Successful double bone marrow and renal transplantation in a patient with Fanconi anemia.

Parental thiamine 100 mg/d was given. The next day, power of the upper limbs dramatically improved and speech became audible. Over the next 5 days, upper limbs regained full power. As2O3 at 5 mg/d for 28 days as maintenance was given 5 weeks later, with oral thiamine. There was no deterioration in neurology. Lower limb power continuously improved. RBC transketolase during arsenic maintenance was normal, and MRI scan demonstrated complete resolution of all previous abnormalities. Rapidly progressive neuropathy with a dose level of 10 mg/d and cumulative dose of 280 mg As2O3 is unusual. Moreover, recovery of APL subjects from severe neuropathy had been slow in previous arsenic trials.1,2 The rapid improvement in our subject after thiamine administration would not signify a pure arsenic toxicity but would support a contributory role of thiamine deficiency in development of an early severe neurotoxicity during arsenic administration. We have no idea yet whether thiamine or its deficiency has any role in the more frequent but milder form of sensory neuropathy. Yet, we recommend an adequate intake of thiamine during arsenic therapy, and we suggest thiamine deficiency be considered when severe neurotoxicity during arsenic is encountered. We would like to thank Dr Y. L. Kwong and Dr E. S. K. Ma of Queen Mary Hospital, University of Hong Kong, and Dr S. H. Ng of Tuen Mun Hospital for assistance in patient care and for advice. Sze-Fai Yip, Yiu-Ming Yeung, and Edmond-Yik-Kong Tsui