Efficacy of a hospital policy of selective digestive decontamination for carbapenem-resistant Enterobacterales carriers: prospective before-after study

A single-centre interrupted time series quasi-experimental study was undertaken to assess whether a hospital policy of selective digestive decontamination (SDD, gentamicin/amikacin with neomycin) administered to carbapenem-resistant Enterobacterales (CRE) carriers would reduce the duration of carriage and contain the spread of CRE. No significant difference in time to CRE eradication was observed between the observation (12 months, 120 patients) and intervention (12 months, 101 patients) periods. No change in the trend of new in-hospital CRE acquisitions or bacteraemia during the intervention was detected. As such, administration of SDD to CRE carriers was not effective for the eradication of carriage or controlling in-hospital CRE transmissions.

Concordance between epidemiological evaluation of probability of transmission and whole genome sequence relatedness among hospitalized patients acquiring Klebsiella pneumoniae carbapenemase-producing Klebsiella pneumoniae

OBJECTIVES

We aimed to evaluate the concordance between epidemiologically determined transmission and genetic linkage of Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae (KPC-Kp).

METHODS

We included consecutive KPC-Kp carriers between December 2016 and April 2017 in a hospital endemic for KPC-Kp. We assessed epidemiological relatedness between patients by prospective investigations by the infection control team. The probability of epidemiological relatedness was classified into four groups: no suspected transmission, low, moderate and high probability of transmission. Whole-genome sequencing of isolates was performed. Genetic linkage between KPC-Kp isolates was expressed by distance between isolates in single nucleotide polymorphisms (SNPs). We established an SNP cut-off defining a different strain based on the reconstructed phylogenetic tree. We compared the epidemiological and genetic linkage of all isolates from all patients.

RESULTS

The study included 25 KPC-Kp carriers with 49 isolates. SNP variance was available for 1129 crossed patient-isolate pairs. Genomic linkage, based on a cut-off of 80 SNPs to define related isolates, was found in 115/708 (16.2%) of isolates with no transmission suspected epidemiologically, 27/319 (8.5%) of low, 11/26 (42.3%) of moderate and 64/76 (84.2%) of high epidemiological transmission risk determination (p < 0.001 for trend). Similar results and significant trends were shown on sensitivity analyses using a lower SNP cut-off (six SNPs) and patient-isolate unique pairs, analysing the first isolate from each patient.

CONCLUSIONS

While significant concordance between epidemiological and genomic transmission patterns was found, epidemiological investigations of transmission are limited by the possibility of unidentified transmissions or over-estimation of associations. Genetic linkage analysis is an important aid to epidemiological transmission assessment.

[Pathoanatomical and clinical aspects of the placenta in preterm birth]

BACKGROUND

Prematurely born children show a clearly elevated risk for perinatal morbidity, long-term pediatric morbidities and development of chronic diseases in adulthood compared to babies born at term. The pathoanatomical investigation of placentas from preterm births is useful for assessing the etiology, the risk of recurrence and the prognosis for the child.

AIMS

The focus is on presenting the clinical and pathoanatomical characteristics of acute chorioamnionitis as a frequent cause of preterm induction of labor and pregnancy-induced hypertension, in particular preeclampsia as a frequent reason for elective cesarean section. Other lesions, sometimes of unclear etiology associated with preterm birth and substantially elevated risk of recurrence are reviewed. The clinical correlations and therapeutic options of the various diseases are discussed taking the risk of recurrence into consideration.

MATERIAL AND METHODS

Examination of placentas, association with the clinical course and a literature search.

RESULTS AND DISCUSSION

Acute chorioamnionitis and omphalovasculitis can be histologically subdivided into different stages which correlate with the clinical severity and the prognosis for the newborn child. Chronic deciduitis, chronic chorioamnionitis, villitis of unknown etiology, massive perivillous fibrin deposition and chronic histiocytic intervillositis are entities of unclear etiology associated with recurrent abortion and preterm birth. Autoimmune diseases and thrombophilia are occasionally associated with these pathologically defined lesions. Pregnancy-associated hypertensive disease and particularly preeclampsia as the cause of intrauterine developmental delay and elective cesarean section often show characteristic pathoanatomical placental lesions, which can give indications for the severity and duration of the disease and the prognosis for the child. Early onset (<34 weeks of gestation) and late onset preeclampsia show clinical and morphological differences. Subsequent pregnancies are classified as being at risk and screening for preeclampsia should be clinically performed.

