I-Anne Huang

The role of Helicobacter pylori infection in children with acute immune thrombocytopenic purpura

The outcome of immune thrombocytopenic purpura (ITP) is classified as acute or chronic depending on whether platelet count returns to normal. The prevalence of Helicobacter pylori infection increases with age and is independent of gender. We investigated the prevalence of H. pylori infection in Chinese children from Northern Taiwan and analyzed the association between H. pylori infection and acute ITP. Our prospective cohort studies found no statistically significant relation between H. pylori infection and acute ITP. There is therefore no indication to screen children with presumed acute ITP for H. pylori infection.

Successful unrelated mismatched cord blood transplantation in a child with malignant infantile osteopetrosis

Abstract:  Allogeneic hematopoietic stem cell transplantation represents the only curative option for malignant infantile osteopetrosis (MIOP), a rare disease of infants and young children, characterized by excessive accumulation of mineralized bone and abnormal hematopoiesis. We report a case of successful engraftment and stable full‐donor chimerism in a patient with MIOP who underwent unrelated donor cord blood transplantation (CBT). The donor was 2‐loci human leukocyte antigen (HLA)‐mismatch. After a conditioning regimen based on the combination of busulfan, cyclophosphamide, total body irradiation, and antithymocyte globulin, the patient received a dose of 3.85 × 107/kg of nucleated cells. Neutrophil and platelet engraftment had been achieved by day +33 and +82, respectively, and the patient was discharged home on day +89. A successful engraftment of donor hematopoiesis was demonstrated and the child experienced grade II acute graft‐vs.‐host disease (GVHD) involving the skin only. A remarkable but non‐progressive decrease in lumbar spine bone mineral density was observed in the first nine months post‐transplant. This case suggests that unrelated donor CBT may be a feasible option in case of unavailability of a fully HLA‐matched related or unrelated donor.

Outcome of Long-Term Mechanical Ventilation Support in Children

BACKGROUND Improved technology and care in recent years have significantly improved the prognosis and quality of life for patients on long-term mechanical ventilation. This study examined the status of children on long-term mechanical ventilation (MV) support in Taiwan. METHODS The medical records of patients between January 1998 and December 2006 were retrospectively reviewed, and the clinical factors were systematically reviewed. RESULTS One hundred and thirty-nine (139) patients aged 3 months to 18 years, with 53 (38.1%) girls and 86 (61.9%) boys, were enrolled. The common underlying disorders included neurologic/neuromuscular diseases (n=100, 71.9%) and airway/lung dysfunction (n=19, 13.7%). After instituting MV, the children returned to the medical center mainly for infection (n=157, 47.7%) and elective surgery or procedures (n=46, 13.9%). After long-term follow-up, 37 (26.6%) died, 81 (58.3%) were transferred to respiratory care wards in local hospitals, and 21 (15.1%) received home care support. CONCLUSIONS There are now more children on long-term MV support in Taiwan and most are in respiratory care wards in local hospitals. The shift in underlying diagnoses from pulmonary disease to neurogenic respiratory insufficiency affects hospitalization. The main cause of respiratory insufficiency is neurologic insult.

Cord blood transplantation in children with relapsed or refractory severe aplastic anemia.

Early results of cord blood transplantation (CBT) for severe aplastic anemia were poor with a high rate of engraftment failure. We carried out CBT in 5 children with relapsed or refractory severe aplastic anemia, using immunosuppressive preparative regimens. The median time from the diagnosis to the CBT was 16 months (15 to 47 mo), with all the children having failed at least 1 course of immunosuppressive therapy. The conditioning regimens consisted of fludarabine, cyclophosphamide, and antithymocyte globulin. One patient had an HLA-identical sibling donor, and 4 had unrelated donors selected from an NMDP-affiliated cord blood bank. Two patients received double-unit grafts to attain a target TNC dose of at least 3.0×107/kg. Donor/recipient HLA matching was 6 of 6 (n=2) and 5 of 6 (n=5). The median nucleated cell dose infused was 5.6 (range, 3.6 to 6.1) ×107 cells/kg. The median infused CD34 dose was 2.9 (range, 1.8 to 7.5) ×105 cells/kg. All the patients achieved neutrophil engraftment at a median of 13 days (range, 11 to 25 d). The median time to platelet engraftment was 48 days (range, 34 to 56 d). After CBT, acute GVHD developed in 4 cases, CMV reactivation in 1, pneumonia in 1, and sepsis in 1. Four patients successfully engrafted, but 1 failed to engraft and had delayed autologous recovery. However, all patients were now transfusion-independent at the time of reporting. This result suggests that CBT using optimal conditioning regimens can be a salvage treatment for patients without a suitable bone marrow donor and warrants further prospective studies.

