Diagnosis of Invasive Fungal Diseases in Hematological Malignancies: A Critical Review of Evidence and Turkish Expert Opinion (TEO-2)

One of the most problematic issues in hematological malignancies is the diagnosis of invasive fungal diseases. Especially, the difficulty of mycological diagnosis and the necessity of immediate intervention in molds have led to the adoption of “surrogate markers” that do not verify but rather strongly suggest fungal infection. The markers commonly used are galactomannan (GM), beta-glucan, and imaging methods. Although there are numerous studies on these diagnostic approaches, none of these markers serve as a support for the clinician, as is the case in human immunodeficiency virus (HIV) or cytomegalovirus (CMV) infections. This paper has been prepared to explain the diagnostic tests. As molecular tests have not been standardized and are not used routinely in the clinics, they will not be mentioned here.

Saprochaete capitata as an emerging fungus among patients with haematological malignencies

Saprochaete capitata is a very rare pathogen that causes invasive disease particularly in patients with haematological malignancies. We recognised a clustering of S. capitata fungaemia in recent years. So, we report our 6-year surveillance study of fungaemia among patients with haematological malignancies and haematopoietic stem cell transplant. We performed a retrospective and observational study. Hospitalised patients aged >18 years with haematological malignancies were included in the study. A total of 51 fungaemia episodes of 47 patients were analysed. The characteristics of fungaemia in patients with S. capitata compared to patients with candidemia. Median duration of neutropenia was 21.5 days in patients with S. capitata fungaemia, whereas this duration was significantly shorter in patients with candidemia (8 days). Interval between first and last positive culture was significantly longer in patients with S. capitata fungaemia (P < 0.05). Previous use of caspofungin was significantly more common in patients with S. capitata fungaemia. Thirty-day mortality was found 40% for patients with candidemia, whereas it was 39% for patients with S. capitata. In conclusion, despite its limitations this study showed that a novel and more resistant yeast-like pathogen become prevalent due to use of caspofungin in patients with long-lasting neutropenia which was the most noteworthy finding of this 6-year surveillance study.

A nightmare for haematology clinics: extensively drug-resistant (XDR) Acinetobacter baumannnii

The purpose of our study was to share experience on demographic characteristics and clinical outcome of the patients infected with extensively drug-resistant Acinetobacter baumannii (XDRAB) in haematology clinics, focusing on the period with a sudden increase in the number of XDRAB cases. A regular patient-based infection control programme was set up in haematology clinics and haematopoietic stem cell transplant centre starting from 2008. An infection control nurse visited all patients daily. A form including demographic data and laboratory results were recorded for all patients. The source of infections was identified according to the criteria proposed by the Centers for Disease Control and Prevention. While haematology ward-acquired XRDAB was rare before 2012, between January 2012 and July 2013, 29 A. baumannii infection episodes were detected in 28 patients. All but one isolate were MDR and 72.4% (21 out of 29) were XDR. Blood cultures revealed A. baumannii in 26 out of 29 episodes. While the haematological malignancy was relapsing or not under remission in 15 patients, four patients were under remission, and 10 patients were newly diagnosed. The mortality rate was 81.2%. All patients with a poor outcome died in the first week after the index blood culture was performed. In 16 out of 29 episodes, the patients died before the culture results became available. Colistin was initiated for the treatment in 11 out of 29 episodes. Three patients received colistin combined with sulbactam or sulbactam containing beta-lactams; the remaining eight patients who received colistin monotherapy were already under carbapenems. In conclusion, XDRAB infections can easily become nightmares for haematology clinics without any reliable treatment option.