[Clinical and pathological characteristics of intravascular lymphomas]

Intravascular B‑cell lymphomas (IVL) are rare neoplasms that can manifest at any age (mean age ~62-63 years). About half of the cases are associated with Epstein-Barr virus. The most common sites of manifestation are the brain, skin, and bone marrow. The diagnosis is difficult due to unspecific clinical presentation and laboratory changes. FACS (fluorescence-activated cell sorting) and clonality analysis from peripheral blood and radiological findings are often not diagnostic. The most sensitive and most specific diagnostic method is the histopathological and immunohistochemical evaluation of a tissue biopsy. Because of the rarity of this disease, little is known about therapy and prognosis, whereby therapy is mainly similar to non-IVL lymphomas. The prognosis is poor; median survival after diagnosis is approximately one year.

[Reconstruction of the examination of the laryngeal carcinoma of Emperor Frederick III by Rudolf Virchow]

Rudolf Virchow is one of the founders of modern pathology, and many of his ideas on inflammatory and neoplastic diseases are still valid today. Even for Virchow, determination of malignancy was not always easy. As an example, the laryngeal disease of Crown Prince Frederick William, the later Emperor Frederick III, is presented.The clinical findings at the beginning of the disease were suggestive of a carcinoma, though an inflammatory lesion was also discussed. Several attempts were made to remove the lesion bioptically, but local recurrences occurred and the first tissue samples were not examined histopathologically. Since laryngeal tumour operations had a high mortality at that time, histopathologic examinations were made in order to decide for or against an operation. The samples taken after pre-treatment did not meet Virchow's criteria for determining a carcinoma. Contrary to the present concept of a carcinoma in situ-carcinoma sequence, Virchow's concept was based on the assumption that carcinomas are not derived from the epithelium, but arise from a mesenchymal-epithelial transformation from the connective tissue. The clinical suspicion of a laryngeal carcinoma was confirmed only shortly before the patient's death and later by a post-mortem examination.The question repeatedly asked is whether Virchow should have diagnosed a carcinoma at the beginning of the disease. The answer has been the same for more than a hundred years: the clinician is dissatisfied with the histopathological diagnosis, so the pathologist is to blame.

[Analysis of therapy-relevant receptors in bone marrow carcinosis : Comparison of pathological and clinical parameters]

BACKGROUND

Bone marrow carcinosis is a sign of advanced tumor stage with nonspecific clinical and hematological symptoms. Diagnosis is based on bone marrow biopsy and histopathology, but biopsies are not part of the standard work-up in oncological diseases and data on the correlation between clinical presentation and pathological findings are sparse.

MATERIAL AND METHODS

In a retrospective single-center study, data from 20 tumor patients with bone marrow carcinosis were analyzed. Bone marrow biopsies were re-evaluated regarding quantity of tumor cells, fibrosis/necrosis, and bone changes. Immunohistochemistry of potential therapy-relevant receptors and PD-L1 was performed.

RESULTS

The median age in these 20 patients (13 women, 7 men) was 65 years. The most frequent diagnoses were breast (n = 8) and lung cancer (n = 5). Anemia (94% of patients), thrombocytopenia (72%), and elevated LDH (83%) were frequent findings. The degree of bone marrow infiltration was highly variable and accounted for between 1 and 95% of biopsy space. Significant bone remodeling was present in 14/20 biopsies. No correlation could be found between histological and radiological findings. Treated patients showed some clinical and biochemical improvement, but the overall survival was poor (median 4.5 months, range < 0.5 to 21.5 months).

