A 78-Year-Old Man with Chronic Kidney Disease and Monoclonal Gammopathy Who Developed Post-Transplant C3 Glomerulopathy - Recurrence or De Novo? A Case Report and Literature Review.

BACKGROUND The incidence of glomerular disease recurrence in kidney transplant patients varies according to type of glomerulopathy; therefore, it is important to know the primary chronic kidney disease etiology. C3 glomerulopathy (C3G) is characterized by deposits of C3 in immunofluorescence and its pathogeny is based on the dysregulation of the alternative complement pathway. C3G has a high recurrence rate and, given its low prevalence, only case series have been published. A higher rate of recurrence and a more aggressive course have been described in association with monoclonal gammopathy (MG). CASE REPORT We describe the case of a 78-year-old man with chronic kidney disease of unknown etiology (no significant proteinuria) and monoclonal IgGl gammopathy with low risk of progression, who received a kidney transplant, presenting accelerated deterioration of kidney function. Histopathology showed predominant C3 deposits in immunofluorescence, compatible with C3 glomerulonephritis (C3GN). He was treated with eculizumab during 4 weeks while the study was completed. The response to treatment was not favorable and the patient remained in the dialysis program. CONCLUSIONS Further studies are needed to explain the pathogenic mechanisms of complement alternative pathway dysregulation mediated by monoclonal component in patients with C3GN and MG. Patients older than 50 years who are on a waiting list for kidney transplantation should have an MG detection study. The information provided to patients with MG on a waiting list for kidney transplantation should include not only the possibility of hematologic progression but also the recurrence/de novo appearance of associated kidney pathology.

[Assessment of long-term renal function after nephrectomy. Study of 53 patients]. / Estudio de la función renal a largo plazo en 53 pacientes con nefrectomía por diversas causas.

BACKGROUND AND OBJECTIVE: Patients with unilateral nephrectomy maintain the remaining kidney function over time, as it has been described in healthy kidney donors. PATIENTS AND METHOD: We performed a cross-sectional study of 53 patients who were followed 5 or more years after nephrectomy. Serum creatinine, BUN, Glomerular Filtration Rate (GFR) (24 hours urine collection and Cockcroft formula), microalbuminuria, proteinuria, Body Mass Index and the annual loss rate of renal function were measured or calculated over the follow-up period. We retrospectively considered the presence of risk factors like diabetes, hypertension, microalbuminuria, dyslipemia, smoking habit, obesity and ACE inhibitors or angiotensin-receptor antagonists treatment. We divided our patients into two groups: group I (normal or mild renal failure: GFR > 50 cc/min and or serum creatinine < 1.4 mg/dL) and group II (moderate or severe renal failure). RESULTS: The main cause of nephrectomy was renal tuberculosis, followed by lithiasis and pyonephrosis. In addition, 7.5% of patients were kidney donors. At the time of study, 22.7% had diabetes, 60.4% hypertension and 39.6% were obese. The mean age was 60 years (37 years at the moment of nephrectomy). The GFR final mean was 53.6 cc/min (58.8 cc/min by Cockcroft formula). The mean renal function loss rate was 1 cc/min/year. 35% of the patients had moderate or severe kidney failure and were included in group II; 32% had proteinuria and 56.6% had abnormal microalbuminuria. The univariate risk factors analysis for the development of renal failure showed inter-group statistical significative differences in current age, nephrectomy age, microalbuminuria, proteinuria, and hypertension prevalence (p = 0.008). With regard to the progression rate, we found a significant correlation with final microalbuminuria (r = 0.358, p = 0.03). Current age and final proteinuria were found to be significant risk factors in the multivariate analysis. CONCLUSIONS: A high prevalence of renal insufficiency was found among patients with unilateral nephrectomy, which is mainly related to age and proteinuria. The renal function loss rate is slow and is influenced by microalbuminuria.