A Case of Nephrotic Syndrome in an Infant: Diagnostic and Therapeutic Challenges

Tristan Khoury^*
*Correspondence: Tristan Khoury, Department of Pediatrics, Germany, Email:

Introduction

Nephrotic Syndrome (NS) is a clinical condition characterized by heavy proteinuria, hypoalbuminemia, hyperlipidemia, and edema. While nephrotic syndrome is relatively common in pediatric populations, it is much rarer in infants, especially those under one year of age. In this age group, the condition presents unique diagnostic and therapeutic challenges due to the complexity of distinguishing it from other causes of edema and proteinuria, the difficulty in obtaining accurate urine samples, and the lack of definitive markers for diagnosis in very young children. In infants, nephrotic syndrome can present as either primary (idiopathic) or secondary to underlying systemic conditions such as infections, autoimmune diseases, or metabolic disorders. The most common cause of nephrotic syndrome in infants is Minimal Change Disease (MCD), a form of glomerulopathy that is characterized by normal appearing glomeruli on light microscopy but significant podocyte dysfunction. However, other causes, including congenital nephrotic syndrome or secondary causes such as systemic infections, can also present in this age group, complicating the diagnostic process. This case report describes a rare instance of nephrotic syndrome in an infant, focusing on the diagnostic approach and therapeutic challenges associated with managing such a young patient. It underscores the importance of considering nephrotic syndrome in infants who present with nonspecific symptoms like unexplained edema or growth failure, and highlights the complexities involved in confirming the diagnosis, identifying the underlying cause, and initiating appropriate treatment. The case also discusses the unique therapeutic challenges in managing infants with nephrotic syndrome, including the delicate balance of managing edema, preventing infection, and addressing the risk of long-term kidney damage. Through this case, we aim to raise awareness about the presentation of nephrotic syndrome in infancy and provide insights into optimizing care for this vulnerable patient population [1].

Description

Nephrotic Syndrome (NS) is a condition characterized by a group of clinical features that include significant proteinuria, low serum albumin levels, edema, and hyperlipidemia. While nephrotic syndrome is a relatively wellrecognized condition in older children and adults, its occurrence in infants is quite rare and presents unique diagnostic and therapeutic challenges. In infants, nephrotic syndrome can be difficult to distinguish from other causes of edema, such as malnutrition, infections, or heart failure. Moreover, the delicate physiology of infants, along with the difficulty of obtaining accurate urine samples in this age group, adds layers of complexity to both the diagnosis and treatment of this condition. The causes of nephrotic syndrome in infants can be broadly categorized into primary and secondary causes. Primary nephrotic syndrome in infants is most often caused by Minimal Change Disease (MCD), a condition in which the kidneys appear normal under a microscope, but there is significant dysfunction at the level of the podocytes, the cells responsible for