DISCUSSION

Anemia and thrombocytopenia are frequently associated with bone marrow carcinosis, but are nonspecific. The extent of tumor cell infiltration and osteolytic/osteoblastic changes did not correlate with radiological findings. Therapy-relevant target factors should be evaluated, but therapeutic options are often limited and the prognosis is bad.

A human immunodeficiency syndrome caused by mutations in CARMIL2

Human T-cell function is dependent on T-cell antigen receptor (TCR) and co-signalling as evidenced by immunodeficiencies affecting TCR-dependent signalling pathways. Here, we show four human patients with EBV⁺ disseminated smooth muscle tumours that carry two homozygous loss-of-function mutations in the CARMIL2 (RLTPR) gene encoding the capping protein regulator and myosin 1 linker 2. These patients lack regulatory T cells without evidence of organ-specific autoimmunity, and have defective CD28 co-signalling associated with impaired T-cell activation, differentiation and function, as well as perturbed cytoskeletal organization associated with T-cell polarity and migration disorders. Human CARMIL2-deficiency is therefore an autosomal recessive primary immunodeficiency disorder associated with defective CD28-mediated TCR co-signalling and impaired cytoskeletal dynamics.

CARMIL2 (Rltpr) is involved in T-cell function. Here, the authors identify human CARMIL2-deficiency as an autosomal recessive primary immunodeficiency disorder characterized by EBV⁺ smooth muscle tumours, CD28 co-signalling deficiency and impaired cytoskeletal dynamics.

[Necrotizing funisitis : Histopathological indicator of occult congenital syphilis]

Congenital syphilis is a rare disease in central Europe. Placental changes may be non-specific but a typical finding is necrotizing funisitis of the umbilical cord. In a case report we describe how the histopathological incidental finding of B lymphocyte-rich, necrotizing funisitis led to the diagnosis of a previously unknown Treponema pallidum infection in parents and their newborn child. The pathological suspicion of congenital syphilis, although rare, has implications for the clinical management (serological evaluation of parents and child as well as the social environment, evaluation of viral coinfection and treatment decision) and is a notifiable disease.

Carbapenem-resistant Enterobacteriaceae colonization and infection in critically ill patients: a retrospective matched cohort comparison with non-carriers

OBJECTIVES

To examine whether carbapenem-resistant Enterobacteriaceae (CRE) carriage is associated with incidence of clinical infection as a means of assessing whether the morbidity and mortality associated with these bacteria are mediated by underlying conditions or intrinsic properties of CRE.

METHODS

This retrospective matched cohort study compared the incidence of invasive infections in CRE-colonized patients and matched non-carriers in the intensive care unit (ICU). The primary outcome was infection caused by CRE of the same species as the colonizing strain among CRE carriers, and infections caused by carbapenem-sensitive strains of the same organism in non-carriers. Hospital discharge and death were considered as competing events. Competing-risks hazard analysis was performed for the entire cohort and for a nested cohort matched by Acute Physiology and Chronic Health Evaluation (APACHE) II scores, stratified by matching.

RESULTS

In total, 146 CRE carriers were compared with 292 non-carriers. Patients were well matched for most risk factors for Enterobacteriaceae infection, including age, renal failure, previous invasive infection, previous hospitalization, APACHE II score, length of mechanical ventilation, length of hospitalization and CRE carriage. On regression analysis, colonization with CRE was independently associated with Enterobacteriaceae infection {cause-specific hazard ratio (CSHR) 2.06 [95% confidence interval (CI) 1.03-4.09]}. On regression analysis of the APACHE-II-matched cohort (N=284), colonization with CRE remained significantly associated with Enterobacteriaceae infection [CSHR 3.32 (95% CI 1.31-8.43)].

CONCLUSIONS

Colonization with CRE was associated with at least a two-fold increased risk of infection by the colonizing strain amongst ICU patients.