Combined chemotherapy and tracheobronchial stenting for life-threatening airway obstruction in a child with endobronchial non-Hodgkin lymphoma

Endobronchial involvement in non-Hodgkin lymphoma is rare even in the presence of advanced disease. A 15-year-old boy presented with progressively worsening dyspnea with occasional hemoptysis for 1 week prior to admission. Three days later, he was intubated due severe dyspnea with complete atelectasis of the right lung. Fiberoptic bronchoscopy disclosed an endobronchial mass almost occupying the right main bronchus. He underwent partial resection of the endobronchial tumor with rigid bronchoscopy. An airway stenting was used in this patient because he had severe tracheal obstruction from the tumor. The compromised airway was alleviated by combined chemotherapy and tracheobronchial stenting.

Single-center experience: Immunosuppressive therapy as frontline treatment for 33 children with acquired severe aplastic anemia

The authors retrospectively analyzed the records of 33 children with acquired severe aplastic anemia (SAA) diagnosed from July 1998 to October 2007 and first treated by immunosuppressive therapy (IST). Serial hematologic parameters, complications, transfusion requirements, and time to response were assessed. Allogeneic hematopoietic stem cell transplantation (HSCT) was attempted in 7 patients after failure of IST (n = 6) or relapse following an initial response to IST (n = 1). One child died of post-transplant lymphoproliferative disorder. Thirty of the 33 patients are alive and well after a median follow-up of 45 months (range, 7–116 months). Overall (transfusion-independent) response to IST was 73% (24/33). The actuarial 5 years survival rate was 89.4%. In this study, all patients with SAA received IST as standard front-line therapy. Approximately three-fourths of patients with SAA have durable recovery and excellent overall survival.

Risk factor analysis of autoimmune hemolytic anemia after allogeneic hematopoietic stem cell transplantation in children

AbstractAutoimmune hemolytic anemia (AIHA) is a clinically relevant complication after allogeneic hematopoietic stem cell transplantation (HSCT). Currently, there is no established consensus regarding the optimal therapeutic approach. Whether AIHA contributes to increased mortality is still somewhat controversial.We investigated the incidence, risk factors, and outcome of post-transplant AIHA in 265 consecutive pediatric patients undergoing allo-HSCT over a 17-year period. Onset of AIHA was calculated from the first documented detection of AIHA by either clinical symptoms or positive direct agglutinin test. Resolution of AIHA was defined as normalization of hemoglobin and biochemical markers of hemolysis with sustained transfusion independence.We identified 15 cases of AIHA after allo-HSCT (incidence rate, 6%). Ten (67%) of these patients had a positive direct antiglobulin test. Data were obtained for 9 boys and 6 girls after a median follow-up of 53 months (range 4–102). The median age was 5.1 years (range 0.5–15.4) at the time of HSCT and the median time to emergence was 149 days (range 42–273). No significant risk factor for post-transplant AIHA has emerged from our data to date. In the majority (14 of 15; 93%) of AIHA patients, multiple agents for treatment were required, with 12 of 15 (80%) patients achieving complete resolution of AIHA. No splenectomy was performed in any of our patients.For various reasons, post-transplantation AIHA poses an extraordinary challenge to transplant physicians. Despite the advancements in diagnostic tools, therapeutic challenges remain due to the myriad interacting pathways in AIHA.

Complicated features in a young child with influenza B virus pneumonia and co-infection with Stenotrophomonas maltophilia

Abstract A 3·5-year-old child with influenza B virus pneumonia developed pneumomediastinum and subcutaneous emphysema on the 3rd day of illness. Bronchoscopy demonstrated obstruction of the left main bronchus by mucopurulent sputum. Culture of the broncho-alveolar lavage yielded Stenotrophomonas maltophilia. After the respiratory complications resolved (11 days), the patient developed neurological symptoms and was diagnosed as acute disseminated encephalomyelitis (ADEM). Stenotrophomonas maltophilia was probably a factor in the development of pneumomediastinum. To our knowledge, this is the first case report of influenza virus infection with Stenotrophomonas maltophilia co-infection associated with spontaneous pneumomediastinum.

Guillain-Barré syndrome presenting as mimicking croup

Stridor is a commonly encountered presenting symptom of upper airway obstruction in the pediatric population. Although infection etiologies such as croup, retropharyngeal abscess, and epiglottitis predominate in the pediatric population, other less common etiologies must also be considered in the differential diagnosis. We report a case of 3-year-2-month-old girl who exhibited the following symptoms: progressive hoarseness, backing cough, and dyspnea. Initial clinical symptoms were mimicking croup. After admission, she developed progressive muscle weakness and areflexia. Flexible laryngoscopy showed bilateral vocal cord paralysis. Finally, she was diagnosed with Guillain-Barré syndrome (GBS). We emphasized that the early recognition of atypical presentations of GBS warrants further evaluation and appropriate management.

Magnetic resonance abnormalities of bone marrow in a case of acute lymphoblastic leukemia.

Although magnetic resonance imaging (MRI) is not performed routinely in the diagnostic work-up of children with leukemia, patients may present with a normal peripheral blood cell count and osteological manifestations. For such cases, MRI may be requested in the early workup for a diagnosis. This situation illustrates that a delay in appropriate diagnosis may occur, with the classic features of the disease being uniformly absent. We present a child illustrating the salient features of acute leukemia upon MRI with limb pain and an initial normal peripheral blood cell count.