Role of oral lactoferrin as a source of iron supplementation in correction of anemia in pediatric patients with chronic kidney disease stages 2–4

Mohamed S El-Farsy; Ihab Z El-Hakim; Rawan A Al-Arian

doi:10.4103/jesnt.jesnt_22_21

ORIGINAL ARTICLE

Year : 2022 | Volume : 22 | Issue : 4 | Page : 193-199

Role of oral lactoferrin as a source of iron supplementation in correction of anemia in pediatric patients with chronic kidney disease stages 2–4

Mohamed S El-Farsy¹, Ihab Z El-Hakim¹, Rawan A Al-Arian²
¹ Department of Pediatrics, Faculty of Medicine, Ain Shams University, Cairo, Egypt
² Ministry of Health, Cairo, Egypt

Date of Submission	26-Aug-2021
Date of Acceptance	08-Mar-2022
Date of Web Publication	22-Sep-2022

Correspondence Address:
Dr. Mohamed S El-Farsy
Department of Pediatrics, Faculty of Medicine, Ain Shams University Children’s Hospital, PO Box 11566, Abbassyia, Cairo
Egypt

Source of Support: None, Conflict of Interest: None

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DOI: 10.4103/jesnt.jesnt_22_21

Abstract

Background Children with chronic kidney disease (CKD) have multiple risk factors for anemia such as primary erythropoietin deficiency, blood loss, decreased red blood cell (RBC) survival, bone marrow suppression, iron deficiency, inflammation and infection, malnutrition, hyperparathyroidism, vitamin B12 and folate deficiency, aluminum toxicity, and carnitine deficiency. This study was performed to evaluate the effect of oral bovine lactoferrin on patients with iron deficiency with CKD stages 2–4. Patients and methods This follow-up cohort clinical study was conducted on children with CKD in the conservative clinic, Pediatric Nephrology Unit, Children’s Hospital, Ain Shams University. It included 45 pediatric patients with CKD stages from 2 to 4 for 6 months without a control group. This is a follow-up case study in which all the included patients were on erythropoietin therapy ranging from 150 to 300 IU/kg once per week. The patients were subjected to history and laboratory evaluation, including hemoglobin (Hb), serum iron, serum ferritin, and total iron-binding capacity (TIBC), which were done for the patients at baseline and 6 months after treatment with bovine lactoferrin for 6 months. Results Blood Hb and RBC volume were significantly increased beginning from first month after oral lactoferrin therapy, serum iron and serum ferritin were significantly increased 6 months after intervention, and serum TIBC was significantly decreased after intervention. The current study had shown no significant difference between males and females regarding laboratory changes 6 months after intervention. Laboratory improvements were significantly lowest among cases with stage 4, followed by stage 3, and the highest among cases with stage 2. There was a decrease in all anemia clinical manifestations after 6 months of lactoferrin administration; the differences were significant only in easy fatigability, constipation, and gastrointestinal upset, which were the most frequent adverse effects. Conclusion Oral lactoferrin was found to be effective in treating iron-deficiency anemia regarding blood Hb, blood RBCs, serum iron, serum ferritin, and TIBC in association with erythropoietin therapy. The effect declines with the progression of CKD.

Keywords: chronic kidney disease, iron supplementation, oral lactoferrin

How to cite this article:
El-Farsy MS, El-Hakim IZ, Al-Arian RA. Role of oral lactoferrin as a source of iron supplementation in correction of anemia in pediatric patients with chronic kidney disease stages 2–4. J Egypt Soc Nephrol Transplant 2022;22:193-9

How to cite this URL:
El-Farsy MS, El-Hakim IZ, Al-Arian RA. Role of oral lactoferrin as a source of iron supplementation in correction of anemia in pediatric patients with chronic kidney disease stages 2–4. J Egypt Soc Nephrol Transplant [serial online] 2022 [cited 2023 Jun 8];22:193-9. Available from: http://www.jesnt.eg.net/text.asp?2022/22/4/193/356687

Introduction

Iron deficiency and iron-deficiency anemia are the most common iron disorders worldwide. When iron requirement is higher than that is absorbed, a negative iron balance occurs and iron stores decrease [1].

Recently, it has been shown that there is significant decrease of total serum iron and serum ferritin combined with increase of serum interleukin 6, which have been observed in hemodialysis patients treated with oral ferrous sulfate [2]. These results support the possibility that iron supplemented via ferrous sulfate is not exported from cells to circulation but is accumulated inside host cells, resulting in inflammatory conditions.