A Single Center Experience for Antifungal Prophylaxis in Patients with Acute Myelogenous Leukemia

We aimed to provide real-life information about the effectivity of different types of primary antifungal prophylaxis (AFP) in patients with acute myeloid leukemia (AML). Records of AML patients who received remission-induction chemotherapy between June 2010 and February 2013 were retrospectively reviewed. A total of 85 AML remission-induction chemotherapy cycles were identified in 80 patients. Fluconazole prophylaxis (FP) was administered in 29 cycles, and posaconazole prophylaxis was given in 56 cycles. Failure in the AFP was observed in 45 (57.9 %) out of 85 cycles. Any type of invasive fungal diseases were detected in 15 (26.8 %) out of 56 cycles receiving posaconazole and 15 (51.7 %) out of 29 cycles receiving fluconazole (p = 0.023). Relapsing or refractory AML, longer duration of neutropenia and FP were more common in patients with AFP failure. Multivariate logistic regression analysis showed that type of AFP (odds ratio (OR) 3.63; 95 % confidence interval (CI) 1.19-11.07), presence of neutropenia longer than 21 days (OR 3.96; 95 % CI 1.36-11.46), and refractory or relapsing AML (OR 6.09; 95 % CI 2.09-17.73) were independent factors associated with failure of AFP. We observed superiority of posaconazole on fluconazole in the prophylaxis of AML patients receiving remission-induction chemotherapy.

Anthrax lethal factor as an immune target in humans and transgenic mice and the impact of HLA polymorphism on CD4+ T cell immunity

Bacillus anthracis produces a binary toxin composed of protective antigen (PA) and one of two subunits, lethal factor (LF) or edema factor (EF). Most studies have concentrated on induction of toxin-specific antibodies as the correlate of protective immunity, in contrast to which understanding of cellular immunity to these toxins and its impact on infection is limited. We characterized CD4⁺ T cell immunity to LF in a panel of humanized HLA-DR and DQ transgenic mice and in naturally exposed patients. As the variation in antigen presentation governed by HLA polymorphism has a major impact on protective immunity to specific epitopes, we examined relative binding affinities of LF peptides to purified HLA class II molecules, identifying those regions likely to be of broad applicability to human immune studies through their ability to bind multiple alleles. Transgenics differing only in their expression of human HLA class II alleles showed a marked hierarchy of immunity to LF. Immunogenicity in HLA transgenics was primarily restricted to epitopes from domains II and IV of LF and promiscuous, dominant epitopes, common to all HLA types, were identified in domain II. The relevance of this model was further demonstrated by the fact that a number of the immunodominant epitopes identified in mice were recognized by T cells from humans previously infected with cutaneous anthrax and from vaccinated individuals. The ability of the identified epitopes to confer protective immunity was demonstrated by lethal anthrax challenge of HLA transgenic mice immunized with a peptide subunit vaccine comprising the immunodominant epitopes that we identified.

Anthrax is of concern with respect to human exposure in endemic regions, concerns about bioterrorism and the considerable global burden of livestock infections. The immunology of this disease remains poorly understood. Vaccination has been based on B. anthracis filtrates or attenuated spore-based vaccines, with more recent trials of next-generation recombinant vaccines. Approaches generally require extensive vaccination regimens and there have been concerns about immunogenicity and adverse reactions. An ongoing need remains for rationally designed, effective and safe anthrax vaccines. The importance of T cell stimulating vaccines is inceasingly recognized. An essential step is an understanding of immunodominant epitopes and their relevance across the diverse HLA immune response genes of human populations. We characterized CD4 T cell immunity to anthrax Lethal Factor (LF), using HLA transgenic mice, as well as testing candidate peptide epitopes for binding to a wide range of HLA alleles. We identified anthrax epitopes, noteworthy in that they elicit exceptionally strong immunity with promiscuous binding across multiple HLA alleles and isotypes. T cell responses in humans exposed to LF through either natural anthrax infection or vaccination were also examined. Epitopes identified as candidates were used to protect HLA transgenic mice from anthrax challenge.

Do we really need ribavirin in the treatment of crimean-congo hemorrhagic Fever?