Systematic review of antibiotic consumption in acute care hospitals

Antibiotic consumption is an easily quantifiable performance measure in hospitals and might be used for monitoring. We conducted a review of published studies and online surveillance reports reporting on antibiotic consumption in acute care hospitals between the years 1997 and 2013. A pooled estimate of antibiotic consumption was calculated using a random effects meta-analysis of rates with 95% confidence intervals. Heterogeneity was assessed through subgroup analysis and metaregression. Eighty studies, comprising data from 3130 hospitals, met the inclusion criteria. The pooled rate of hospital-wide consumption was 586 (95% confidence interval 540 to 632) defined daily doses (DDD)/1000 hospital days (HD) for all antibacterials. However, consumption rates were highly heterogeneous. Antibacterial consumption was highest in intensive care units, at 1563 DDD/1000 HD (95% confidence interval 1472 to 1653). Hospital-wide antibacterial consumption was higher in Western Europe and in medium-sized, private and university-affiliated hospitals. The methods of data collection were significantly associated with consumption rates, including data sources, dispensing vs. purchase vs. usage data, counting admission and discharge days and inclusion of low-consumption departments. Heterogeneity remained in all subgroup analyses. Major heterogeneity currently precludes defining acceptable antibiotic consumption ranges in acute care hospitals. Guidelines on antibiotic consumption reporting that will account for case mix and a minimal set of hospital characteristics recommending standardized methods for monitoring and reporting are needed.

Osteocraniosplenic Syndrome-Hypomineralized Skull with Gracile Long Bones and Splenic Hypoplasia: A Case Report and Literature Review

Osteocraniosplenic syndrome-hypomineralized skull with gracile long bones and splenic hypoplasia: a case report and literature review: We report herein an intrauterine growth-restricted preterm nwonate with a lethal bone dysplasia characterized by severe hypomineralization of the skull, absent medullary lucency flared metaphyses fishbone-like diaphysis and overtubulated long vones. Dysmorphic features included flat facies, bulging forehead, vevus flammeus, depressed nasas bridge, short philtrum, inverted U-shape mouth, mild micrometic dwarfism, and brachydactyly. The infant's lungs and spleen were hypoplastic. The findings are compatible with the 19 previously reported cases that used different terminology: osteocraniostenosis, gracile bone disorders and osteocraniosplenic syndrome. We present the clinical, pathological and cytogenetic findings of this rare disorder.

PARTIAL TRISOMY 4p AND PARTIAL MONOSOMY 13q: CASE REPORT AND A LITERATURE REVIEW

We report on a term first born dichorionic-diamniotic twin with deletion of the distal long arm of chromosome 13, partial trisomy of the short arm of chromosome 4, intrauterine growth retardation, and multiple anomalies including microcephaly, colpocephaly, absent corpus callosum, bulbous tip of the nose, large and low set ears, macroglossia, thin upper lip, double outlet right ventricle, atria/ventricular septal defect, cleft mitral valve, pulmonary stenosis, single umbilical artery, multicystic dysplastic left kidney, sacral dimple, anterior displacement of anus, simian creases, abnormal thumb (congenital clasped thumb), overlapping toes, and congenital hypothyroidism. This is the first report of a patient with partial trisomy 4p and partial monosomy 13q.

Partial PTEN deletion is linked to poor prognosis in breast cancer

BACKGROUND

Deletions of chromosome 10q23, including the PTEN (phosphatase and tensin homolog) locus, are known to occur in breast cancer, but systematic analyses of its clinical relevance are lacking.

METHODS

We thus analyzed a tissue microarray (TMA) with 2,197 breast cancers by fluorescence in-situ hybridization (FISH) using a PTEN-specific probe.

RESULTS

PTEN deletions were detected in 19% of no special type, 9% of lobular, 4% of tubular cancers and 46% in carcinomas with medullary features. 98.7% of deletions were heterozygous and only 1.3% were homozygous. PTEN deletion was significantly linked to advanced tumor stage (p=0.0054), high-grade (p<0.0001), high tumor cell proliferation (Ki67 Labeling Index; p<0.0001), and shortened overall survival (p=0.0090). PTEN deletions were inversely associated with features of luminal type breast cancers (ER/PR positivity; p<0.0001 each, and CCND1 amplification; p=0.0020). PTEN deletions were also strongly linked to amplification of genes involved in the PTEN/AKT pathway such as MYC (p=0.0430) and HER2 (p=0.0065). Remarkably the combined analysis of MYC, HER2, CCND1 and PTEN aberrations suggested that aberrations of multiple PTEN/AKT pathway genes have a strong additive effect on breast cancer prognosis. While cancers with one of these aberrations behaved only marginally different from cancers with none, disease outcome was markedly worse in cancers with two or more aberrations as compared to those with only one aberration (p=0.0002). In addition, the particularly poor prognosis of patients with HER2 amplification and PTEN deletions challenges the concept of PTEN deletions interfering with trastuzumab therapy.