the selective filtration of proteins. MCD is thought to result from an immunemediated process, though the exact mechanisms remain unclear. Secondary nephrotic syndrome can be caused by a variety of underlying conditions, such as congenital infections, autoimmune diseases, or metabolic disorders. In infants, the possibility of congenital nephrotic syndrome, a genetic disorder that results in nephrotic syndrome within the first few months of life, must also be considered [2]. Given that nephrotic syndrome in infants can present with nonspecific symptoms like swelling, poor weight gain, irritability, or lethargy, it can easily be misdiagnosed or mistaken for more common conditions, such as allergic reactions or gastrointestinal issues. The initial presentation may also be subtle, with edema being the most prominent symptom, making it harder to identify the underlying cause. The diagnosis of nephrotic syndrome in infants typically involves a combination of clinical observation, laboratory tests, and imaging studies. Urinary protein excretion is the cornerstone of diagnosis, with a 24- hour urine protein measurement or a urine protein-to-creatinine ratio being used to quantify proteinuria. However, obtaining accurate urine samples in infants can be challenging, and the measurement of proteinuria can sometimes be complicated by the presence of other conditions like urinary tract infections or dehydration. In some cases, kidney biopsy may be necessary to confirm the diagnosis and to differentiate between the various causes of nephrotic syndrome, though this is usually reserved for more severe or complicated cases [3]. Treatment of nephrotic syndrome in infants involves addressing both the immediate symptoms and the underlying cause. The first-line treatment for primary nephrotic syndrome, particularly minimal change disease, is the use of corticosteroids. Steroids are effective in most cases of nephrotic syndrome in infants, leading to a rapid reduction in proteinuria and improvement in edema. However, the use of steroids in infants comes with its own set of challenges, including the risk of side effects such as immunosuppression, growth retardation, and gastrointestinal disturbances. In some cases, infants with steroid-resistant nephrotic syndrome may require other immunosuppressive agents or biologic therapies, though these are often less studied in this very young population and may not always be appropriate due to the potential for long-term side effects. In addition to pharmacological treatment, the management of edema and fluid balance is critical in the care of infants with nephrotic syndrome. Edema can lead to respiratory distress, poor feeding, and developmental delays, and may also increase the risk of infections due to compromised skin integrity. Infants with nephrotic syndrome often require close monitoring of fluid status and may need diuretics to manage excess fluid. However, the use of diuretics must be carefully controlled to avoid dehydration and electrolyte imbalances, as the infant’s renal and circulatory systems are still immature and more prone to complications [4].

Nutrition is another crucial aspect of managing nephrotic syndrome in infants. These infants often experience protein loss through the urine, leading to hypoalbuminemia and a risk of malnutrition. Parenteral nutrition may be required in some cases to ensure adequate caloric and protein intake, particularly if the infant is unable to feed adequately due to swelling or lethargy. Balancing adequate nutrition to support growth while managing edema and minimizing the risk of infection presents a significant challenge. Secondary nephrotic syndrome in infants requires additional diagnostic workup to identify and treat the underlying condition. In cases where infections, metabolic disorders, or systemic diseases are suspected, targeted treatments such as antibiotics, antivirals, or immune-modulating therapies may be required. Identifying and addressing any contributing factors is essential for the effective management of nephrotic syndrome, as secondary causes may influence

the long-term prognosis of the condition. Despite the challenges in diagnosis and treatment, the prognosis for infants with nephrotic syndrome is generally favourable when appropriate management is provided. Most infants with primary nephrotic syndrome, especially those with minimal change disease, respond well to steroid therapy and have a good long-term outcome. However, in cases of steroid-resistant nephrotic syndrome or secondary nephrotic syndrome due to underlying conditions, the prognosis can be more variable and may require more aggressive and long-term management. Monitoring for complications, such as infections, thrombosis, or progressive kidney damage, is essential for ensuring optimal outcomes [5].

Conclusion

This case report aims to shed light on the diagnostic and therapeutic challenges involved in managing nephrotic syndrome in an infant, emphasizing the need for careful consideration of this condition in the differential diagnosis of infants presenting with edema and poor feeding. While nephrotic syndrome in infants is rare, it should not be overlooked, as early identification and appropriate treatment can significantly improve the quality of life and long-term health outcomes for these vulnerable patients. Through this case, we hope to raise awareness about the complexities involved in diagnosing and treating nephrotic syndrome in infants and provide valuable insights for clinicians facing similar cases.

References

1. Bhatt, Girish Chandra, Shikha Jain and Rashmi Ranjan Das. "Zinc supplementation as an adjunct to standard therapy in childhood nephrotic syndrome-a systematic review." World J Clin Pediatr 5 (2016): 383.

Google Scholar, Crossref, Indexed at

2. Yanagida-Asanuma, Etsuko, Katsuhiko Asanuma, Kwanghee Kim and Mary Donnelly, H et al. "Synaptopodin protects against proteinuria by disrupting Cdc42: IRSp53: Mena signaling complexes in kidney podocytes." Am J Pathol 171 (2007): 415-427.

Google Scholar, Crossref, Indexed at