Will bone marrow transplant cure Malignant infantile osteopetrosis?
Q: Is Malignant Infantile Osteopetrosis in a 40 days new born baby girl curable by Bone Marrow Transplant? Is there any future problems like anaemia or body mutilation? How long after the BMT will the child recover or is there any alternative treatment? What is the life span for a baby with this disease without BMT?
A:Malignant infantile osteopetrosis (MIOP) is a rare disease that results in a child having abnormal bones. A normal healthy bone requires a balance between cells laying down bone (osteoblasts) and cells that scavenge it (oseteoclasts). In this disease the osteoclasts function poorly and these children do not have healthy bones which are weak and fracture more easily than normal. The disease usually presents at birth, and during the first few months of life the baby suffers from hypocalcaemia (low blood calcium) that may cause seizures, pressure on the optic nerve in the brain (leading to visual impairment or blindness), and frequent fractures of bones. Other associated problems as a consequence of disease include short stature, dental problems and hearing loss. The life-threatening complication is bone marrow failure due to formation of fibrous tissue. Due to non-functioning osteoclasts, the marrow gets crowded by osteoblasts which prevent it from making the blood cells viz. red cells (anaemia), white blood cells (infections) and platelets (bleeding problems). The prognosis is grave and if left untreated children with malignant infantile osteoporosis do not survive beyond age 10. Treatment modalities include Calcitriol (to stimulate dormant osteoclasts), Erythropoietin (to treat anaemia) and Corticosteroids (to stimulate bone resorption and treating the anaemia). The use of gamma interferon has been shown to produce long-term benefits as it improves white-cell function and reduces bone volume significantly thus increasing in haemoglobin and platelet counts, and, as a result, survival rates. The only potentially curative treatment is an allogeneic haematopoietic stem cell/bone marrow transplant (BMT), using either bone marrow or peripheral blood stem cells. The ideal donor is usually a suitably matched brother/sister. BMT cures both the bone marrow failure and the metabolic disturbances. The survival rate for transplant patients is 40 to 70 percent depending on how well matched the donor is to the patient. BMT also carries considerable risk because of the necessity for profound immunosuppression and the possibility of a graft-versus-host reaction. Children with severely crowded bone marrow appear less likely to benefit and a prior bone biopsy may help in identifying patients who will benefit from it.