CONCLUSION

PTEN deletion occurs in a relevant fraction of breast cancers, and is linked to aggressive tumor behavior. Reduced PTEN function cooperates with MYC and HER2 activation in conferring aggressive phenotype to cancer cells.

Detection and characterization of carbapenemase-producing Enterobacteriaceae in wounded Syrian patients admitted to hospitals in northern Israel

Since 2013, four hospitals in northern Israel have been providing care for Syrian nationals, primarily those wounded in the ongoing civil war. We analyzed carbapenemase-producing Enterobacteriaceae (CPE) isolates obtained from these patients. Isolate identification was performed using the VITEK 2 system. Polymerase chain reaction (PCR) was performed for the presence of bla KPC, bla NDM, and bla OXA-48. Susceptibility testing and genotyping were performed on selected isolates. During the study period, 595 Syrian patients were hospitalized, most of them young men. Thirty-two confirmed CPE isolates were grown from cultures taken from 30 patients. All but five isolates were identified as Klebsiella pneumoniae and Escherichia coli. Nineteen isolates produced NDM and 13 produced OXA-48. Among a further 29 isolates tested, multilocus sequence typing (MLST) showed that ST278 and ST38 were the major sequence types among the NDM-producing K. pneumoniae and OXA-48-producing E. coli isolates, respectively. Most were resistant to all three carbapenems in use in Israel and to gentamicin, but susceptible to colistin and fosfomycin. The source for bacterial acquisition could not be determined; however, some patients admitted to different medical centers were found to carry the same sequence type. CPE containing bla NDM and bla OXA-48 were prevalent among Syrian wounded hospitalized patients in northern Israel. The finding of the same sequence type among patients at different medical centers implies a common, prehospital source for these patients. These findings have implications for public health throughout the region.

8p deletion is strongly linked to poor prognosis in breast cancer

Deletions of chromosome 8p occur frequently in breast cancers, but analyses of its clinical relevance have been limited to small patient cohorts and provided controversial results. A tissue microarray with 2,197 breast cancers was thus analyzed by fluorescence in-situ hybridization using an 8p21 probe in combination with a centromere 8 reference probe. 8p deletions were found in 50% of carcinomas with no special type, 67% of papillary, 28% of tubular, 37% of lobular cancers and 56% of cancers with medullary features. Deletions were always heterozygous. 8p deletion was significantly linked to advanced tumor stage (P < 0.0001), high-grade (P < 0.0001), high tumor cell proliferation (Ki67 Labeling Index; P < 0.0001), and shortened overall survival (P < 0.0001). For example, 8p deletion was seen in 32% of 290 grade 1, 43% of 438 grade 2, and 65% of 427 grade 3 cancers. In addition, 8p deletions were strongly linked to amplification of MYC (P < 0.0001), HER2 (P < 0.0001), and CCND1 (p = 0.001), but inversely associated with ER receptor expression (p = 0.0001). Remarkably, 46.5% of 8p-deleted cancers harbored amplification of at least one of the analyzed genes as compared to 27.5% amplifications in 8p-non-deleted cancers (P < 0.0001). In conclusion, 8p deletion characterizes a subset of particularly aggressive breast cancers. As 8p deletions are easy to analyze, this feature appears to be highly suited for future DNA based prognostic breast cancer panels. The strong link of 8p deletion with various gene amplifications raises the possibility of a role for regulating genomic stability.

