And the Oscar Goes to Peripheral Blood Film for the Detection of Lead Poisoning in a Complicated Toxic Patient: A Case Report with a Review of Laboratory Clues

Table 2

Change of different laboratory tests in lead poisoning.

Test	Specimen	Diagnostic clue	Mechanism
HB	Whole blood	Decreased	Microcytic and hemolytic anemia [5]
MCV	Whole blood	Decreased	Iron incorporation into heme is impaired [5]
MCH	Whole blood	Decreased	Iron incorporation into heme is impaired [5]
PBS	Whole blood	Coarse basophilic stippling—Cabot rings	Instability of RNA and remaining microtubules, respectively, due to abnormal erythropoiesis [5]
Reticulocyte count	Whole blood	Increased	Hemolytic anemia due to the inhibition of Na-K-dependent ATPases in cell membranes and increased fragility [12]
BM iron stain	BM aspiration smear	Ring sideroblasts	Iron accumulation in the mitochondria [12]
Blood lead level	Whole blood	Increased
Zinc protoporphyrin	Whole blood	Increased	Zinc protoporphyrin is formed instead of heme [12]
Free red cell protoporphyrin	Whole blood	Increased	It is a product of zinc protoporphyrin [12]
LDH	Serum/plasma	Increased	Hemolytic anemia [14]
AST/ALT	Serum/plasma	Increased	Increasing oxidative stress [15]
BUN/Cr	Serum/plasma	Increased	Proximal tubular dysfunction and Fanconi-type syndrome [16]
Urine glucose	Urine	Increased (positive)	Proximal tubular dysfunction and Fanconi-type syndrome [16]

indicates not applicable. HB: hemoglobin; MCV: mean corpuscular volume; MCH: mean corpuscular hemoglobin; PBS: peripheral blood smear; BM: bone marrow; LDH: lactate dehydrogenase; AST: aspartate aminotransferase; ALT: alanine aminotransferase; BUN: blood urea nitrogen; Cr: creatinine.