The pathophysiology of iron homeostasis disorders such as iron deficiency in blood has remained enigmatic. Yet, this is an important contribution to the understanding of systemic iron homeostasis and attempts to develop better therapy strategies for treating iron deficiency and iron-deficiency anemia, while oral ferrous sulfate is still widely used [3].

Notwithstanding its known adverse effects, few papers have explored the underestimated problems with this therapy [4]. Ferrous sulfate often fails to restore iron homeostasis in patients experiencing iron-deficiency anemia and frequently causes many adverse effects such as gastrointestinal discomfort, nausea, vomiting, diarrhea, and constipation [5].

Lactoferrin is a non-heme iron-binding protein that is structurally and chemically similar to serum transferrin, whose function is to transport iron into blood serum. This glycoprotein is produced by mucosal epithelial cells and found in mucosal secretions such as saliva, tears, nasal, bronchial secretions, and most highly in milk, making it the second abundant protein after casein [6].

Lactoferrin has proved to have 300 times higher affinity to iron as compared with serum transferrin and an ability to retain iron over a broad pH range. Moreover, it influenced iron homeostasis by increasing iron export from gastrointestinal tract and enhanced iron storage in ferritin [4].

Bovine lactoferrin represents an attractive and promising alternative to ferrous sulfate. Studies have shown that oral administration of bovine lactoferrin, 30% iron saturated, significantly improved hematological markers, including number of red blood cells (RBCs), hemoglobin (Hb), total serum iron, and serum ferritin concentrations compared with those treated with ferrous sulfate [4].

To evaluate this finding, we designed this follow-up case study. This is the first study to evaluate the effect of oral bovine lactoferrin on patients with iron deficiency with chronic kidney disease (CKD) stages 2–4.

Patients and methods

This follow-up cohort clinical study was conducted on children with CKD in conservative clinic, Pediatric Nephrology Unit, Children’s Hospital, Ain Shams University. It included 45 pediatric patients with CKD stages from 2 to 4 for 6 months without a control group. According to KDIGO (Kidney Disease Improving Global Outcomes) 2012 [7] classification of CKD based on glomerular filtration rate (GFR), CKD was categorized into the following stages: stage 2 with GFR between 60 and 89 ml/min/1.73 m², stage 3 with GFR between 30 and 59 ml/min/1.73 m², and stage 4 with GFR between 15 and 29 ml/min/1.73 m².

Ethics approval and consent to participate: This study protocol was approved and deemed sufficient by the Ethical Committee of Faculty of Medicine, Ain Shams University, and informed and written consent was obtained in every case from the patients’ legal guardians. The study conforms to the provisions of the Declaration of Helsinki. Approval number is not available.

All the included patients in the study were on erythropoietin therapy ranging from 150 to 300 IU/kg once per week. Oral iron was stopped without a washout period almost immediately before starting oral lactoferrin according to Skikne et al. [8], which stipulated a washout period in those who received intravenous iron only. This study was carried out from the first of July 2018 to the end of December 2018.

Laboratory evaluations, which includes blood Hb level, serum iron, serum ferritin, and total iron-binding capacity (TIBC), were done for the patients at baseline and 6 months after administration of bovine lactoferrin for 6 months. Oral bovine lactoferrin (100 mg of bovine lactoferrin over a quarter cup of water) was given twice daily for 6 months with no relation to meals [4,9]. All of the patients were compliant to treatment. During the treatment period, Hb level was assayed monthly. After 6-month period of the study, Hb level, TIBC, serum iron, and serum ferritin were assayed again.

According to KDIGO [7] definition of anemia for children aged 0.5–5 years is blood Hb less than 11 g/dl, for 5–12 years is blood Hb less than 11.5 g/dl, for 12–15 years is blood Hb less than 12 g/dl, and for more than 15 years old is blood Hb less than 12 g/dl in females and less than 13 g/dl in males.

The diagnosis of absolute iron deficiency is usually based on low serum ferritin concentrations (<20–30 µg/l) that reflect low body iron stores [10]. In patients with CKD, because of the presence of inflammation, threshold values indicating iron deficiency are generally considered to be higher than in those without kidney disease. Serum ferritin levels of 100 or 200 µg/l are frequently cited as a cutoff value in non-dialysis CKD and dialysis patients, respectively [7].

If BMI is equal to or greater than the fifth percentile and less than 85th percentile for age, sex, and height, it is considered a healthy weight [11].

Sample size

This is a pilot study which included 45 pediatric patients with various stages of CKD (stages from 2 to 4).

