Sauwalak Opastirakul

Hematological abnormalities in patients with distal renal tubular acidosis and hemoglobinopathies

Mutations of the human SLC4A1 gene encoding erythroid and kidney isoforms of anion exchanger 1 (AE1, band 3) result in erythrocyte abnormalities or distal renal tubular acidosis (dRTA) and such mutations are observed in Southeast Asia, where hemoglobinopathies are prevalent. Genetic and hematological studies in 18 Thai patients with dRTA have shown that 12 of them (67%) carried SLC4A1 mutations (7 G701D/G701D, 3 SAO/G701D, and 2 G701D/A858D). Of these 12 patients, three had homozygous G701D/G701D and heterozygous Hb E; one compound heterozygous SAO/G701D and heterozygous α+‐thalassemia; and one compound heterozygous G701D/A858D and heterozygous Hb E. Of 6 patients without SLC4A1 mutation, two each carried heterozygous or homozygous Hb E and one of the latter also had Hb H disease (‐‐SEA/‐α4.2). The blood smears of patients with homozygous G701D/G701D showed ∼25% ovalocytes. Strikingly, the patients with coexistence of homozygous G701D/G701D and heterozygous Hb E had 58% ovalocytes. Similarly, the patients who had compound heterozygous SAO/G701D showed 49% ovalocytes, but the patient with coexistence of compound heterozygous SAO/G701D and heterozygous α+‐thalassemia had 70% ovalocytes. Our previous study has shown that under metabolic acidosis, the patients with homozygous G701D/G701D or compound heterozygous SAO/G701D had reticulocytosis, indicating compensated hemolysis. A patient with compound heterozygous SAO/G701D and heterozygous α+‐thalassemia presented with hemolytic anemia and hepatosplenomegaly which was alleviated by alkaline therapy. Taken together, the coexistence of both homozygous or compound heterozygous SLC4A1 mutations and hemoglobinopathy has a combined effect on red cell morphology and degree of hemolytic anemia, which is aggravated by acidosis. Am. J. Hematol., 2008.

Steroid-resistant nephrotic syndrome associated with Kimura's disease.

Kimura’s disease is a chronic inflammatory disease characterized by tumor-like lesions in the soft tissue and lymph nodes of head and neck area or parotid gland. It has a high frequency of an association with nephrotic syndrome. Reported cases of nephrotic syndrome and Kimura’s disease were mostly from adult patients with only 5 children mentioned. This study reports the case of a 15-year-old-boy who manifested with steroid-resistant nephrotic syndrome for 4 years. Pathological examination of the kidney revealed mild mesangial proliferation. Subsequently, he developed a soft-tissue mass in the parotid gland area. Histopathological investigation of the mass revealed eosinophilic infiltration together with plasma cells and mast cells which is a main characteristic of Kimura’s disease. The patient, however, continued to have nephrotic-range proteinuria after removing the subcutaneous mass.

Psychosocial functioning of children with systemic lupus erythematosus.

Aims:  Systemic lupus erythematosus (SLE) is a chronic illness in children. Involvement of multiple systems; the chronicity, as well as the treatment, has had great impact on children and their families. The objective of this study was to assess emotional and behavioural problems in childhood lupus during disease remission.

Infantile osteopetrosis in four Thai infants

Four Thai infants, aged between 4 and 23 months, had progressive abdominal distension, pallor and delayed or regressed developmental milestones, with age at onset of 1 month, 3 months, 4 months and 1 month, respectively. Clinical findings consisted of growth and developmental retardation, anemia, frontal bossing, marked hepatosplenomegaly, and hearing and visual impairment. Laboratory findings revealed moderate anemia, leukocytosis and thrombocytopenia. The radiographic findings comprised generalized sclerosis of all bones, including the cranial base, and obliteration of the medullary canals and trabecular patterns. The first and second patients, who had swelling of the wrist joints and prominent costochondral junctions, had hypophosphatemia, elevated levels of serum alkaline phosphatase, and metaphyseal flaring on their radiographs, which was consistent with infantile osteopetrosis complicated by rickets. After Stoss therapy, there were biochemical and radiological responses suggesting vitamin D deficiency in the first patient, but not in the second. The third patient, who had hypocalcemia, hypophosphatemia and normal levels of serum alkaline phosphatase, received vitamin D at 3000 units per day, without improvement. Despite frequent blood transfusions, all patients continued to deteriorate and were finally lost to follow-up. Rickets should be identified and treated at the onset, because treatment of rickets leads to improvement in well-being and an adequate clinical response to bone marrow transplantation.

Pulse cyclophosphamide induction treatment in Thai children with diffuse proliferative lupus nephritis

Aim:  To report the effectiveness of pulse cyclophosphamide induction therapy and to identify predictors for unresponsiveness to treatment in Thai children.