Epidemiology of infections in children with acquired aplastic anaemia: a retrospective multicenter study in Italy.

Infection is a significant cause of death in patients with aplastic anaemia (AA). However, few studies have examined the characteristics of infections in patients with AA, especially in children. The aim of this retrospective study was to evaluate the incidence and types of infections in a large cohort of paediatric patients with AA referred to eight AIEOP (Italian Association of Paediatric Oncology and Haematology) centres in Italy. The study included 78 patients, 45 boys and 33 girls, median age 9.29 yrs (1st-3rd quartile 3.59-13.09) diagnosed with AA. During the study period, 111 infectious episodes were observed in 42 (54%) patients. Fifty-one (46%) episodes were fever of unknown origin and 60 (54%) were documented infections (DI). In this group, microbiologically documented infection (MDI) with bacteremia accounted for 23 (38%) episodes, MDI without bacteremia for 7 (12%), clinically documented infection for 25 (42%) and invasive fungal diseases for 5 (8%). The rate (episodes/1000 d at risk) was similar in severe aplastic anemia and very severe aplastic anemia both before and after day 120. During the first 120 d from diagnosis, the cumulative risk of a DI was 21% (95% CI 12-29) with the last episode at day 117, but the 50% of episodes were observed in the first 24 d. After day 120, the cumulative risk of DI was again 21% (95% CI 12-29), with the last episode at day 445 of follow-up, with 50% of episodes observed in the first 120 d of observation (240 d from the diagnosis of AA). We found a statistically significant association between the grade of aplasia at diagnosis and the incidence of IEs (P = 0.0002). No association was found between gender, age at diagnosis, response at day +120 and at day +180, use of G-CSF and occurrence of IEs. The actuarial overall survival at 5 yrs was 90% ± 3.6. The mortality rate attributable to infection complication was 9%. This is a large paediatric cohort study reporting the epidemiology of infectious complications in children with AA and that allow us to compare the epidemiological data in this diseases with that of the most recent studies in neutropenic children with cancer. Our findings confirm that infections represent the main cause of death in patients with AA and they are important for the design of management strategies of febrile neutropenia in these patients.

Diamond-Blackfan anemia: genotype-phenotype correlations in Italian patients with RPL5 and RPL11 mutations.

BACKGROUND: Diamond-Blackfan anemia is a rare, pure red blood cell aplasia of childhood due to an intrinsic defect in erythropoietic progenitors. About 40% of patients display various malformations. Anemia is corrected by steroid treatment in more than 50% of cases; non-responders need chronic transfusions or stem cell transplantation. Defects in the RPS19 gene, encoding the ribosomal protein S19, are the main known cause of Diamond-Blackfan anemia and account for more than 25% of cases. Mutations in RPS24, RPS17, and RPL35A described in a minority of patients show that Diamond-Blackfan anemia is a disorder of ribosome biogenesis. Two new genes (RPL5, RPL11), encoding for ribosomal proteins of the large subunit, have been reported to be involved in a considerable percentage of patients. DESIGN AND METHODS: In this genotype-phenotype analysis we screened the coding sequence and intron-exon boundaries of RPS14, RPS16, RPS24, RPL5, RPL11, and RPL35A in 92 Italian patients with Diamond-Blackfan anemia who were negative for RPS19 mutations. RESULTS: About 20% of the patients screened had mutations in RPL5 or RPL11, and only 1.6% in RPS24. All but three mutations that we report here are new mutations. No mutations were found in RPS14, RPS16, or RPL35A. Remarkably, we observed a higher percentage of somatic malformations in patients with RPL5 and RPL11 mutations. A close association was evident between RPL5 mutations and craniofacial malformations, and between hand malformations and RPL11 mutations. CONCLUSIONS: Mutations in four ribosomal proteins account for around 50% of all cases of Diamond-Blackfan anemia in Italian patients. Genotype-phenotype data suggest that mutation screening should begin with RPL5 and RPL11 in patients with Diamond-Blackfan anemia with malformations.

Changes in cytokine profile pre- and post-immunosuppression in acquired aplastic anemia.