All the included patients were subjected to the following clinical parameters: detailed history with stress on demographic data (age, sex, and socioeconomic status), etiology of CKD, and compliance to treatment; general examination with stress on clinical signs of CKD; and estimated GFR as estimated from the constant (k), plasma creatinine concentration (PCr) (in mg/dl), and body length (L) (in cm) according to the Schwartz formula, as follows (National Kidney Foundation, 2002) [12]:

The value of k is different at different ages:

k=0.55 for those aged 2–12 years in children and adolescent girls.

k=0.7 years in adolescent boys.

All of the following laboratory investigations were done for the patients: complete blood count (for the Hb and RBC volume) was done using blood withdrawn in an EDTA tube using Coulter LH 780 analyzer, which provided an automated reticulocyte analysis and enumeration of nucleated red blood as well as an automated method for enumeration of RBCs and white blood cells in body fluids. Overall, 5 ml of blood was drawn from each patient and then centrifugation of the sample was done for 15 min in a horizontal rotator set at 180–220 rpm at room temperature, and separation of the serum from the cells was done for the following: serum iron was done using Beckman coulter Au 480 by using TPTZ [2, 4, 6-Tri-(2-pyridyl)-5-triazine] as the chromogen. In an acid medium, transferrin-bound iron dissociates into free ferric ions and apo-transferrin. Hydrochloric acid and sodium ascorbate reduce the ferric ions to the ferrous state. The ferrous ions then react with TPTZ to form a blue colored complex, which can be measured bichromatically at 600/800 nm. The increase in absorbance is directly proportional to the amount of transferrin-bound iron present.

Statistical analysis

The collected data were revised, coded, tabulated, and introduced to a PC using the Statistical Package for the Social Sciences (SPSS 15.0.1 for Windows, 2001; SPSS Inc., Chicago, Illinois, USA). Data were presented, and suitable analysis was done according to the type of data obtained for each parameter.

(1) Descriptive statistics were as follows:
- (a) Mean and SD for quantitative parametric data.
- (b) Median and interquartile range for quantitative non-parametric data.
- (c) Frequency and percentage were used for presenting qualitative data.
(2) Analytical statistics were as follows:
- (a) Student t test was used to assess the statistical significance of the difference between the study groups means.
- (b) χ² test was used to examine the relationship between two qualitative variables. P value more than 0.05 was considered to be statistically significant.

Correlation analysis (using the Pearson method): it was done to assess the strength of association between two quantitative variables. The correlation coefficient denoted symbolically as r defines the strength (magnitude) and direction (positive or negative) of the linear relationship between two variables.

(1) r=0–0.19 is regarded as very weak correlation.

(2) r=0.2–0.39 as a weak correlation.

(3) r=0.40–0.59 as a moderate correlation.

(4) r=0.6–0.79 as a strong correlation.

(5) r=0.8–1 as a very strong correlation.

Results

The study included 45 patients with age ranged from 2 to 12 years, and BMI ranged from -1.71 to 1.11. Males represented 24 (53.3%) and females 21 (46.7%). A total of 26 (57.8%) patients had CKD owing to congenital causes: posterior urethral valve, vesicoureteral reflux, multicystic dysplastic kidney, and single functioning kidney and 19 (42.2%) due to non-congenital causes: systemic lupus erythematosus, hemolytic uremic syndrome, acute tubular necrosis. Overall, 25 (55.6%) patients were stage 2, 14 (31.1%) were stage 3, and six (13.3%) were stage 4 ([Table 1]).

Table 1: Demographic and clinical characteristics of the studied cases

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[Table 2] shows that serum iron significantly increased 6 months after administration of lactoferrin.

Table 2: Serum iron (µmol/l) among the studied cases

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[Table 3] shows that blood Hb significantly increased beginning from first month after intervention: after 2 months, three of 45 patients had reached above the target Hb level 12 g/dl; after 3 months, seven of 45 patients had reached above the target Hb level; after 4 months, nine of 45 patients had reached above the target Hb level; after 5 months, 13 of 45 patients had reached above the target level; after 6 months, 15 of 45 had reached above the target level. Erythropoietin dose was decreased to half and then stopped when the raised levels were maintained. The second part of the table shows the difference in Hb levels between before and after every month of lactoferrin administration: difference in Hb levels between before and after first month of lactoferrin administration was 1.1 ± 0.5 g/dl, after second month of administration was 2.2 ± 0.8 g/dl, after third month was 2.9 ± 1.1 g/dl, after fourth month was 3.3 ± 1.3 g/dl, after fifth month was 3.6 ± 1.3 g/dl, and after sixth month was 3.9 ± 1.4 g/dl, and all of them showed a highly significant difference in Hb levels.

