageal biopsy specimens from 180 adult patients with the acquired immunodeficiency syndrome (AIDS). Ten (50%) showed superficial Candida infection, and four revealed esophagitis due to cytomegalovirus. Candida was never invasive, even though it was associated with significant ulceration. Esophageal candidiasis did not necessarily imply the presence of oral candidiasis, and conversely, oral candidiasis did not imply esophageal candidiasis. Odynophagia was associated with significant histologic ulcerations in eight of ten patients. In the patients who had odynophagia, biopsy was almost equally likely to show Candida or viral cytopathic effect. We discuss the clinicopathologic implications of these findings.     

Early diagnosis of invasive candidiasis with mannan antigenemia and antimannan antibodies

Late treatment of invasive candidiasis (IC) results in severe complications and high mortality. New tools are needed for early diagnosis. We conducted a retrospective study to assess the diagnostic utility of mannan antigenemia (Mn) and antimannan antibodies (anti-Mn) in neutropenic cancer patients at high risk for candidiasis. Twenty-eight patients with IC (based on European Organization for Research and Treatment of Cancer and Mycoses Study Group definitions) and 25 controls were studied. Mn and anti-Mn were positive (> or = 0.25 ng/mL and > or = 5 AU/mL, respectively) in 25/28 (89%) patients with candidiasis and in 4/25 (16%) controls: sensitivity, 89%; specificity, 84%; positive predictive value, 86%; negative predictive value, 88%. In patients with hepatosplenic lesions, assessing Mn/anti-Mn shortened the median time of diagnosis of candidiasis when compared with imaging (9 versus 25 days after fever onset as first sign of infection; P < 0.001). Candidiasis was diagnosed before neutrophil recovery in 78% and 11% of cases with Mn/anti-Mn and radiology, respectively (P < 0.001). Mn and anti-Mn may be useful for early noninvasive diagnosis of IC.     

Evaluation of urinary rapid test for Helicobacter pylori in general practice

There is increasing interest in noninvasive tests for the diagnosis of Helicobacter pylori (H. pylori) infection. One such test, a urine-based rapid test kit (RAPIRUN H. pylori Antibody, Otsuka Pharmaceutical Co., Ltd.) for detection of antibody to H. pylori, has been developed and is considered ideal. In addition to its noninvasiveness and safe handling-due to use of urine as a sample-the assay procedure used for the urinary rapid test is very simple. Only 10-20 minutes are required to complete an assay, and no instruments are needed. The aim of this study was to examine the clinical usefulness of this urine-based rapid test. A total of 189 patients, including 76 patients with gastroduodenal disease, were recruited. A pair of random single-void urine and serum samples was collected from each of the 189 patients, and antibody to H. pylori in the urine and serum samples was measured using the urine-based rapid test kit and three commercially available serum-based ELISA kits. For the patients with gastroduodenal disease, invasive diagnostic methods using endoscopic biopsy specimens such as culture, histology, and rapid urease test were also performed. The sensitivity, specificity, and accuracy of the urinary rapid test were evaluated on the basis of the three serum ELISA results or the invasive diagnostic results. In addition, various urinalyses were performed, and the effects of substances existing in urine on the urinary rapid test results were examined. Of the 189 patients, the urinary rapid test was positive for 110 (58.2%), negative for 78 (41.3%), and invalid for only one patient (0.5%). Based on the three serum-based ELISA results, the sensitivity, specificity, and accuracy of the urinary rapid test were 93.7, 88.9, and 92.2%, respectively. On the basis of the biopsy-based test results, the sensitivity of the urinary rapid test was 100% and its accuracy (95.2%) was equivalent or superior to that of each serum-based ELISA. In addition, no significant differences were observed between groups positive and negative on urinary rapid testing in any urinalysis parameter examined. The novel urinary rapid test kit evaluated in this study enables simple, rapid, and accurate diagnosis of H. pylori infection, and is an ideal test method for point-of-care testing.     

Bench-to-bedside review: <Emphasis Type="Italic">Candida</Emphasis> infections in the intensive care unit

Invasive mycoses are life-threatening opportunistic infections and have emerged as a major cause of morbidity and mortality in critically ill patients. This review focuses on recent advances in our understanding of the epidemiology, diagnosis and management of invasive candidiasis, which is the predominant fungal infection in the intensive care unit setting. Candida spp. are the fourth most common cause of bloodstream infections in the USA, but they are a much less common cause of bloodstream infections in Europe. About one-third of episodes of candidaemia occur in the intensive care unit. Until recently, Candida albicans was by far the predominant species, causing up to two-thirds of all cases of invasive candidiasis. However, a shift toward non-albicans Candida spp., such as C. glabrata and C. krusei, with reduced susceptibility to commonly used antifungal agents, was recently observed. Unfortunately, risk factors and clinical manifestations of candidiasis are not specific, and conventional culture methods such as blood culture systems lack sensitivity. Recent studies have shown that detection of circulating β-glucan, mannan and antimannan antibodies may contribute to diagnosis of invasive candidiasis. Early initiation of appropriate antifungal therapy is essential for reducing the morbidity and mortality of invasive fungal infections. For decades, amphotericin B deoxycholate has been the standard therapy, but it is often poorly tolerated and associated with infusion-related acute reactions and nephrotoxicity. Azoles such as fluconazole and itraconazole provided the first treatment alternatives to amphotericin B for candidiasis. In recent years, several new antifungal agents have become available, offering additional therapeutic options for the management of Candida infections. These include lipid formulations of amphotericin B, new azoles (voriconazole and posaconazole) and echinocandins (caspofungin, micafungin and anidulafungin).     

