At the start, all patients with CKD on different RRT who attended or were referred to the clinic between 1st January 2021 and 31st December 2025 were screened for IO and its subsequent hepatopathy (liver hemosiderosis and cirrhosis). Diagnosis of IO was considered if high serum levels of (a) transferrin saturation% (>40%) and (b) ferritin (>1110 μg/L) were present in patients who had not received intravenous iron for >12 weeks [14][15]. Moreover, it was confirmed by high CT density (>70 Hounsfield units) and grade 6 bone marrow iron stores [16].

Diagnosis of liver disease was established by abnormal liver on: (a) serum tests that showed high transaminases, alkaline phosphatase, and gamma-glutamyl transferase, and/or (b) abdominopelvic sonography viz. abnormal liver size/shape, enlarged spleen, and ascites. After exclusion of other liver-disease etiologies (Vida infer); liver biopsy was done in the selected patients to assess the etiology of their liver disease, acquired hemosiderosis, and cirrhosis [17]. Endocrine tests included: (a) pancreas: hemoglobin A1c, C-peptide, insulin, pancreatic elastase, amylase, and lipase, (b) thyroid viz. TSH with free T3 and T4, (c) early morning serum cortisol and ACTH for adrenal gland, (d) pituitary: IGF, FSH, LH, ACTH, prolactin, and copeptin, and (d) gonads: sex hormones (testosterone in males, estradiol and progesterone in females). Dynamic tests included: (a) gonadotropin-releasing hormone (GnRH), (b) synthetic adrenocorticotrophic hormone 1 - 24 (ACTH) stimulation tests, and modified glucose tolerance test (MOGTT). Dynamic endocrine testing was done by blood sample collected prior to the scheduled dialysis session, followed by intravenous injection of 100 µg of GnRH and 250 µg of ACTH. Blood sample collection was done at time 0, 30 minutes, and 60 minutes. MOGTT was performed 1 week after completion of GnRH and ACTH stimulation tests. Patients were given 1 g/kg glucose syrup and blood samples were collected at start, after 1 and 2 hours, for assessment of glucose and insulin. The response to stimulatory tests was considered adequate if a minimum of: (a) 100% increment in LH was achieved after 2 hours of GnRH injection, (b) 200% increase in plasma cortisol levels after 2 hours of ACTH injection, and (c) 100% increase in free insulin after 2 hours of oral glucose ingestion. Moreover, echocardiogram was used to assess the myocardium.

To assess for IO-hepatic disease, patients were excluded if they had clinical evidence, laboratory tests, serological markers, genetic mutations, and radiological images indicating alcohol abuse, autoimmune diseases, chronic infection, malignancy, were on immunosuppressive therapy, as well as those with defective erythropoiesis viz. hemochromatosis, hemoglobinopathies, dysplastic bone marrow (myelofibrosis, myelodysplasia, multiple myeloma), amyloidosis, malignancy, osteitis fibrosa cystica, and aluminum overload (serum level > 60 µg/L) [18]-[20]. Patients with previous non-IO endocrinopathy and heart disease were excluded from such assessment.

In patients with IO, oral and intravenous iron were avoided, and periodic phlebotomy was performed. The latter consisted of the removal of 450 ml of the patient’s blood per session weekly for 1 month, followed by twice monthly until TS% & SF levels were normalized. Deficiencies in vitamin B12 and folates were corrected periodically, and subcutaneous erythropoietin (Darbepoetin alpha) was used to maintain an adequate hemoglobin level (110 - 120 g/L) [21][22].

Patients were assessed clinically as well as by laboratory testing (complete blood count, TS%, SF, liver function) every week for 1 month, then every 2 weeks for the subsequent 2 months. Radiological tests, viz. abdominal ultrasound (to assess for liver, spleen, and ascites) and CT (to assess for liver CT density), were performed at the start and after 3 months. Upper GI endoscopy was done when indicated.

SPSS statistical package version 25 was used for data entry and processing. The p-value < 0.05 was used as the cut-off level for significance. Since all variables were normally distributed, they were expressed as mean + SD and compared using Student’s t-test. Comparison of changes with time, following therapy, and between groups was done using the t-test for two dependent means and for two independent ones.

In the 23 patients with IO and liver disease, liver biopsy showed diffuse: (a) iron deposition in the sinusoidal Kupffer cells (severe hemosiderosis) in 6 patients (Figure 1), and (b) iron-loaded hepatocytes with a variable degree of cirrhosis in the other 17 patients (Figure 2).

