@article{KilercikUcalSerdaretal.2022,
  author    = {Kilercik, Meltem and Ucal, Yasemin and Serdar, Muhittin and Serteser, Mustafa and Ozpinar, Aysel and Schweigert, Florian J.},
  title     = {Zinc protoporphyrin levels in COVID-19 are indicative of iron deficiency and potential predictor of disease severity},
  series = {PLoS ONE},
  volume    = {17},
  journal   = {PLoS ONE},
  number    = {2},
  publisher = {PLOS},
  address   = {San Francisco, California, US},
  issn      = {1932-6203},
  doi       = {10.1371/journal.pone.0262487},
  pages     = {16},
  year      = {2022},
  abstract  = {Background Coronavirus disease (COVID-19) has a severe impact on all aspects of patient care. Among the numerous biomarkers of potential validity for diagnostic and clinical management of COVID-19 are biomarkers at the interface of iron metabolism and inflammation. Methods The follow-up study included 54 hospitalized patients with laboratory-confirmed COVID-19 with a moderate and severe/critical form of the disease. Iron deficiency specific biomarkers such as iron, ferritin, transferrin receptor, hepcidin, and zinc protoporphyrin (ZnPP) as well as relevant markers of inflammation were evaluated twice: in the first five days when the patient was admitted to the hospital and during five to 15 days; and their validity to diagnose iron deficiency was further assessed. The regression and Receiver Operating Characteristics (ROC) analyses were performed to evaluate the prognosis and determine the probability for predicting the severity of the disease in the first five days of COVID-19. Results Based on hemoglobin values, anemia was observed in 21 of 54 patients. Of all iron deficiency anemia-related markers, only ZnPP was significantly elevated (P<0.001) in the anemic group. When patients were grouped according to the severity of disease, slight differences in hemoglobin or other anemia-related parameters could be observed. However, the levels of ZnPP were significantly increased in the severely ill group of patients. The ratio of ZnPP to lymphocyte count (ZnPP/L) had a discrimination power stronger than the neutrophil to lymphocyte count ratio (N/L) to determine disease severity. Additionally, only two markers were independently associated with the severity of COVID-19 in logistic regression analysis; D-dimer (OR (5.606)(95\% CI 1.019-30.867)) and ZnPP/L ratio (OR (74.313) (95\% CI 1.081-5108.103)). Conclusions For the first time ZnPP in COVID-19 patients were reported in this study. Among all iron-related markers tested, ZnPP was the only one that was associated with anemia as based on hemoglobin. The increase in ZnPP might indicate that the underlying cause of anemia in COVID-19 patients is not only due to the inflammation but also of nutritional origin. Additionally, the ZnPP/L ratio might be a valid prognostic marker for the severity of COVID-19.},
  language  = {en}
}
@article{StojanovicErdossyKeltaietal.2017,
  author    = {Stojanovic, Zorica and Erdossy, Julia and Keltai, Katalin and Scheller, Frieder W. and Gyurcsanyi, Robert E.},
  title     = {Electrosynthesized molecularly imprinted polyscopoletin nanofilms for human serum albumin detection},
  series = {Analytica chimica acta : an international journal devoted to all branches of analytical chemistry},
  volume    = {977},
  journal   = {Analytica chimica acta : an international journal devoted to all branches of analytical chemistry},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0003-2670},
  doi       = {10.1016/j.aca.2017.04.043},
  pages     = {1 -- 9},
  year      = {2017},
  abstract  = {Molecularly imprinted polymers (MIPs) rendered selective solely by the imprinting with protein templates lacking of distinctive properties to facilitate strong target-MIP interaction are likely to exhibit medium to low template binding affinities. While this prohibits the use of such MIPs for applications requiring the assessment of very low template concentrations, their implementation for the quantification of high-abundance proteins seems to have a clear niche in the analytical practice. We investigated this opportunity by developing a polyscopoletin-based MIP nanofilm for the electrochemical determination of elevated human serum albumin (HSA) in urine. As reference for a low abundance protein ferritin-MIPs were also prepared by the same procedure. Under optimal conditions, the imprinted sensors gave a linear response to HSA in the concentration range of 20-100 mg/dm(3), and to ferritin in the range of 120-360 mg/dm(3). While as expected the obtained limit of detection was not sufficient to determine endogenous ferritin in plasma, the HSA-sensor was successfully employed to analyse urine samples of patients with albuminuria. The results suggest that MIP-based sensors may be applicable for quantifying high abundance proteins in a clinical setting. (c) 2017 Elsevier B.V. All rights reserved.},
  language  = {en}
}