The role of ribavirin in the treatment of Crimean-Congo hemorrhagic fever (CCHF) is scarce. We retrospectively reviewed treatment features of 81 hospitalized patients with laboratory confirmed CCHF between January 2007 and December 2010. The median age of the patients was 45 years and 47 were male. Out of 81 patients, 6 received ribavirin. Demographic characteristics and laboratory findings of the patients who received ribavirin were not different from the patients who did not receive antiviral. There were no statistically significant difference in duration of symptoms before admission (P = 0·47) between the two groups. Of the patients, 29 who did not receive ribavirin and four from the ribavirin treated group had severe disease based on the Swanpoel criteria (P = 0·22). Two patients from each group died. There was no statistically significant difference in case fatality (P = 0·14) and duration of hospitalization (P = 0·11). Treatment of CCHF without ribavirin seems to be safe based on the findings of this study.

Can low-dose preemptive valganciclovir replace standard intravenous ganciclovir treatment in recipients of allogeneic stem cell transplantation?

The aim of this retrospective study was to compare the efficacy and safety of standard intravenous ganciclovir (GCV) with low-dose oral valganciclovir (VGC) in preemptive treatment of cytomegalovirus (CMV) infection in patients who received allogeneic stem cell transplantation (ASCT). Fifty-nine adult ASCT patients with asymptomatic 68 CMV reactivations were included. For preemptive CMV treatment, VGC (900 mg/day) in 44 reactivations or GCV (5 mg/kg twice daily during the first week and once daily afterwards) in 24 CMV reactivations were administered for 21 days. Two consecutive negative results for PCR and/or CMV antigenemia were considered as treatment success. All patients with CMV reactivations were on immunosuppressive treatment. While no positivity was identified in any of the patients who received GCV on day 21, low-titer CMV positivity was noted in three of the patients in the VGC group (P = 0·264). In all three patients, VGC was continued at same dose and no positivity result was detected after 2-3 weeks. Low-grade neutropenia and high grade thrombocytopenia were significantly higher in the GCV group than in the VGC group (P = 0·018 and P = 0·04 respectively). Preemptive strategy of oral low-dose VGC appears preferable to the prevention of CMV disease in ASCT. These results require confirmation in prospective larger clinical studies.

Clinical presentations and diagnosis of brucellosis

Brucellosis is a worldwide zoonosis caused by Brucella species. The disease remains a significant economic and public health problem particularly in the Mediterranean countries. Clinical manifestations of brucellosis are variable and often nonspecific, simulating infectious and noninfectious diseases. Osteoarticular involvement is the most common focal complication of brucellosis and morbidity. Mortality rate due to brucellosis is low, mostly secondary to endocarditis and central nerve involvement of disease. The diagnosis of brucellosis depends on the clinical presentations and laboratory tests. Detection of Brucella species by culture method is sometimes unsuccessful; therefore, serological tests are preferred. These tests are easy to perform, and results can be obtained within a short span of time. Several serologic tests have been developed for the diagnosis of human brucellosis, including the standard agglutination tube (SAT) test, anti-human globulin (Coombs) test, indirect fluorescence antibody (IFA) test, and enzyme-linked immunosorbent assay (ELISA). SAT is the primary test used in many clinical laboratories. IFA and ELISA are simple and reliable for the detection of immunoglobulin classes especially in complicated cases. Polymerase chain reaction (PCR) technique is highly sensitive and specific for the determination of Brucella spp. from peripheral blood and other tissues. Recent patents are especially based on molecular assays in the diagnosis of brucellosis. However, PCR is still expensive and may not be appropriate for daily practice.

Exposure to anthrax toxin alters human leucocyte expression of anthrax toxin receptor 1

Anthrax is a toxin-mediated disease, the lethal effects of which are initiated by the binding of protective antigen (PA) with one of three reported cell surface toxin receptors (ANTXR). Receptor binding has been shown to influence host susceptibility to the toxins. Despite this crucial role for ANTXR in the outcome of disease, and the reported immunomodulatory consequence of the anthrax toxins during infection, little is known about ANTXR expression on human leucocytes. We characterized the expression levels of ANTXR1 (TEM8) on human leucocytes using flow cytometry. In order to assess the effect of prior toxin exposure on ANTXR1 expression levels, leucocytes from individuals with no known exposure, those exposed to toxin through vaccination and convalescent individuals were analysed. Donors could be defined as either 'low' or 'high' expressers based on the percentage of ANTXR1-positive monocytes detected. Previous exposure to toxins appears to modulate ANTXR1 expression, exposure through active infection being associated with lower receptor expression. A significant correlation between low receptor expression and high anthrax toxin-specific interferon (IFN)-γ responses was observed in previously infected individuals. We propose that there is an attenuation of ANTXR1 expression post-infection which may be a protective mechanism that has evolved to prevent reinfection.

