Mutational characteristics of ANK1 and SPTB genes in hereditary spherocytosis

The aim of this study was to describe the mutational characteristics in Korean hereditary spherocytosis (HS) patients. Relevant literatures including genetically confirmed cases with well-documented clinical summaries and relevant information were also reviewed to investigate the mutational gene- or domain-specific laboratory and clinical association. Twenty-five HS patients carried one heterozygous mutation of ANK1 (n = 13) or SPTB (n = 12) but not in SPTA1, SLC4A1, or EPB42. Deleterious mutations including frameshift, nonsense, and splice site mutations were identified in 91% (21/23), and non-hotspot mutations were dispersed across multiple exons. Genotype-phenotype correlation was clarified after combined analysis of the cases and the literature review; anemia was most severe in HS patients with mutations on the ANK1 spectrin-binding domain (p < 0.05), and SPTB mutations in HS patients spared the tetramerization domain in which mutations of hereditary elliptocytosis and pyropoikilocytosis are located. Splenectomy (17/75) was more frequent in ANK1 mutant HS (32%) than in HS with SPTB mutation (10%) (p = 0.028). Aplastic crisis occurred in 32.0% of the patients (8/25; 3 ANK1 and 5 SPTB), and parvovirus B19 was detected in 88%. The study clarifies ANK1 or SPTB mutational characteristics in HS Korean patients. The genetic association of laboratory and clinical aspects suggests comprehensive considerations for genetic-based management of HS.

Macrophage activation syndrome in a newborn infant born to a mother with autoimmune disease

Macrophage activation syndrome (MAS) is a complication of rheumatic disorders characterized by cytopenia, multiple organ dysfunction and coagulopathy associated with an inappropriate activation of macrophage. In neonatal lupus erythematosus, MAS is rare but fatal, requiring early diagnosis and treatment for optimal outcome. We report a case of MAS in a neonate born to a mother with autoimmune disease, improved by treatment with steroid, intravenous immunoglobulin and cyclosporine.

FANCA and FANCG are the major Fanconi anemia genes in the Korean population

Fanconi anemia (FA) is a rare disorder characterized by physical abnormalities, bone marrow failure (BMF), increased risk of malignancies, and cellular hypersensitivity to DNA cross-linking agents. This study evaluated the genetic alterations in three major Fanconi genes (FANCA, FANCC, and FANCG) in 30 FA patients using multiplex ligation-dependent probe amplification and direct sequencing. Thirteen BMF patients were genetically classified as FA-A (n = 6, 46%) and FA-G (n = 7, 54%). Four common founder mutations were identified and included two FANCA mutations (c.2546delC and c.3720_3724delAAACA) and two FANCG mutations (c.307+1G>C and c.1066C>T), which had previously been commonly observed in a Japanese FA population. We also detected four novel deleterious mutations: c.2778+1G>C and c.3627-1G>A of FANCA, and c.1589_1591delATA and c.1761-1G>A of FANCG. This study shows that mutations in FANCA and FANCG are common in Korean FA patients and the existence of four common founder mutations in an East Asian FA population. Mutation screening workflow that includes these common mutations may be useful in the creation of an international database, and to better understand the ethnic characteristics of FA.

Clinical characteristics and antibiotic susceptibility of viridans streptococcal bacteremia in children with febrile neutropenia

PURPOSE

This retrospective study was performed in order to investigate the clinical characteristics and antibiotic susceptibility of viridans streptococcal bacteremia (VSB) in febrile neutropenic children in the context of the increase in incidence and antibiotic resistance of VSB.

METHODS

We conducted this study among neutropenic children with underlying hematology/oncology diseases who were diagnosed with VSB at a single institution from April 2009 to June 2012. Clinical and laboratory characteristics of the children as well as antibiotic susceptibility of the causative viridans streptococci were evaluated.

RESULTS

Fifty-seven episodes of VSB were diagnosed in 50 children. Severe complications occurred in four children (7.0%), and a death of one child (1.8%) was attributable to VSB. Acute myeloid leukemia was the most common underlying disease (70.2% of all cases), and 71.9% of all cases received chemotherapy including high-dose cytarabine. VSB occurred at a median of 13 days (range 8-21 days) after the beginning of chemotherapy, and fever lasted for a median of 4 days (range 1-21 days). The C-reactive protein level significantly increased within a week after the occurrence of VSB (p < 0.001) and the maximum C-reactive protein level showed a positive correlation with fever duration (r = 0.362, p = 0.007). Second blood cultures were done before the use of glycopeptides in 33 children, and negative results were observed in 30 children (90.9%). Susceptibilities to cefotaxime, cefepime, and vancomycin were 58.9, 69.1, and 100%, respectively.

