ABSTRACT
Aim: To investigate hepcidin as a marker of iron status in chronic kidney disease (CKD) patients (stage 5 vs. stage 3), and to assess its association with iron injection status within the maintenance hemodialysis group.
Materials and Methods: This cross-sectional study compared 69 hemodialysis (stage 5 CKD [G1]) and 19 non-dialysis (stage 3 CKD [G2]) patients, assessing hepcidin, ferritin and hemoglobin. As a part of their standard anemia management, patients requiring iron administration received scheduled injections of ferric carboxymaltose.
Results: Hemodialysis patients (G1) had significantly lower hemoglobin and higher anemia prevalence than non-dialysis patients (G2), while baseline hepcidin and ferritin levels were comparable. Importantly, hepcidin levels were above the normal range in 85,5% and 84,2% of G1 and G2 patients, respectively. Hepcidin
correlated positively with ferritin in both groups (G1: ρ=0,66, p<0,001; G2: ρ=0,87, p<0,001). Within G1, recent iron injections, administered in 24 patients, were significantly associated with higher hepcidin and ferritin, but not hemoglobin, as compared to patients without additional ferric therapy (n=45) (effect size: r=0,09 [by hemoglobin], r=0,80 [by hepcidin] and r=0,58 [by ferritin]).
Conclusions: Significant iron metabolism impairment, marked by high hepcidin and ferritin prevalence, exists in both CKD stages studied. Although hemodialysis patients had lower hemoglobin, baseline hepcidin/ferritin levels were similar between groups. Within the hemodialysis group, recent iron injections were associated with increased hepcidin/ferritin but not hemoglobin. Findings suggest hepcidin may be a crucial indicator of functional iron availability in CKD, potentially offering more insight than ferritin, particularly reflecting acute changes following iron administration in hemodialysis patients.
KEY WORD S: hepcidin, ferritin, chronic kidney disease, hemodialysis

ABSTRACT
Aim: To investigate the relationships of kidney function with clinical and laboratory parameters in multiple myeloma (MM) patients.
Materials and Methods: A cross-sectional study involved 105 MM patients. Data included clinical manifestations and standard laboratory parameters.
Kidney function was assessed via estimated glomerular filtration rate (eGFR), serum creatinine, urea, uric acid (UA), calcium (Ca), and albumin-to-creatinine
ratio (ACR). The markers of MM activity and burden included M-protein, beta-2 microglobulin (β2m), albumin, hemoglobin (Hb), lactate dehydrogenase (LDH)
and platelets (PLT). Rank biserial correlation assessed associations between symptoms and laboratory parameters. Rank-based canonical correlation analysis
(RCCA) explored the multivariate relationship between six kidney function indicators and six MM-related markers.
Results: Common laboratory abnormalities included elevated β2m (90,5 %) and anemia (indicated by low Hb in 52,4 % of patients). Frequent symptoms
included bone pain (71,4 %) and weakness (68,6 %). Symptoms like weakness/breathlessness correlated significantly with (β2m, M-protein) and renal impairment (creatinine, ACR, eGFR). RCCA identified one significant canonical correlation (R1=0,497; p=0,013), linking impaired renal function (characterized by low
eGFR, high ACR, creatinine and urea) with a myeloma profile indicative of disease activity and burden (high β2m, low Hb, low albumin, and high M-protein).
Conclusions: The study confirms a significant multivariate association between a profile of impaired renal function and markers reflecting MM activity, hematopoietic suppression and systemic burden. These findings underscore the multifactorial nature of MM-related kidney injury and highlight the clinical utility
of monitoring key laboratory markers (including eGFR, ACR, creatinine, β2m, Hb and albumin) alongside clinical evaluation for comprehensive assessment
and management of MM patients.
KEY WORDS: multiple myeloma, chronic kidney disease, anemia