Factors influencing the early mortality in haematological malignancy patients with nosocomial Gram negative bacilli bacteraemia: a retrospective analysis of 154 cases

Background

The aim of this study is to assess the factors influencing the early mortality (7-day after index blood culture) in haematological malignancy patients with Gram negative bacilli (GNB) bacteraemia.

Methods

Infection control committee records were reviewed to identify the cases between March 2006 and June 2011. Only one bacteraemic episode per patient was included in the study.

Results

A total of 154 patients with GNB bacteraemia were identified. The early mortality rate was 19.5% (30 out of 154). Blood cultures revealed Enterobacteriacea in 120 patients (Escherichia coli; 86, Klebsiella spp.; 28, Enterobacter cloacea; 6) and glucose non-fermenting GNB in 34 patients (Pseudomonas aeruginosa; 15, Acinetobacter baumannii; 11, Stenotrophomonas maltophilia; 7, Burkholderia cepacia; 1). Forty (33.3%) out of 120 Enterobacteriaceae were extended spectrum beta-lactamase (ESBL) producers and 18 (52.9%) out of 34 glucose non-fermenting GNB were multidrug resistant. Carbapenems were administered as first line therapy in 139 out of 154 patients. In univariate analysis Pitt's bacteraemia score, presence of aplastic anaemia, bacteraemia caused by glucose non-fermentating GNB, inappropriate empirical antibacterial treatment, presence of severe sepsis or septic shock, unable to achieve microbiological cure, and intensive care unit (ICU) acquired bacteraemia were associated with mortality. Multivariate analysis showed ICU acquired bacteraemia (OR, 12.55; 95% CI, 2.34–67.38, p = 0.003) as an independent factor associated with early mortality.

Conclusion

Haematological malignancy patients who require ICU care are at high risk for early mortality related to GNB bacteraemia. Based on the local findings pointing out high rate of multidrug resistance, carbapenems combined with colistin seems to be a reasonable approach as empirical treatment of these patients. However, increasing carbapenem resistance rate is of concern.

What is the role of the (1→3)-β-D-glucan assay in the screening of patients undergoing autologous haematopoietic stem-cell transplantation?

The aim of this study is to determine the clinical contribution of (1→3)-β-d-glucan (BDG) screening in the case of patients undergoing autologous haematopoietic stem-cell transplantation (HSCT). The records at our stem-cell transplantation centre were reviewed to identify the patients who underwent autologous HSCT between April 2009 and December 2010. Patients were classified as having proven invasive aspergillosis (IA), probable IA, or possible IA on the basis of the criteria established by the European Organization for Research and Treatment of Cancer and Mycoses Study Group (independent of the BDG results). During the study period, the patients were screened for BDG twice a week from transplant (day 0) until engraftment. Three patients were diagnosed with probable IA and five were diagnosed with possible IA. A total of 354 serum samples from 79 patients who met the study inclusion criteria were used for statistical analysis. At the cut-off value of 80 pg ml(-1) , the sensitivity was 27.2% [95% confidence interval (CI); 7.3-60.6]; specificity, 94.4% (95% CI; 91.3-96.5); positive predictive value, 6.2%; and negative predictive, 93.7%. The clinical contribution of the BDG assay as a screening test was relatively limited in this cohort of patients undergoing autologous HSCT.