Undiagnosed invasive candidiasis: incorporating non-culture diagnostics into rational prophylactic and preemptive antifungal strategies

The insensitivity of blood cultures for diagnosing invasive candidiasis fuels prophylactic and preemptive antifungal treatment. Assays like serum β-D-glucan or mannan/anti-mannan detection can identify blood culture-negative invasive candidiasis, but their roles in guiding antifungal therapy are undefined. We propose that non-culture tests can be incorporated into rational management strategies, based on clinical setting. As an example, β-D-glucan sensitivity/specificity for blood culture-negative, deep-seated candidiasis is approximately 60/75%. In intensive care units with <1 or 3% invasive candidiasis rates, positive/negative predictive values are <2/>99% and 6/98%, respectively. With pre-test likelihoods of 10 and 33%, positive/negative predictive values are 20/94% and 54/79%, respectively. Based on these data, negative and positive β-D-glucan results likely will be most useful for discontinuing prophylaxis among low-risk to moderate-risk patients (pre-test likelihoods ～3–10%), and triggering preemptive therapy among moderate-risk to high-risk patients (pre-test likelihoods ～10–25%), respectively. In extremely high-risk patients, universal prophylaxis is likely to be the best strategy.     

Caspofungin for the treatment of less common forms of invasive candidiasis

OBJECTIVES: Caspofungin has demonstrated efficacy in invasive candidiasis. However, in a comparative study, most patients (>83%) had candidaemia. Therefore, we performed a study in patients with non-fungaemic invasive candidiasis. PATIENTS AND METHODS: Adults with proven non-fungaemic invasive candidiasis or probable chronic disseminated candidiasis (CDC) received caspofungin primary or salvage monotherapy. Most patients received 50 mg daily following a 70 mg loading dose. Patients with endocarditis, osteomyelitis or septic arthritis received caspofungin at 100 mg daily and were allowed dose escalation up to 150 mg. Primary efficacy endpoint was the overall response at end of caspofungin therapy. A favourable overall response required complete resolution of symptoms and either eradication of Candida or radiographic resolution. RESULTS: All 48 patients enrolled had confirmed infection and received>or=1 dose of caspofungin. At study entry, 8% were neutropenic. The mean APACHE II score was 14.3. Most infections were due to Candida albicans (60%) or Candida glabrata (14%). The overall success at end of caspofungin therapy was 81%. Success by site of infection was as follows: peritonitis 77% (10/13), abdominal abscess 89% (8/9), CDC 88% (7/8), osteomyelitis/septic arthritis 100% (4/4), endocarditis 33% (1/3) and multiple sites 75% (6/8). Outcomes were similar across Candida spp. None of the patients had a serious drug-related adverse event or discontinued caspofungin due to toxicity. Overall mortality until 12 week follow-up was 23%. CONCLUSIONS: In deep-seated invasive candidiasis, including peritonitis, abdominal abscesses, CDC and arthritis, caspofungin was effective and safe at regular doses and up to 100 mg daily.     

Evaluation of the antigen specific to the mycelial phase of Candida albicans in the serodiagnosis of candidiasis.

We demonstrated 2 different antibodies against Candida albicans in patients' sera, the detection rates were proportional to the severity of candidiasis. One antibody was directed toward antigen shared by Candida in both blastospore and mycelial phases and the other was directed against antigen found only in the mycelial phase of Candida. The presence of the latter may reflect the invasive form of candidiasis.     

The outcome of candiduria in pediatric patients

The presence of Candida in the urine of a seriously ill, pediatric patient presents a management problem because of a lack of information concerning the natural history of candiduria and its relationship to disseminated candidiasis. In this retrospective study, the outcome of candiduria was examined in a group of 54 pediatric patients to determine any predictors of disseminated candidiasis. Medical records were reviewed to identify urine collection methods, Candida colony counts, results of cultures from other body sites, antifungal therapy, and clinical course. Six (11%) of the 54 patients had evidence of systematic Candida infection. In only two of these patients was candiduria the first evidence of disseminated candidiasis. Invasive infection was associated with candiduria more frequently in neonates and patients with central venous catheters and/or immunosuppressive therapy. Urine colony counts were not helpful for assessing the risk of invasive disease. Candiduria appears to be of little consequence in patients who are generally healthy. However, candiduria in high-risk patients, even in the presence of perineal candidal infection or an indwelling urinary catheter, should prompt a careful evaluation for disseminated infection.