Investigation of iron's neurotoxicity during cerebral maturation in the neonatal rat model of haemolysis.

INTRODUCTION: Haemolytic disease of newborns due to rhesus and AB0 incompatibility is encountered frequently in neonatal clinics and may lead to severe haemolysis. In this study, it is suggested that important amounts of iron released with haemolysis may have a toxic effect on the brain parenchymal tissue, and the severity of the toxic effect can be correlated with the maturation of the brain barrier systems. To demonstrate the accumulation and the neuro-toxic effects of free iron (Fe) in the brain an experimental haemolysis model with various maturation phases was performed. MATERIAL AND METHODS: The study was composed of 48 Wistar rats with the following ages: five days old (Group A), 10 days old (Group B), and 19 days old (Group C). Each group was divided into three experimental subgroups and three control groups. Experimental groups were treated with intraperitoneal 75 mg/kg/day phenyl hydrazine hydrochloride for haemolysis. RESULTS: We demonstrated that the blood brain barrier (BBB) is permeable in five-day-old newborn rats and is mature in 10- and 19-day-old rats. Iron staining and neuronal damage were detected in group A and group B rats. No damage was detected in the brain tissue of group C animals. The presence of iron staining and neuronal damage in group B with mature BBB may suggest the existence of other incomplete barrier systems different from BBB that lead to iron accumulation in the brain. CONCLUSIONS: Blood brain barrier has a partial role in Fe transport, and the alternative barrier systems may also be involved. It could be supposed that after maturation of all barrier systems, excessive Fe penetration to the brain cannot occur. Our findings showed that the toxic amounts of iron may penetrate into the brain parenchyma of newborns despite the BBB preservation and cause neuronal damage in newborns, but the mature brain is not affected by the same magnitude blood levels.

The value of serum immunoglobulin free light chain assessment in patients with monoclonal gammopathies and acute renal failure.

OBJECTIVE: Immunoglobulin free light chain (FLC) abnormalities are common in patients with monoclonal gammopathies and the kidneys are the most affected organs. Immunoassays that provide quantitative measurement of FLC in serum indicate monoclonal FLC production based on the presence of an abnormal FLC kappa:lambda (κ:λ) ratio. The aim of this study was to assess the utility of serum FLC measurement as a diagnostic tool for detecting plasma cell dyscrasias in comparison to standard assays, and to ascertain its sensitivity and specificity in patients with acute renal failure (ARF). MATERIAL AND METHODS: Sera from 82 patients with ARF were assessed using serum protein electrophoresis (SPE), serum immunofixation electrophoresis (SIFE), and FLC measurement. The sensitivity and specificity of the FLC ratio in identifying which ARF patients had multiple myeloma (MM) was compared to those of SPE and SIFE. RESULTS: Among the 82 patients with ARF, 7 were diagnosed as MM using SPE, SIFE, and bone marrow biopsy techniques. In total, 8 patients did not have a FLC κ:λ ratio that was within the published reference range (0:26-1:65); the FLC κ:λ ratio based on FLC measurement had a specificity of 96% and sensitivity of 71%, and positive and negative predictive values of 62.9% and 97.3%, respectively, for the diagnosis of MM. CONCLUSION: The sensitivity and specificity of the FLC κ:λ ratio for diagnosing MM in patients that presented with ARF were lower than those of SPE and SIFE. To further delineate the utility of the FLC κ:λ ratio additional prospective, well-designed large-scale studies are needed. CONFLICT OF INTEREST: None declared.