Morbidity and mortality patterns of thalassaemia major patients in Hong Kong: retrospective study.

OBJECTIVES: To study the morbidity and mortality patterns of transfusion-dependent thalassaemia major patients in Hong Kong, and compare the outcomes of these patients according to different periods of birth. DESIGN: Retrospective study. SETTING: Paediatric departments of three regional hospitals, Hong Kong. SUBJECTS AND METHODS: Medical records of thalassaemia major patients were reviewed. Data gathered included demographic and survival data, complications of iron overload, repeated transfusion, and bone marrow transplantation; the probability of survival of three cohorts was also estimated. RESULTS: Two hundred and thirty-two patients were studied at a median age of 15.5 years (range, 1.4-30.3 years). There were 60 patients born before 1980 (cohort 1), 117 patients born between 1980 and 1989 (cohort 2), and 55 patients born after 1989 (cohort 3). The median age of starting desferrioxamine was 8 years, 4 years, and 3 years for cohorts 1, 2, and 3, respectively. Cardiomyopathy, diabetes mellitus, and hypothyroidism occurred in 15.1%, 8.6%, and 6.9% of patients with thalassaemia major, respectively. The above complications developed in 5% to 12% of cohort 2 patients. Delayed puberty was present in 38.4% and hormonal replacement for gonadal failure was required in 29.7% of evaluable patients. Short stature was common and the median height standard deviation score was -1.63. Twenty patients had died, and cardiomyopathy was the leading cause of death, followed by complications of bone marrow transplantation. The probability of survival beyond the age of 20 years was 87.6%. CONCLUSION: Despite the use of iron chelation in the past two decades, severe complications of iron overload still occurred even in those who started chelation therapy early. Cardiomyopathy was the leading cause of death, while endocrinopathies and short stature were common complications especially in teenagers and adults.

Liver disease in transfusion dependent thalassaemia major.

AIMS: To study the prevalence and severity of liver diseases of transfusion dependent thalassaemia major patients, and correlate the histological and biochemical changes of iron overload in liver with the peripheral blood markers. METHOD: Liver biopsy was performed to assess the histological changes and liver iron content (LIC). RESULTS: One hundred patients were evaluated (median age 11.7 years, range 1.5-27). A total of 81 liver biopsies were performed in 73 patients; 43 samples were analysed for LIC. Grade 3-4 haemosiderosis and hepatic fibrosis was found in 44% and 30% of patients respectively; both were significantly associated with higher serum ferritin, liver enzymes, and LIC. Very high LIC (>15 mg/g dry weight) was present in 16.3% of patients. CONCLUSION: Severe haemosiderosis and hepatic fibrosis were common in patients with thalassaemia major despite the use of chelation therapy. Liver biopsy provided information on fibrosis and LIC which could not be accurately predicted from peripheral blood markers.

Incidence, risk factors and outcome of varicella-zoster virus infection in children after haematopoietic stem cell transplantation.

We report a retrospective analysis of VZV infection after haematopoietic stem cell transplantation (HSCT) in children. Thirty-three (30%) of the total 109 children who were transplanted during a 7 year period developed post-transplant VZV infection. Twenty-four of these 33 (73%) children had VZV infection within 1 year following HSCT. The cumulative incidences of post-transplant VZV infection at 1 and 5 years were 26% and 45%, respectively. The positive and negative predictive values of pretransplant VZV serology in recipients on the development of HZ following HSCT were 39% and 88%, respectively. Pretransplant VZV seropositivity in recipients was the only risk factor for post-transplant herpes zoster (HZ) infection on multivariate analysis. All patients responded to acyclovir. The median duration of VZV infection was 5 days. Three (11%) and one (3%) children with HZ developed visceral dissemination and post-herpetic neuralgia, respectively. No mortality was directly attributed to VZV infection. VZV infection remains a major cause of morbidity in children after HSCT. Further studies are warranted to evaluate the potential use of VZV vaccine in these children. Bone Marrow Transplantation (2000) 25, 167-172.