Cytokine expression assessed by flow cytometry in 53 acquired aplastic anemia patients before and after combined immunosuppression (EBMT WPSAA protocols) showed that CD3(+) marrow cells containing TNF-alpha, IFN-gamma and IL4 were similar in subjects with disease at onset (DO) and responsive to treatment who had more CD3(+)/TNF-alpha(+) and CD 3(+)/IFN-gamma(+) cells than normal controls. In vitro block of TNF-alpha and/or IFN-gamma significantly increased BFU-e over baseline in 28 patients. In responsive to treatment patients only TNF-alpha block significantly incremented colonies over normal controls. Absolute marrow CD3(+)/TNF-alpha(+) and CD3(+)/IFN-gamma(+) cells prospectively tested in a group of 21 subjects declined significantly more in Responders than in Non Responders to immunosuppression at Response Evaluation Time respect to Diagnosis. Both in Responders and in Non Responders these cells remained higher than in normal controls. This study suggests that immunosuppression does not fully clear excess TNF-alpha and IFN-gamma from marrow of patients with good outcome and raises the hypothesis that additional cytokine blockade might be useful in immunosuppression for acquired aplastic anemia.

Fanconi anemia patients are more susceptible to infection with tumor virus SV40.

Fanconi anemia (FA) is a recessive DNA repair disease characterized by a high predisposition to developing neoplasms. DNA tumor polyomavirus simian virus 40 (SV40) transforms FA fibroblasts at high efficiency suggesting that FA patients could be highly susceptible to SV40 infection. To test this hypothesis, the large tumor (LT) antigen of SV40, BKV, JCV and Merkel Cell (MC) polyomaviruses were tested in blood samples from 89 FA patients and from 82 of their parents. Two control groups consisting of 47 no-FA patients affected by other genetic bone marrow failure diseases and 91 healthy subjects were also evaluated. Although JCV, BKV and MC were not found in any of the FA samples, the prevalence and viral load of SV40 were higher in FA patients (25%; mean viral load: 1.1×10(2) copies/10(5)cells) as compared with healthy individuals (4.3%; mean viral load: 0.8×10(1) copies/10(5)cells) and genetic controls (0%) (p<0.005). A marked age-dependent frequency of SV40 was found in FA with respect to healthy subjects suggesting that, although acquired early in life, the virus can widespread more easily in specific groups of population. From the analysis of family pedigrees, 60% of the parents of SV40-positive probands were positive for the virus compared to 2% of the parents of the SV40-negative probands (p<0.005). It is worthy of note that the relative frequency of SV40-positive relatives detected in this study was the highest ever reported, showing that asymptomatic FA carriers are also more susceptible to SV40. In conclusion, we favor the hypothesis that SV40 spread could be facilitated by individuals who are genetically more susceptible to infection, such as FA patients. The increased susceptibility to SV40 infection seems to be associated with a specific defect of the immune system which supports a potential interplay of SV40 with an underlying genetic alteration that increases the risk of malignancies.

Central nervous system complications during treatment of acute lymphoblastic leukemia in a single pediatric institution.

Central nervous system (CNS) complications during treatment of childhood acute lymphoblastic leukemia (ALL) remain a challenging clinical problem. Outcome improvement with more intensive chemotherapy has significantly increased the incidence and severity of adverse events. This study analyzed the incidence of neurological complications during ALL treatment in a single pediatric institution, focusing on clinical, radiological, and electrophysiological findings. Exclusion criteria included CNS leukemic infiltration at diagnosis, therapy-related peripheral neuropathy, late-onset encephalopathy, or long-term neurocognitive defects. During a 9-year period, we retrospectively collected 27 neurological events (11%) in as many patients, from 253 children enrolled in the ALL front-line protocol. CNS complications included posterior reversible leukoencephalopathy syndrome (n = 10), stroke (n = 5), temporal lobe epilepsy (n = 2), high-dose methotrexate toxicity (n = 2), syndrome of inappropriate antidiuretic hormone secretion (n = 1), and other unclassified events (n = 7). In conclusion, CNS complications are frequent events during ALL therapy, and require rapid detection and prompt treatment to limit permanent damage.

Efficacy and safety of intrathecal liposomal cytarabine for the treatment of meningeal relapse in acute lymphoblastic leukemia: experience of two pediatric institutions.

The treatment of meningeal relapse in acute lymphoblastic leukemia (ALL) remains a challenging clinical problem. Liposomal cytarabine (DepoCyte) permits to decrease frequency of lumbar punctures, without loss of efficacy, because intrathecal levels of the drug remain cytotoxic for up to 14 days. We investigated the efficacy and safety of intrathecal DepoCyte in six children with meningeal relapse, treated in two pediatric institutions. DepoCyte was well tolerated in all patients, who achieved complete clearance of blasts from the cerebrospinal fluid after the first three intrathecal drug administrations. Five of the six patients were concurrently treated with high-dose administration of systemic cytarabine, without additional neurological side effects. Our results suggest that DepoCyte is a valid option for children with ALL experiencing meningeal relapse; it deserves further investigation in intensive treatment regimens, taking into due consideration potential neurotoxicity.