A multicenter study of the clonal structure and resistance mechanism of KPC-producing Escherichia coli isolates in Israel

Little is known about the molecular epidemiology of Klebsiella pneumoniae carbapenemase-producing Escherichia coli (KPCEC). We aimed to describe the clonal structure and resistance mechanisms of KPCEC in a multicenter study. The study included 88 isolates from four medical centres in Israel: Tel Aviv Medical Center (n = 17), Laniado Medical Center (n = 12), Sha'are-Zedek Medical Center (n = 38), and Rambam Medical Center (n = 21). Twelve (14%) KPCEC were from clinical sites and 86% from surveillance cultures. The clonal structure was studied by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) and was highly diverse, with 79 and 45 different PFGE types and STs, respectively. The most common clones were ST-131 and ST-410, identified in 21 isolates (23%). Dominant clonal complexes (CCs) were CC131 (n = 16), CC410 (n = 14), CC10 (n = 17), and CC-69 (n = 6). The blaKPC-2 and blaKPC-3 genes were identified in 68 and 20 isolates, respectively. All isolates were non-susceptible to ertapenem; 16 (18%) and 35 (40%) isolates were susceptible (minimal inhibitory concentration ≤1 mg/L) to imipenem and meropenem, respectively. Isolates were susceptible to colistin, amikacin, ciprofloxacin, gentamicin, and trimethoprim-sulfamethoxazole in 100%, 87%, 28%, 27%, and 21% of the cases, respectively. blaKPC-Harbouring plasmids from Tel Aviv Medical Center as well as from six CC-131 isolates from the other centres were studied by Inc and pMLST typing. Sixteen of the 20 blaKPC2-harbouring plasmids were of identical type, IncN-pMLST ST-15. In conclusion, the clonal structure of KPCEC in Israel is characterized by the predominance of known international extended-spectrum β-lactamase-producing clones and by high intra- and inter-institutional diversity. This suggests that in Israel, clonal spread does not play a major role in the dissemination of KPCEC.

Complementary therapies in hemifacial spasm and comparison with other movement disorders

OBJECTIVES

We determined the prevalence, range and factors influencing the use of complementary therapy among hemifacial spasm patients and compared the patterns of use of complementary therapies across different movement disorders in a systematic pooled analysis of published literature.

METHODS

A structured questionnaire was administered to 96 hemifacial spasm patients evaluating frequency of complementary therapy use, and factors influencing patients' decision to seek these therapies. We also performed a PubMed search of epidemiology studies on use of complementary therapies in movement disorders.

RESULTS

Fifty-one per cent of patients had tried complementary therapies, of which 47% reported some perceived benefit and 4.1% informed their doctor. Acupuncture (71.4%) and facial massage (17.6%) were most commonly used. Complementary therapy use was associated with greater HFS severity. The mean cost of treatment was about $78 per month. We identified eight articles on use of complementary therapies in movement disorders; Parkinson's disease (5), Tourette syndrome (2) and dystonia (1). Twenty-five to 88% of patient had tried complementary therapies, of which 32-70% reported some benefit. Trials of acupuncture (2-63%) and massage (7-38%) were reported across the spectrum of movement disorders studied. Mean cost of complementary therapies varied from 43 to 102 USD per month.

CONCLUSION

Complementary therapies are used by over 50% of HFS patients, and the use is correlated with severity of disease. Despite differences in race, culture and population demographics, acupuncture and massage are used by patients across the spectrum of movement disorders.

[Myeloproliferative neoplasms: histopathological and molecular pathological diagnosis]

Myeloproliferative neoplasms (chronic myeloproliferative disorders according to former nomenclature) comprise chronic myeloid leukemia, polycythemia vera, essential thrombocythemia, primary myelofibrosis, chronic eosinophilic leukemia, chronic neutrophilic leukemia and systemic mastocytosis. All disorders have excessive proliferation of one or more hematopoietic lineages in common and progress with different probability to blast crisis or fibrosis. A further common feature is provided by the activating mutation of tyrosin kinases and associated pathways of signal transduction (BCR-ABL, JAK2(V617F), MPL(W515L/K), KIT(D816V) and FIP1L1-PDGFRA) causative for the abnormal proliferation. With regard to diagnosis and therapy these mutations are of utmost importance because they enable the exclusion of reactive processes, contribute with varying specificity to subtyping of MPN and are at least partly sensitive to targeted therapy. The molecular mechanisms of blastic and fibrotic progression are not yet understood.