Naturally Occurring Cutaneous Anthrax: Antibiotic Treatment and Outcome

<i>Objectives:</i> Cutaneous anthrax (CA) is the most common clinical presentation in human anthrax, but the duration of antibiotic therapy in naturally occurring CA is controversial. The aim of this study was to compare the clinical outcomes of patients receiving antibiotic treatment for either 3-5 days (group 1) or 7-10 days (group 2) in uncomplicated CA. <i>Methods:</i> A total of 66 patients were enrolled; 29 (44%) in group 1 and 37 (56%) in group 2. Infections were classified as mild (n = 22, 33%) or severe (n = 44, 67%) CA. <i>Results:</i> There were no significant differences between the groups in symptom resolution time, fever clearance time, healing of lesions, development and healing of eschars, requirement for surgical intervention or the development of complications. Both edema resolution time and duration of hospital stay were longer in group 2. There were no therapeutic failures, relapses or deaths in either group. Steroid therapy was used in 32% of patients with severe CA, but a beneficial effect on resolution of edema was not demonstrated. <i>Conclusions:</i> These results suggest that short-course antibiotic therapy is as effective as standard-duration therapy in uncomplicated CA and that steroid therapy may not be effective.

What should be the optimal cut-off of serum 1,3-β-D-glucan for the detection of invasive pulmonary aspergillosis in patients with haematological malignancies?

BACKGROUND

The detection of 1,3-β-d-glucan (BDG), a cell wall component of several medically important fungi, is a promising tool for the diagnosis of invasive pulmonary aspergillosis. The aim of this study was to evaluate the diagnostic accuracy of the BDG test in invasive pulmonary aspergillosis (IPA) by focusing on the optimal cut-off value.

METHODS

The records of the Infection Control Committee were reviewed to identify patients with haematological malignancies and stem cell transplantation who had at least 1 BDG (Fungitell kit) measurement during the period January 2008 through April 2011. The European Organization for Research and Treatment of Cancer and the Mycoses Study Group (EORTC/MSG) criteria (independent of BDG results) were used to categorize the patients with IPA. Patients with possible IPA were not included in the study.

RESULTS

A total of 128 patients (50 with proven or probable IPA) were included in the study. At the manufacturer's recommended cut-off value of 80 pg/ml, the sensitivity of BDG was 66% (95% CI 51.2-78.7), specificity 75.6% (95% CI 64.6-84.5), positive predictive value (PPV) 63.4%, and negative predictive value (NPV) 77.6%. A receiver operating characteristic (ROC) curve was constructed to define the optimum serum BDG cut-off for the diagnosis of IPA. At a cut-off value of 181 pg/ml, the sensitivity was 52% (95% CI 37.4-66.3), specificity 94.8% (95% CI 87.4-98.6), PPV 86.7%, and NPV 75.5%.

CONCLUSIONS

Although higher cut-off levels increased the specificity of the BDG test, sensitivity decreased to an unacceptable level; the commercially recommended cut-off value appears to be appropriate for screening purposes.

A forgotten diagnosis in emergency department: tetanus

INTRODUCTION

Tetanus is a serious and acute life-threatening disease caused by toxins of "Clostridium tetani". Although it is generally a disease of developing countries, its lower incidence is encountered also in developed countries. Since the principal treatment of this disease is known to be based on vaccination and wound care, the emergency physicians play a key role in its management.

MATERIAL AND METHOD

In the present study, we reviewed its uncommon clinical course along with demographic and clinical features of five cases that have presented with various complaints to our Emergency Department. Presenting signs, demographic features, injury history, and the time from the occurrence of injury to the beginning of symptoms were evaluated.

RESULTS

Four of five cases were female. The mean age of cases was 56.8 (34-73). Three of them had hand injury, one had foot injury, and the fifth case had facial injury. The initial symptoms included difficult jaw movement, back muscle spasm, and pain. Two cases died.

CONCLUSION

Tetanus cases may present to ED with different symptoms. Therefore, physicians should be aware of the early signs of tetanus. Careful and meticulous wound management of cases presented to ED following an injury should be considered a significant factor, which can help in reducing the tetanus cases (Tab. 2, Ref. 18).