Table 3: Blood hemoglobin (g/dl) among the studied cases

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[Table 4] shows that blood RBC significantly increased beginning from first month after administration of lactoferrin. The second part of the table shows a difference in RBC number between before and after every month of lactoferrin administration: difference of RBC number between before and after first month of lactoferrin administration was 0.3 ± 0.1 × 10¹²/l, after second month of administration was 0.5 ± 0.2 × 10¹²/l, after third month was 0.6 ± 0.3 × 10¹²/l, after fourth month was 0.7 ± 0.4 × 10¹²/l, after fifth month was 0.8 ± 0.4 × 10¹²/l, and after sixth month was 0.9 ± 0.5 × 10¹²/l, and from the second month, it shows a highly significant difference in RBC number.

Table 4: Blood red blood cell (×10¹²/l) among the studied cases

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[Table 5] shows that laboratory improvements were significantly lower among cases with stage 4, followed by stage 3, with highest among cases with stage 2.

Table 5: Comparison between chronic kidney disease stages regarding laboratory changes 6 months after intervention to baseline values

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[Table 6] shows the adverse effects of lactoferrin administration among the studied cases. Constipation and gastrointestinal tract upset were the most frequent adverse effects. All anemia clinical manifestations decreased 6 months after treatment. The difference was significant only in easy fatigability, which is assessed by the fatigue assessment scale in children [13].

Table 6: Adverse effects of lactoferrin administration among the studied cases

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Discussion

Bovine lactoferrin represents an attractive and promising alternative to ferrous sulfate. Studies have shown that oral administration of bovine lactoferrin, 30% iron saturated, significantly improved hematological markers, including number of RBCs, Hb, total serum iron, serum ferritin concentrations compared with those treated with ferrous sulfate [4].

Provenzano et al. [2] revealed that a significant decrease in serum iron and serum ferritin had been observed in hemodialysis patients treated with oral ferrous sulfate. These results strongly support the possibility that iron supplemented via ferrous sulfate is not exported from cells to circulation, but it is accumulated inside host cells, resulting in inflammatory conditions, which highlighted the consideration of new approaches in treating iron-deficiency anemia.

Presence of lactoferrin in tissue and secretions avoids iron precipitation, microbial growth, and formation of reactive oxygen species [14].

During the comparison of the study results with other studies, it was found that this study is a pilot study, and we are the first to perform a study regarding the effect of oral lactoferrin on pediatric patients with iron-deficiency anemia who have CKD stages from 2 to 4. So, there was no reference in pediatric patients. The available studies were mainly on adults.

Regarding the age of the pediatric patients with CKD who underwent this study, it ranged from 2 to 12 years, with a mean age of 7.5 ± 2.6 years. However, the difference was not statistically significant between the male and female groups. Regarding sex, the current study revealed that 53.3% are males and 46.7% are females, with no statistically significant difference between both males and females. Regarding age and sex, the results are in line with the study by Harambat et al. [15] where the percentages of children with estimated GFR less than 90 and less than 75 ml/min/1.73 m² were consistently highest in the 5- to 7-year age group, which draws our attention to the younger age groups having an increased risk of CKD owing to congenital abnormalities of kidney and urinary tract.

Regarding serum iron measured in the pediatric patients with CKD in this study, the range before lactoferrin administration was 3–16 µmol/l and after 6 months of lactoferrin administration, it ranged from 12 to 31 µmol/l, which shows that serum iron significantly increased 6 months after intervention. Sehgal et al. [16] studied serum iron levels in comparison between normal and patients with CKD and revealed significant lower levels of iron in patients with CKD.

Regarding serum ferritin measured, the range before lactoferrin administration was 10.0–26.0 µmol/l and after 6 months of lactoferrin administration, it ranged from 19.0 to 113.0 µmol/l, showing that serum ferritin significantly increased 6 months after intervention. Bárány and Müller [17] studied iron profile in patients with CKD before and after iv iron administration and showed that serum ferritin before treatment was 235.9 µg/l and significantly increased after intravenous iron administration. Agarwal et al. [18] studied the difference in iron profile parameters between intravenous and oral iron and showed serum ferritin levels were higher with intravenous iron treatment, with a mean difference (MD) of 229.01 µg/l.