Impact of carbapenem resistance on the outcome of patients' hospital-acquired bacteraemia caused by Klebsiella pneumoniae

BACKGROUND

Carbapenem-resistant Enterobacteriaceae, especially Klebsiella spp., have become a major health problem recently worldwide. Since 2006 the incidence of carbapenem-resistant Klebsiella pneumoniae (CRKP) infections has increased substantially in Israel. Bloodstream infections (BSIs) caused by these strains have been associated with high rates of treatment failure and mortality.

AIM

This study was designed to identify risk factors for carbapenem resistance among patients with healthcare-related (HCR) K. pneumoniae bacteraemia and predictors of mortality associated with HCR-CRKP bacteraemia compared with carbapenem-susceptible K. pneumoniae (CSKP).

METHODS

In this retrospective case-control study, all cases of K. pneumoniae bacteraemia during 2006-2008 were identified. Resistance patterns, underlying morbidities, risk factors for drug resistance and mortality rates were compared for patients with CRKP and CSKP bacteraemia.

FINDINGS

Two hundred and fourteen patients with CSKP bacteraemia were compared with 103 patients with CRKP bacteraemia. Severe, chronic comorbidities and prior antibiotic use were more frequent among patients with CRKP bacteraemia. On multivariate analysis prior use of macrolides and antibiotic exposure for ≥14 days remained the only independent factors associated with CRKP bacteraemia. Mortality rates of CRKP patients were significantly higher than those of CSKP patients. On multivariate analyses: bedridden status, chronic liver disease, Charlson comorbidity index ≥5, mechanical ventilation, and haemodialysis remained independently associated with mortality among patients with K. pneumoniae bacteraemia. Carbapenem resistance was not a risk factor for mortality.

CONCLUSIONS

Previous antibiotic exposure is a risk factor for CRKP-BSI. Mortality among patients with K. pneumoniae bacteraemia is associated with serious comorbidities, but not with carbapenem resistance.

[Pathobiology of the microRNA system]

MicroRNAs are approximately 22 nucleotides short, non-protein-coding RNA molecules, which bind semi-complementary to mRNA and have an inhibitory effect on protein expression. Aberrant microRNA expression is part of the molecular pathological damage in several degenerative, inflammatory and neoplastic diseases and deregulation can also be virus-associated. Apart from intracellular regulatory functions, microRNA in platelets and exosomes or bound to extracellular protein complexes can also circulate in the blood. Artificial microRNA analogues (small interference RNA/siRNA) and anti-microRNA (antagomir) are used in molecular pathological research of microRNA/mRNA interaction and it is thought that they will also be used as therapeutic agents in the future.

Molecular and clinicopathological analysis of Epstein-Barr virus-associated posttransplant smooth muscle tumors

Epstein-Barr virus (EBV)-associated posttransplant smooth muscle tumors (PTSMT) are very rare complications. We aimed to provide a clinicopathological characterization which is based on our own case series (n = 5) as well as previously reported PTSMT cases (n = 63). Meta-analysis of PTSMT and molecular analysis of tumor cells from our cohort was performed. Most PTSMT developed in kidney-transplanted patients (n = 41/68, 60%). Liver/transplant liver was the main site of manifestation (n = 38/68, 56%). Tumors occurred after a median interval of 48 months (range 5-348) and developed earlier in children than in adults. Most tumors showed no marked cellular atypia, low mitosis rate and no tumor necrosis. Gene expression analysis of 20 EBV-related genes, including two microRNAs, revealed overexpression of MYC (p = 0.0357). Therapy was mainly based on surgical resection or reduced immunosuppression but no significant differences in overall survival were evident. Lower overall survival was associated with multiorgan involvement (n = 33/68, 48.5%) and particularly with intracranial PTSMT manifestation (n = 7/68, 10%; p < 0.02), but not transplant involvement (n = 11/68, 16%). In summary, PTSMT differ from conventional leiomyosarcomas by their lack of marked atypia, unusual sites of involvement and defining EBV association. Surgery and reduced immunosuppression show comparable clinical results and prognosis is associated with intracranial manifestation.

