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 fatigue. Following a 3-week hospitalization, acute intermittent porphyria was diagnosed based on the symptoms and a high level of urinary delta-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]) subsequently led to the correct diagnosis. No occupational source of lead exposure was identified. The patient reported ingesting a Chinese herbal preparation for 4 weeks prior to becoming ill. A public health investigation revealed that the source of lead exposure was hai ge fen (clamshell 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 blood cells and found that 70% of the patient's cells contained elevated levels of zinc protoporphyrin consistent with the duration of lead exposure and effect of lead on heme synthesis. Analysis of zinc protoporphyrin content in circulating red blood cell distributions may be useful in the diagnosis, therapy, and kinetic modeling of lead poisoning. Environmental lead poisoning is best addressed through the close collaboration of clinicians, public health specialists, and laboratory scientists.