Nefrin Mutasyonu Olan Konjenital Nefrotik Sendromlu Hastalarda Nefrektominin Hasta Sağkalım Üzerine Etkisinin Retrospektif Araştırılması
Özet
Congenital nephrotic syndrome is a glomerular disease characterized by protein loss from the kidneys. The onset of the disease occurs in the antenatal period, and patients are diagnosed within the first three months of life. Postnatally, these patients exhibit nephrotic-level proteinuria. Due to protein loss, they experience hypoalbuminemia (serum albumin <2.5 g/dL), edema, and hyperlipidemia. The loss of proteins such as thyroid-binding globulin, antithrombin III, immunoglobulin G, complement C3 and C5, Factor B and D can lead to complications like hypothyroidism, thrombosis, and increased susceptibility to infections. Sepsis is the most common cause of death in these patients.
The management of the disease aims to maintain intravascular volume, manage edema, ensure healthy growth and development, and prevent complications, ultimately leading to kidney transplantation. Continuous protein loss necessitates a high-calorie, protein-rich diet to support normal growth. Continuous albumin replacements may be required to manage edema. Antithrombotic or anticoagulant prophylaxis is recommended for thrombosis prevention. Considering susceptibility to infections, especially to encapsulated bacteria, penicillin G prophylaxis is advised. Due to thyroid-binding globulin loss, initiating levothyroxine is recommended.
The curative treatment for the disease is kidney transplantation, which can be considered for patients with a body weight above 10 kg. While previous studies suggested nephrectomy in patients weighing between 7-10 kg, recent views favor avoiding nephrectomy unless there is a failure to achieve clinical euvolemia or impaired growth.
In our clinic, we observed that patients who underwent nephrectomy had better clinical outcomes. To scientifically test this observation, we conducted a study in collaboration with ten university hospitals' pediatric nephrology departments across Türkiye, collecting and analyzing data from a total of 29 patients with NPHS1 mutation and congenital nephrotic syndrome, some of whom underwent nephrectomy.
Out of the 29 patients, 16 underwent nephrectomy, while 13 were managed conservatively. There was no statistically significant difference in general demographic characteristics between those who underwent nephrectomy and those who did not. However, the group that underwent nephrectomy required more monthly albumin, indicating persistent protein loss. Although serum albumin levels significantly increased after nephrectomy, they did not reach normal levels, likely due to the unilateral nature of most nephrectomies.
Examining renal functions, patients who underwent nephrectomy had a median age of two years for the development of end-stage renal failure and the initiation of renal replacement. Compared to the non-nephrectomy group, the nephrectomy group required renal replacement approximately one year earlier. Growth assessment revealed a significant decline in height "z" scores for the nephrectomy group. Despite a statistically significant decrease in monthly albumin infusion needs, nephrectomy patients had fewer hospitalizations and infections, but an increased incidence of central venous catheter-related thrombosis.
For patients managed conservatively, serum albumin levels showed a statistically significant increase over time, although levels were lower than those in the nephrectomy group. There was no significant change in renal functions, height, or weight "z" scores. While monthly albumin infusion needs decreased over time, there was no statistically significant reduction in hospitalization or infection rates, and no central venous catheter-related thrombosis occurred.
In conclusion, nephrectomy may be considered for congenital nephrotic syndrome patients who experience frequent complications, require frequent hospitalizations, and struggle to maintain euvolemia. Earlier literature suggested nephrectomy for growth-impaired children, but our study indicates that nephrectomy may worsen growth outcomes. Based on our findings, routine nephrectomy for every congenital nephrotic syndrome patient is not recommended. Still, it may be beneficial for selected patients, and its application should be considered based on individual patient characteristics.
