Pulmonary biology of anti-interleukin 5 antibodies

Interleukin 5 (IL-5) is a critical cytokine for the maturation of eosinophil precursors to eosinophils in the bone marrow and those eosinophils then accumulate in the lungs during asthma. We have studied anti-bodies on allergic responses in mice, guinea pigs anf monkeys and are extending this experiment into humans with a humanized antibody. In a monkey model of pulmonary inflammation and airway hyperreactivity, we found that the TRFK-5 antibody blocked both responses for three months following a single dose of 0.3 mg/kg i.v. This antibody also blocked lung eosinophilia in mice by inhibiting release from the bone marrow. To facilitate multiple dosing and to reduce immunogenicity in humans, we prepared Sch 55700, humanized antibody against IL-5. Sch 55700 was also active against lung eosinophilia in allergic monkeys and mice and against pulmonary eosinophilia and airway hyperresponsiveness in guinea pigs. Furthermore, as opposed to steroids, Sch 55700 dis not cause immunosuppression in guinea pigs. Studies with antibody in humans will be critical to establishing the therapeutic potential of IL-5 inhibition.

Successful bone marrow transplantation in a Chinese boy with Wiskott-Aldrich syndrome.

We describe the successful use of HLA-compatible sibling bone marrow transplantation (BMT) in a 17-month-old Chinese boy in whom Wiskott-Aldrich syndrome (WAS) was diagnosed on the basis of eczema, thrombocytopenia, recurrent otitis media and abnormal immunological tests. The conditioning chemotherapy included 2 days' oral busulfan, 40 mg/m2/6 hours, and 2 days' intravenous cyclophosphamide, 60 mg/kg/day (BU2CY2). Complete hematological chimerism was achieved 3 weeks after transplantation. Eight months after his BMT the eczema has resolved, platelet count is normal, and he no longer has frequent infections. BU2CY2 as a preconditioning regimen gave complete lymphohematopoietic engraftment in this WAS patient with no evidence of graft-versus-host disease. The excellent clinical response of this patient and the inevitable fatal outcome of WAS support the opinion that where a histocompatible donor is available, BMT at the earliest opportunity is the best option. We believe this is the first case of successful BMT in a Chinese patient with WAS.

Selective IgG subclass deficiencies in patients with recurrent sinopulmonary infections: report of two cases.

Two patients with recurrent sinopulmonary infections and normal total serum immunoglobulin levels were found to have selective deficiencies in IgG subclasses. The serum of one patient contained abnormally low IgG2 and IgG4; and the other was deficient in IgG4. Both patients responded to the treatment with high dose intravenous immunoglobulin. The experiences on these two cases strongly suggest that IgG subclasses should be checked in patients with recurrent sinopulmonary infections in face of normal total immunoglobulins.