Serum TIBC measured among the studied cases before treatment ranged from 56.0 to 95.0 µmol/l and after treatment ranged from 45.0 to 76.0 µmol/l, showing serum TIBC significantly decreased 6 months after intervention. The study by Bárány and Müller [17] showed that transferrin saturation before treatment was 13.5% and increased significantly with iron treatment. Transferrin saturation in the study by Agarwal et al. [18] was significantly higher with intravenous therapy than oral therapy, with a MD of 6.89%.

Regarding the range of Hb before treatment in the studied cases, it was 7.1–12.2 g/dl, and it was checked every month till it ranged from 11.6 to 14.7 g/dl 6 months after treatment, showing blood Hb significantly increased beginning from first month after intervention. Regarding the cases in which Hb level reached above the target level, erythropoietin dose was decreased to half and then stopped when the raised levels were maintained. Blood RBC among the studied cases before treatment ranged from 2.8 to 4.8 × 10¹²/l, and it was checked every month till it reached 3.8 to 5.1 × 10¹²/l after 6 months of treatment, showing blood RBC significantly increased beginning from second month after intervention.

Bárány and Müller [17] showed that mean Hb increased from 10.16 ± 1.32 to 11.96 ± 1.52 g/dl, showing a significant increase after treatment, where 26 of 46 patients reached the target Hb of 12 g/dl. Ten (21.3%) patients had an increase of 0.1–0.9 g/dl, nine (19.1%) patients had an increase of 1–1.9 g/dl, and 23 (48.9%) patients had an increase of more than or equal to 2 g/dl.

According to Agarwal et al. [18], the MD in blood Hb was 0.45 g/dl in non-dialysis patients. The number of patients who reached target Hb or increased Hb by at least 1 g/dl were represented by patients receiving intravenous iron than oral iron.

By comparing intravenous iron with oral iron (22 studies, 1862 patients: MD 0.90 g/dl) in all patients, and in the subgroups of dialysis patients (13 studies, 828 patients: MD 1.16 g/dl), and non-dialysis patients (eight studies, 1020 patients: MD 0.45 g/dl), there were high levels of heterogeneity in all analyses (58–97%), which persisted when a fixed-effect model was used for analysis. Excluding a study of 26 months of treatment and MD 4.92 g/dl [19] did not reduce heterogeneity. The numbers of patients reaching target Hb or increasing Hb by at least 1 g/dl were reported in 10 studies. Target Hb or an increase in Hb by 1 g/dl or more was achieved by patients receiving intravenous iron compared with oral iron. Ten studies showed that comparison between CKD stages regarding laboratory changes 6 months after intervention showed that laboratory improvements were significantly lower among cases with stage 4, followed by stage 3, with the highest among cases with stage 2.

Bowling et al. [20] studied the prevalence of anemia in CKD stages and revealed the prevalence was higher if the stages progressed, ranging from 12.2% in stage 2, 17.4% in stage 3 to 50.3% in stage 4.

When studying the clinical manifestations of anemia in the studied cases, it was found that all anemia clinical manifestations decreased 6 months after treatment; the differences were significant only in easy fatigability. Regarding adverse effects of the drug administrated to the studied cases, constipation and gastrointestinal tract upset were the most frequent adverse effects. There were no relevant studies on the adverse effects of oral lactoferrin in patients with CKD.

Conclusion

Oral lactoferrin was found to be effective in treating iron-deficiency anemia regarding blood Hb, blood RBCs, serum iron, serum ferritin, and TIBC in association with erythropoietin therapy in pediatric patients with CKD stages 2 to 4. The effect declines with the progression of CKD.

Limitations

There are some limitations in our study. First, the duration of the study was limited to 6 months only. Second, there was no association of CKD with malnutrition and more susceptibility to infections. Third, maintenance of compliance was not assessed. Fourth, our study lacked measurement of hepcidin and interleukin 6.

Recommendations

We recommend the following: (a) treatment of pediatric patients with iron-deficient CKD with oral bovine lactoferrin as required; (b) another study assessing treatment with both oral iron with oral lactoferrin to increase its iron concentration; (c) follow-up of pediatric patients with CKD with iron profile for longer periods; (d) more future studies on the effect of lactoferrin on iron-deficiency anemia; (e) more evaluations of the association between lactoferrin and interleukin 6, which was found to have a positive correlation with infection and inflammation, which aggravate anemia in pediatric patients with CKD.

Acknowledgements

Authors would like to thank all patients and their family members for their valuable contributions to the study.

Financial support and sponsorship

Nil

Conflicts of interest

There are no conflicts of interest.

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