LEAD-POISONING DUE TO HAI GE FEN - THE PORPHYRIN CONTENT OF INDIVIDUAL ERYTHROCYTES

A 45-year-old Korean man developed abdominal colic, muscle pain, and f atigue. Following a 3-week hospitalization, acute intermittent porphyr ia was diagnosed based on the symptoms and a high level of urinary del ta-aminolevulinic acid (378 mu mol/L [4.95 mg/dL]). However, discovery of an elevated blood lead level (3.7 mu mol/L [76 mu g/dL]) subsequen tly led to the correct diagnosis. No occupational source of lead expos ure was identified. The patient reported ingesting a Chinese herbal pr eparation for 4 weeks prior to becoming ill. A public health investiga tion revealed that the source of lead exposure was hai ge fen (clamshe ll powder), one of the 36 ingredients of the Chinese herbal medicine. We used fluorescence image-based cytometry to determine the frequency distribution of the zinc protoporphyrin content in circulating red blo od cells and found that 70% of the patient's cells contained elevated levels of zinc protoporphyrin consistent with the duration of lead exp osure and effect of lead on heme synthesis. Analysis of zinc protoporp hyrin content in circulating red blood cell distributions may be usefu l in the diagnosis, therapy, and kinetic modeling of lead poisoning. E nvironmental lead poisoning is best addressed through the close collab oration of clinicians, public health specialists, and laboratory scien tists.