(a) normal histology on H&E stain (b) diffuse amorphous iron-containing clumps of hemosiderin (blue deposits) in sinusoidal Kupffer cells (arrow) on Perls’ Prussian blue stain.

Figure 1. Liver biopsy micrographs of patients with renal iron overload.

(a) bridging fibrosis (Arrow) on H&E stain (b) diffuse and mixed (sinusoidal Kupffer cells and hepatocytes) amorphous iron-containing clumps of hemosiderin (blue deposits) (Arrow) on Perls’ Prussian blue stain.

Figure 2.Liver biopsy micrographs of patients with iron overload in renal disease.

Those patients were classified into three groups, viz. without hepatic disease, with acquired hemosiderosis, and with cirrhosis. The demographic data of the three patient groups were compared with regard to duration of renal disease, duration of IO treatment, clinical cirrhosis, and response to therapy (Table 1). Significantly longer duration of RRT as well as higher serum TS%, ferritin, and CT-density were observed in those with cirrhosis compared to those with acquired hemosiderosis, followed by those without liver disease. The latter two groups had a higher female predominance compared to those with cirrhosis. Overt cirrhotic disease, viz. clinical, laboratory indices, and/or radiological, was evident in 12 of the 17 cirrhotic patients and in none of the other two groups. As seen in Table 2, patients with biopsy-proven liver disease: (a) higher serum TS%, ferritin, and CT-density were most evident in patients on MPD, and (b) higher response to therapy (holding iron supplementation and phlebotomy) was more effective in patients on MHD.

Endocrine testing showed normal sex hormones in male patients, indicating an intact pituitary-gonadal axis. In female patients, 2 KTx patients were < 40 and had adequate sex hormones and an intact GnRH stimulation test. On the other hand, low levels of sex hormones with high gonadotrophins indicated primary gonadal failure, except for 2 MPD patients with low gonadotrophins, indicating a diseased anterior lobe of the anterior pituitary gland that failed to increase following GnRH stimulation tests. Moreover, they had low IGF and inappropriately low TSH in the face of low free T4, indicating pituitary disease. Copeptin levels were normal in all patients, indicating an intact posterior lobe of the pituitary gland. The ACTH stimulation test produced an adequate increment in plasma cortisol, indicating intact adrenal function. For assessment of endocrine function, 6 patients with long-standing diabetes mellitus were excluded from assessment of beta-cell function yet had pancreatic elastase, amylase, and lipase, indicating intact stromal exocrine function. The remaining patients had normal endocrine and exocrine function on testing.

Seven patients had a history of ischemic heart disease, and localized wall motion abnormalities were excluded from the study, as well as 2 patients with aortic stenosis. In the remaining patients, 2 patients on MPD showed features of dilated cardiomyopathy that were slowly progressive on follow-up and without history or laboratory indicators of viral myocarditis.

Treatment was tolerated in all patients. It led to significant and rapid laboratory improvement in all parameters (TS%, SF, BM iron stores, and CT density) within 3 months (Table 1 and Table 2, Figure 3). Moreover, over a period of 42 ± 11 months, no new cases of hepatic, endocrine, or cardiac disease had evolved. None of the patients with (a) hemosiderosis had developed clinical, laboratory, or radiological evidence of cirrhosis, (b) overt and non-overt cirrhotic disease had manifested disease progression, and (c) endocrine or cardiac disease had manifested disease progression.

Table 1. Demographic characteristics and response to phlebotomy in iron-overloaded renal patients on different RRT.

Abbreviations: RRT; renal replacement therapy, RD; renal disease, F; female, M; male, SF, CT; computed tomography; RRT: renal replacement therapy, CKT: conservative kidney therapy, MHD: maintenance haemodialysis, MPD: maintenance peritoneal dialysis, KTx: kidney transplantation. Data expressed as mean ± standard deviation with NS; not significant, (*) significant difference.

Table 2.Demographic characteristics and response to phlebotomy in iron overload patients with hepatic disease on different renal replacement therapies (RRT).

Abbreviations: RD; renal disease, F; female, M; male, SF, CT; computerized tomography, Rx: phlebotomy treatment, RRT: renal replacement therapy, CKT; conservative kidney therapy, MHD; maintenance haemodialysis, MPD; maintenance peritoneal dialysis, KTx; kidney transplantation. Data expressed as mean ± standard deviation with NS: statistically not significant, (*) significant.

Figure 3. CT scan of the liver in a renal patient with iron overload, showing a decrease in hepatic CT density from 86 HU at the start (A) to 75 HU after repeated phlebotomy (B).