Contributions
Abstract: PB1904
Type: Publication Only
Background
Sideropenic anemia (IDA) is the main cause of anemia worldwide. Even though, its diagnosis is quite straightforward with the use of red blood cell indices, peripheral blood smear (PBS) and ferritin measurements, there are still some pitfalls, namely in the presence of inflammation. The chelation of iron by protoporphyrin constitutes the final reaction of heme biosynthesis. In the absence of iron, zinc becomes an alternative substrate for ferrochelatase leading to the formation of zinc protoporphyrin (ZPP). This compound can be quantified by fluorometry in blood samples, proving itself as a useful and easy parameter for the diagnosis of IDA. However, this technique is not broadly used in the clinical practice.
Aims
Determine the cut-off value of ZPP for the diagnosis of IDA. Evaluate the value of ZPP for the differential diagnosis between IDA and anemia due to inflammatory diseases (AID).
Methods
We have analyzed in our lab, from 1st to 15thFebruary 2017, all the consecutive samples (pediatric and adult) with anemia (as defined by WHO) which had sedimentation rate (SR) and serum ferritin evaluations.
Results
We have identified 204 samples that fulfilled the inclusion criteria: 104 with IDA, 51 with AID and 49 from control patients. IDA group: 73% female (F); mean age 32.3y in F [1.1-78], 28y in males (M) [1-78]; mean Hb was 10.6g/dL [SD 1.4]; mean ferritin was 9.3 ug/L [SD 4.85] and ZPP was 214.1 μmol [SD 121.3]; mean SR was 20.0 mm/h [SD12.9]. AID group: 75% F; mean age 47y in F [2-91] and 22y in M [1-85]. Mean Hb 11.0 g/dL [SD 1.2]; mean ferritin 150.3 μg/L[SD246.2] and ZPP 136.7 μmol [SD 107.8]; mean SR 47mm/h [SD 21]. GC: 69.4% F; mean age 44,8y in F [1.1-79], and 37y in M [2-65 years]; mean Hb 13.8 g/dl [SD 0.9]; mean ferritin 71.9ug/L [SD 49.9] and ZPP 78.6 μmol [SD 26.6]; mean SR 14mm/h [SD 4]. The mean serum ZPP in IDA and AID was significantly higher than in GC (95% CI; p<0.0005). The ROC analysis showed 83.7% sensitivity and 85% of specificity to identify IDA for ZPP ≥100.3 μmol (W=0.933) and 69% sensitivity and 70% of specificity to identify AID for ZPP ≥140 μmol (W=0.749) when compared with GC.
Conclusion
We have concluded that ZPP is a valid, quick, easy and cheap parameter to diagnose IDA in clinical practice, and we have defined in our cohort of patients a ZPP cut off of ≥100.3μmol as diagnostic of IDA with 83.7% sensitivity and 85% of specificity, independent of age. In AID patients we found a cut-off value of ≥140μmol, but with a low sensitivity and specificity. In our study ZPP was not a reliable method to differentiate IDA from AID. This could be due to a sample selection bias (since clinical data were missing and the number of patient with AID was substantially lower than with IDA). It would be important to enlarge the AID sample in order to obtain a more reliable result. Since ZPP measurement can be performed in capillary blood and it is a very quick and cheap method to diagnose IDA, this could be a powerful tool in underdeveloped countries.
Session topic: 28. Iron metabolism, deficiency and overload
Keyword(s): Zinc, Ferritin, Anemia
Abstract: PB1904
Type: Publication Only
Background
Sideropenic anemia (IDA) is the main cause of anemia worldwide. Even though, its diagnosis is quite straightforward with the use of red blood cell indices, peripheral blood smear (PBS) and ferritin measurements, there are still some pitfalls, namely in the presence of inflammation. The chelation of iron by protoporphyrin constitutes the final reaction of heme biosynthesis. In the absence of iron, zinc becomes an alternative substrate for ferrochelatase leading to the formation of zinc protoporphyrin (ZPP). This compound can be quantified by fluorometry in blood samples, proving itself as a useful and easy parameter for the diagnosis of IDA. However, this technique is not broadly used in the clinical practice.
Aims
Determine the cut-off value of ZPP for the diagnosis of IDA. Evaluate the value of ZPP for the differential diagnosis between IDA and anemia due to inflammatory diseases (AID).
Methods
We have analyzed in our lab, from 1st to 15thFebruary 2017, all the consecutive samples (pediatric and adult) with anemia (as defined by WHO) which had sedimentation rate (SR) and serum ferritin evaluations.
Results
We have identified 204 samples that fulfilled the inclusion criteria: 104 with IDA, 51 with AID and 49 from control patients. IDA group: 73% female (F); mean age 32.3y in F [1.1-78], 28y in males (M) [1-78]; mean Hb was 10.6g/dL [SD 1.4]; mean ferritin was 9.3 ug/L [SD 4.85] and ZPP was 214.1 μmol [SD 121.3]; mean SR was 20.0 mm/h [SD12.9]. AID group: 75% F; mean age 47y in F [2-91] and 22y in M [1-85]. Mean Hb 11.0 g/dL [SD 1.2]; mean ferritin 150.3 μg/L[SD246.2] and ZPP 136.7 μmol [SD 107.8]; mean SR 47mm/h [SD 21]. GC: 69.4% F; mean age 44,8y in F [1.1-79], and 37y in M [2-65 years]; mean Hb 13.8 g/dl [SD 0.9]; mean ferritin 71.9ug/L [SD 49.9] and ZPP 78.6 μmol [SD 26.6]; mean SR 14mm/h [SD 4]. The mean serum ZPP in IDA and AID was significantly higher than in GC (95% CI; p<0.0005). The ROC analysis showed 83.7% sensitivity and 85% of specificity to identify IDA for ZPP ≥100.3 μmol (W=0.933) and 69% sensitivity and 70% of specificity to identify AID for ZPP ≥140 μmol (W=0.749) when compared with GC.
Conclusion
We have concluded that ZPP is a valid, quick, easy and cheap parameter to diagnose IDA in clinical practice, and we have defined in our cohort of patients a ZPP cut off of ≥100.3μmol as diagnostic of IDA with 83.7% sensitivity and 85% of specificity, independent of age. In AID patients we found a cut-off value of ≥140μmol, but with a low sensitivity and specificity. In our study ZPP was not a reliable method to differentiate IDA from AID. This could be due to a sample selection bias (since clinical data were missing and the number of patient with AID was substantially lower than with IDA). It would be important to enlarge the AID sample in order to obtain a more reliable result. Since ZPP measurement can be performed in capillary blood and it is a very quick and cheap method to diagnose IDA, this could be a powerful tool in underdeveloped countries.
Session topic: 28. Iron metabolism, deficiency and overload
Keyword(s): Zinc, Ferritin, Anemia