NEUTROPHIL GELATINASE-ASSOCIATED LIPOCALIN (NGAL) AND HUMAN LEUKOCYTE ANTIGEN (HLA) TYPING IN KIDNEY TRANSPLANT

Neutrophil gelatinase-associated lipocalin (NGAL) is a protein released by kidney tubular cells in response to ischemia and can serve as an early indicator of conditions such as immunological rejection, calcineurin inhibitor toxicity, obstructive nephropathy, subclinical tubulitis, or infection. In the management of kidney transplant recipients (KTRs), NGAL is emerging as a significant biomarker. Elevated levels of urinary or serum NGAL shortly after transplantation are predictive of delayed graft function and are associated with diminished graft performance within a year. Furthermore, in KTRs with stable graft function who later develop acute graft dysfunction, high urinary NGAL levels have been linked to an increased risk of graft loss within one year. In addition to NGAL, Human Leukocyte Antigen (HLA) typing is another crucial factor in kidney transplantation outcomes. Both NGAL and HLA typing are integral to transplant management, as they significantly contribute to the transplant's overall success. While NGAL provides critical insights into early kidney injury and potential graft outcomes, HLA typing ensures compatibility and helps reduce the risk of rejection. The potential role of NGAL as an immunomodulatory molecule stems from its capacity to promote immune tolerance by enhancing HLA-G expression and facilitating the expansion of T-regulatory cells in healthy individuals. In this study, we attempted to correlate the sNGAL level with the degree of mismatch to determine the possibility of using sNGAL as a predictive value for the occurrence of damage to the transplanted kidney, based on the degree of mismatch known in advance during the patient's preparation before the kidney transplant operation.

Records from the kidney transplant center were analyzed to document the attributes of eligible patients. One patient was chosen to take part in the study, with histological type categorized based on the HLA system. The degree of mismatch was assessed using the A-B-DR classification, while serum creatinine and NGAL levels were evaluated. Additional details, including age, sex, and the length of hemodialysis before transplantation, were likewise recorded.

The study revealed that NNGAL levels in patients correlated directly with the degree of mismatch . Higher sNGAL levels were observed with greater mismatch, particularly at the HLA-Dr level, while a lower sNGAL level was noted when incompatibility also occurred at the HLA-Dr level. Additionally, sNGAL levels showed a direct relationship with increasing serum creatinine. It was also found that sNGAL levels rose in conjunction with longer durations of hemodialysis before transplantation.

In summary, NGAL and HLA typing are both vital in the context of kidney transplantation. NGAL serves as an important biomarker for kidney injury and graft function, while HLA typing is essential for ensuring immunological compatibility and minimizing rejection risks. Linking sNGAL levels with patients' existing HLA patterns could serve as an indicator for chronic rejection or early-stage renal damage. This approach could assist physicians in proactively managing the condition to minimize the risk of graft loss. Validation through larger, multicenter studies might strengthen these findings.