CONCLUSIONS

Severe complications of VSB in neutropenic febrile children were rare. We suggest glycopeptide use according to the results of blood culture and antibiotic susceptibility tests based on the susceptibility to cefepime and the microbiologic response to empirical antibiotic treatment not including glycopeptides in this study.

Two children with differing outcomes after treatment for pulmonary tuberculosis diagnosed after allogeneic hematopoietic stem cell transplantation

Tuberculosis (TB) is a rare infectious complication after hematopoietic stem cell transplantation (HSCT), but may be more significant in areas where the disease is endemic. Here, we present the clinical course of 2 children with acute lymphoblastic leukemia who were diagnosed with pulmonary TB after allogeneic HSCT. Both patients were treated for either probable or possible invasive fungal infection, as well as TB. One patient, diagnosed with TB 3 months after HSCT, showed remittent fever and symptoms that progressed to acute respiratory distress syndrome and death, despite 3 modifications to the anti-TB regimen. In contrast, another patient who was diagnosed with TB 8 months after transplantation, responded well to anti-TB medication and completed 1 year of treatment with resolution of lung lesions. Co-morbid opportunistic infections, profound host immunosuppression early after transplantation, and potential risk of multi-drug resistant-TB may act as major barriers to effective treatment of TB after HSCT despite appropriate anti-TB medication.

Effectiveness of rotor off fraction in allogeneic murine bone marrow transplantation with complete disparity of major histocompatibility

Counterflow centrifugal elutriation (CCE) has been a highly efficient physical method for separating T cells from bone marrow (BM) without impairing cell function and yield. To investigate the usefulness of CCE, the hematopoietic potential as well as the level of T cell contamination in rotor-off (R/O) fraction of BM was studied using a murine bone marrow transplantation (BMT) model [C3H/He (H-2k)-->BALB/C (H-2d)]. The total recovery of cells after CCE procedure was 71.4%. Morphologically, R/O fraction contained abundant mononuclear cells and a few lymphocytes. The numbers of colony forming unit for granulocyte/monocyte (CFU-GM), Sca-1+ cells, and T cells were compared among four fractions of CCE (fractions at flow rate of 17, 25, 28 mL/min, and R/O fraction). The number of CFU-GM per 10(5) nucleated cells in each fraction were significantly higher in R/O fraction (331.3 +/- 34.4) compared to unfractionated marrow (UM) (21.1 +/- 1.3) and fraction of 17 mL/min (FR 17) (23.7 +/- 2.2 ) (chi2 = 0.0044). Neither fraction of 25 mL/min (FR 25) nor fraction of 28 mL/min (FR 28) contained CFU-GM colonies. The concentration of Sca-1+ cells in R/O fraction was significantly higher (1.96-fold) than UM (p < 0.05), and 80.0 +/- 10.1% of Sca-1+ cells in UM were recovered in R/O fraction; 88.1% of Thy-1.2+ T cells were eliminated in R/O fraction (p < 0.05). Mice receiving UM after lethal irradiation (875cGy) suffered from severe graft-versus-host disease (GVHD) and all five died within 7 days after BMT procedure (Group A). Of interest, mice receiving mixture of R/O fraction with lymphocyte-rich fraction (FR 25 plus FR 28) to equalize T cell number as UM, developed severe GVHD and four out of five died (probability of survival; 20%) (Group B). Mice receiving R/O fraction had mild GVHD and four out of five survived for at least 90 days (probability of survival; 80%) (Group C). In group C, probability of survival (p = 0.0006) was higher, and severity of GVHD (p = 0.0043) and progression rate of GVHD (p = 0.02) was lower. In conclusion, the elutriated R/O fraction cells of BM have the advantages of stable engraftment and tolerable GVHD in murine allogeneic BMT with complete major histocompatibility disparity. This could be directly applicable to patients with high risk of GVHD and graft failure in upcoming clinical trials.

Pre-emptive ganciclovir treatment can play a role in restoration of hematopoiesis after allogeneic bone marrow transplantation

We performed pre-emptive ganciclovir therapy on two allogeneic bone marrow transplant (BMT) recipients with myelosuppression associated with cytomegalovirus (CMV) antigenemia after successful engraftment. During the hypoplastic phase, the nucleated cells in the bone marrow and peripheral blood were revealed to be of donor origin by DNA fingerprinting. These two patients had CMV antigen in their peripheral leukocytes. Following the pre-emptive ganciclovir treatment, both of them showed gradual recovery of granulocytes and platelets. They are still alive with stable bone marrow function. From these results, we suppose that infection or reactivation of CMV can suppress bone marrow function after bone marrow transplantation, and the pre-emptive ganciclovir therapy based on the CMV antigenemia may be beneficial if bone marrow function deteriorates after engraftment.