Hepatitis B infection acquired after haematopioetic stem cell transplant through horizontal mode.

A 22 month old child with thalassaemia major received unrelated umbilical cord blood transplantation. She was born to mother of HBsAg carrier and received hepatitis B immunoglobulin at birth and hepatitis B vaccination. She was HBsAg negative and anti-HBs positive before transplantation. After transplant, she was taken care by her mother and found to be HBsAg positive at 2 year post-transplant. Genotyping of the mother's and child's HBV status confirmed to be of same genotype and demonstrated horizontal transmission in post-transplant setting. Passive immunization of HBV may be considered in early post-transplant phase to prevent horizontal transmission of HBV, and antiviral treatment of the carer should be offered to prevent transmission of infection to immunocompromised child.

Malignant pigmented clear cell epithelioid cell tumor (PEComa) in an adolescent boy with widespread metastases: a rare entity in this age group.

Malignant pigmented clear cell epithelioid cell tumor of the kidney is a rare variant of perivascular epithelioid cells tumors (PEComa) or epithelioid angiomyolipoma (AML). PEComa is characteristically composed purely of epitheloid cells. The fat cells and the blood vessels that are typical of classic AML are absent. Most epithelioid AML cases are benign; however, malignant epithelioid AML of the kidney has been occasionally reported in adults in association with tuberous sclerosis. We report the radiological-pathological features of a malignant pigmented clear cell epithelioid renal tumor in a 15-year-old boy presenting with extensive metastases but without clinical evidence of tuberous sclerosis.

Primary pleomorphic liposarcoma of bone in an adolescent: imaging features of a rare entity.

We report a rare case of a primary osseous pleomorphic liposarcoma of the distal femur in a 13-year-old boy. Primary liposarcoma of bone is a very rare malignant tumour originating from primitive mesenchymal cells rather than mature adipose tissue. Pleomorphic liposarcoma is the least common of the eight known histological subtypes in the WHO classification. The entity is not previously reported in children. This is the third reported case of pleomorphic liposarcoma of the bone, and the first reported case presenting in adolescence. We describe the computed tomography and magnetic resonance imaging features of this rare bony tumour.

Renal screening in children after exposure to low dose melamine in Hong Kong: cross sectional study.

OBJECTIVE: To investigate the renal outcomes of children after exposure to low dose melamine in Hong Kong. DESIGN: Cross sectional study. SETTING: Special assessment centres, Hong Kong. PARTICIPANTS: 3170 children (1422 girls and 1748 boys) aged 12 years or less referred from territory-wide primary care clinics after daily consumption for one month or more of milk products tainted with melamine. MAIN OUTCOME MEASURES: Presence of renal stones and haematuria. RESULTS: One child had a confirmed renal stone, seven were suspected of having melamine related renal deposits, and 208 (6.6%) were positive for blood in urine by reagent strip. A proportion of these children were followed up at the special assessment centre, but only 7.4% of those positive for blood on reagent strip were confirmed by microscopy, suggesting an overall estimated prevalence of less than 1% for microscopic haematuria. CONCLUSIONS: No severe adverse renal outcomes, such as acute renal failure or urinary tract obstruction, were detected in children after exposure to low dose melamine. Our results were similar to territory-wide findings in Hong Kong. Even including the seven children with suspected renal deposits, the prevalence of suspected melamine related abnormalities on ultrasonography was only 0.2%. None of these children required specific treatment. The prevalence of microscopic haematuria was probably overestimated by the reagent strip. These data suggest that large scale and urgent screening programmes may not be informative or cost effective for populations who have been exposed to low dose melamine.

Outcome of intensive care of homozygous alpha-thalassaemia without prior intra-uterine therapy.

AIM: To review the outcome of homozygous alpha-thalassaemia without prior intra-uterine therapy treated in neonatal intensive care unit and identify the factors associated with survival. METHODS: The hospital records of all patients with homozygous alpha-thalassaemia treated in our neonatal intensive care unit in the last 15 years were reviewed. A literature search beginning in the year 1980 was done to identify homozygous alpha-thalassaemia actively treated in neonatal intensive care units. Those receiving prior intra-uterine therapy were excluded. The following information was collected: the severity of hydrops, sizes of liver and spleen, haemoglobin level, Apgar score at 5 min, ventilator settings, timing and forms of red blood cell transfusion and presence of persistent hypoxaemia. The survivors and the non-survivors were compared. RESULTS: In our centre, in the last 15 years there were six infants born with homozygous alpha-thalassaemia who did not receive intra-uterine therapy; one survived and five succumbed despite aggressive respiratory therapy. In our literature search there were more reports of survivors (10) than non-survivors (six) for these infants, suggesting a reporting bias towards selection of rare cases of survival. Apgar score of four or above occurred in seven of the eight survivors with data available in the reports, whereas this occurred in four of the 11 non-survivors (P = 0.035, Fisher Exact test). Five of the 11 survivors had abnormal neurological outcome including developmental delay and spastic quadriplegia. CONCLUSION: Without prior intra-uterine therapy, homozygous alpha-thalassaemia has grave outlook in terms of mortality and morbidity despite aggressive respiratory therapy.

Inflammatory cytokine profile in children with severe acute respiratory syndrome.

OBJECTIVE: To study the inflammatory cytokine profile in children with severe acute respiratory syndrome (SARS) and to investigate whether monoclonal antibody to tumor necrosis factor-alpha (TNF-alpha) could be considered for treatment of these patients. METHODS: Plasma inflammatory cytokine concentrations (interleukin [IL]-1beta, IL-6, IL-8, IL-10, IL-12p70, and TNF-alpha) were monitored longitudinally on admission, immediately before corticosteroids, and 1 to 2 days and 7 to 10 days after the drug treatment in a cohort of pediatric patients (n = 8) with virologic confirmed SARS-associated coronavirus infection. None of the patients required mechanical ventilation or intensive care treatment. All children except 1 (patient 3) received corticosteroids. RESULTS: Plasma IL-1beta levels (excluding patient 3) were substantially elevated immediately before (range: 7-721 ng/L) and 7 to 10 days after (range: 7-664 ng/L) corticosteroid treatment. In contrast, the plasma concentrations of other key proinflammatory cytokines, including IL-6 and TNF-alpha, were not overtly increased in any of the patients throughout the course of illness. In addition, plasma IL-10 concentration was significantly lower 1 to 2 days and 7 to 10 days after corticosteroid treatment, compared with the immediate pretreatment level. Similarly, plasma IL-6 and IL-8 concentrations were significantly decreased 7 to 10 days after the drug treatment. CONCLUSIONS: Pediatric SARS patients have markedly elevated circulating IL-1beta levels, which suggests selective activation of the caspase-1-dependent pathway. Other key proinflammatory cytokines, IL-6 and TNF-alpha, showed only mildly elevated levels at the initial phase of the illness. The current evidence does not support the use of TNF-alpha monoclonal antibody in this group of children.