BackgroundCarbapenem-resistant Klebsiella pneumoniae (CRKP) spread and infections in patients with haematological malignancies are a serious concern especially in endemic areas. Treatment failures and delay in appropriate therapy for CRKP infections are frequent and the mortality rate associated with CRKP bacteremia in neutropenic haematological patients is reported about 60%.MethodsHaematological patients harboring CRKP hospitalized between February 2012 and May 2013 in an Italian Teaching hospital were examined. Conditions favouring CRKP spread in a haematological unit, risk factors for bacteremia in CRKP-carriers and for CRKP bacteremia-related death were evaluated in this observational retrospective study.ResultsCRKP was isolated in 22 patients, 14 (64%) had bacteremia. Control measures implementation, particularly the weekly rectal screening for CRKP performed in all hospitalized patients and contact precautions for CRKP-carriers and newly admitted patients until proved CRKP-negative, reduced significantly the CRKP spread (14 new carriers identified of 131 screened patients vs 5 of 242 after the intervention, p = 0.001). Fifty-eight percent of carriers developed CRKP bacteremia, and acute myeloid leukemia (AML) resulted independently associated with the bacteremia occurrence (p = 0.02). CRKP bacteremias developed mainly during neutropenia (86%) and in CRKP-carriers (79%). CRKP bacteremias were breakthrough in 10 cases (71%). Ten of 14 patient with CRKP bacteremias died (71%) and all had AML. The 70% of fatal bacteremias occurred in patients not yet recognized as CRKP-carriers and 80% were breakthrough. Initial adequate antibiotic therapy resulted the only independent factor able to protect against death (p = 0.02).ConclusionsThe identification of CRKP-carriers is confirmed critical to prevent CRKP spread. AML patients colonized by CRKP resulted at high risk of CRKP-bacteremia and poor outcome and the adequacy of the initial antibiotic therapy may be effective to improve survival. To limit the increase of resistance, the extensive use of antibiotics active against CRKP should be avoided, but in the setting of high CRKP pressure and high-risk CRKP-colonized haematological patients, timely empiric antibiotic combinations active against CRKP could be suggested as treatment of febrile neutropenia.

A clinically driven diagnostic approach in selected neutropenia episodes offered effective antifungal control and reduced the exposure to unnecessary antifungal treatment.

To shed light into the molecular basis of Ph+ acute lymphoblastic leukemia and to investigate the prognostic role of additional genomic lesions, we analyzed copy number aberrations using the Cytoscan HD Array in 116 newly diagnosed adult Ph+ acute lymphoblastic leukemia patients enrolled in four different GIMEMA protocols, all based on a chemotherapy-free induction strategy. This analysis showed that Ph+ acute lymphoblastic leukemia patients carry 7.8 lesions/case on average, with deletions outnumbering gains (88% vs 12%). The most common deletions were those targeting IKZF1, PAX5 and CDKN2A/B detected in 84%, 36% and 32% of cases, respectively. Patients carrying simultaneous deletions of IKZF1 plus CDKN2A/B and/or PAX5 had a significantly worse disease-free survival (24.9% vs 43.3%, p=0.026). The only IKZF1 isoform impacting on prognosis was the dominant negative (p=0.003). Copy number aberrations analysis showed that 18% of patients harbored MEF2C deletions, which were of two types, differing in size: the longer deletions were associated with the achievement of a complete molecular remission (p=0.05) and had a favorable impact on disease-free survival (64.3% vs 32.1% at 36 months, p=0.031). These findings retain statistical significance also in multivariate analysis (p=0.057). KRAS deletions, detected in 6% of cases, were associated with the achievement of a complete molecular remission (p=0.009). These results indicate that in adult Ph+ acute lymphoblastic leukemia a detailed evaluation of additional deletions - including CDKN2A/B, PAX5, IKZF1, MEF2C and KRAS - has prognostic implications and should be incorporated in the design of always more personalized treatment strategies.

PICCs represent a useful and safe alternative to conventional CVAD for the management of patients with hematologic malignancies.