CXCL13 as a novel marker for diagnosis and disease monitoring in pediatric PTLD

Posttransplant lymphoproliferative disease (PTLD) is a severe complication of immunosuppressive treatment in organ-grafted children. Early diagnosis of PTLD is hampered by both unspecific clinical symptoms and lack of easy accessible markers. The homeostatic chemokine CXCL13, which plays a crucial role in B-cell homing and lymphoid organ development, is expressed in some lymphomatous diseases. This study aims to investigate whether serum CXCL13 (sCXCL13) levels correlate with occurrence and regression of PTLD in pediatric solid-organ graft recipients. Serum samples from PTLD patients (n = 21), patients with Epstein-Barr virus (EBV) reactivation (n = 18), and healthy age-matched controls (n = 19) were tested for CXCL13 using a commercially available ELISA kit. sCXCL13 levels were significantly higher in PTLD patients than in healthy children. PTLD patients had also higher sCXCL13 values than pediatric solid-organ recipients with EBV reactivation. An increase in sCXCL13 levels was observed from EBV reactivation to PTLD diagnosis in most cases. Elevated sCXCL13 levels were detected up to 2 years prior to PTLD diagnosis and correlated well with response to cytoreductive treatment in individual patients. sCXCL13, thus, may be a readily available surrogate marker for the diagnosis of PTLD and for monitoring of response to treatment in patients with initially elevated sCXCL13 levels.

JAK2 germline genetic variation affects disease susceptibility in primary myelofibrosis regardless of V617F mutational status: nullizygosity for the JAK2 46/1 haplotype is associated with inferior survival

A common JAK2 germline haplotype (46/1) has been associated with JAK2V617F (VF)-positive myeloproliferative neoplasms. The rs12343867 SNP (C/T) tags this haplotype. A total of 130 patients (77 VF-positive) with primary myelofibrosis (PMF) were analyzed for this informative SNP, using bone marrow-derived DNA. The observed 46/1 C allele frequencies in VF-positive (50%) and VF-negative (36%) patients were both significantly higher than expected in population controls (P<0.01). Genotype distributions in VF-positive/VF-negative patients were CC 31%/9%, CT 38%/53% and TT 31%/38% (P=0.01). CC genotype/C-allele frequencies in patients with <20% VF mutation burden (12%/37%) were similar (P=0.95) to those seen in VF-negative patients (9%/36%), but were significantly lower (P<0.01) than those seen in the presence of >50% mutation burden ( approximately 67%/71%). The rs12343867 genotype did not correlate with the International Prognostic Scoring System (IPSS) score or karyotype. Unexpectedly, the TT genotype was associated with shortened survival (P<0.01), which was not accounted for by IPSS score or VF allele burden. We conclude that JAK2 germline genetic variation affects disease susceptibility, and possibly survival, in PMF, regardless of VF mutational status. Allelic distortion from acquired uniparental disomy contributes to the appearance of a more pronounced effect on disease susceptibility in VF-positive patients, when studying clonally affected tissue.

Modeling, validation and application of a mathematical tissue-equivalent breast phantom for linear slot-scanning digital mammography

This paper presents a mathematical tissue-equivalent breast phantom for linear slot-scanning digital mammography. A recently developed prototype linear slot-scanning digital mammography system was used for model validation; image quality metrics such as image contrast and contrast-to-noise ratio were calculated. The results were in good agreement with values measured using a physical breast-equivalent phantom designed for mammography. The estimated pixel intensity of the mathematical phantom, the analogue-to-digital conversion gain and the detector additive noise showed good agreement with measured values with correlation of nearly 1. An application of the model, to examine the feasibility of using a monochromatic filter for dose reduction and improvement of image quality in slot-scanning digital mammography, is presented.