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Introducción: En Perú la incidencia de glomeruloesclerosis focal y segmentaria primaria ha aumentado considerablemente durante la última década y actualmente es la primera causa de glomerulonefritis primaria en adultos. Por su prevalencia y alta probabilidad de progresar a insuficiencia renal crónica terminal, se buscaron factores con valor pronóstico para supervivencia renal y remisión de proteinuria. Pacientes y Métodos: Cohorte histórica de 44 pacientes. Estudiamos las características clínicas e histológicas al momento de la biopsia renal y la función renal al seguimiento. Los desenlaces principales fueron: deterioro renal (incremento de creatinina >50% y/o insuficiencia renal terminal) y remisión de proteinuria (parcial 0.3-3.49 g/día y completa < 0.3g/día). Se usaron curvas de Kaplan-Meier y regresión multivariable de Cox. Resultados: El 59% de los pacientes fueron varones. El 54.5% presentó insuficiencia renal, 53.5% síndrome nefrótico y 43.2% hipertensión arterial al momento de la biopsia. Los tipos histológicos fueron: no especificado 75%, celular 13.6%, tip 6.8% e hiliar 4.5%. El 56.8% recibió esteroides por 6.2 ± 4.1 meses y el 32% fue corticodependiente. La función renal empeoró en el 18.2%. El 37.8% logró remisión parcial y 32.4% remisión completa de proteinuria. El tratamiento con esteroides, con antihipertensivos y los depósitos glomerulares de IgM y C3 se asociaron a mayor supervivencia renal. El tratamiento con esteroides fue el único factor que predijo independientemente, mayor supervivencia renal (hazard ratio o HR: 0.07, 0.01-0.9) y remisión de proteinuria (HR 0.2, 0.04-0.9). La hipertensión arterial (HR: 6.2, 1.1-35.2), la insuficiencia renal (HR: 2.9, 1.1-7.6), la variante celular y la fibrosis intersticial (HR: 5.2, 1.02-26.7) fueron indicadores de pobre remisión de proteinuria. Conclusiones: En glomeruloesclerosis focal y segmentaria primaria, el tratamiento con esteroides determinó mayor supervivencia renal y mayor probabilidad de remisión de proteinuria. La presencia de insuficiencia renal y fibrosis intersticial determinaron no remisión de proteinuria.
Palabras clave:
síndrome nefrótico
Palabras clave:
Glomeruloesclerosis focal y segmentaria
Palabras clave:
insuficiencia renal
Palabras clave:
supervivencia renal
Background: In Peru, the incidence of primary focal segmental glomerulosclerosis (PFSGS) has considerably increased in the last decade and at the present; it is the first cause of primary glomerulonephritis in adults. Because of its prevalence and high probability to progress to end-stage renal disease (ESRD), we searched for factors with prognostic value for renal survival and proteinuria remission. Subjects and methods: Historical cohort of 44 patients. We studied clinical and histological characteristics at the time of renal biopsy and clinical condition and renal function at the end of follow- up. Principal outcomes: renal impairment &
Keywords:
nephrotic syndrome
Keywords:
Focal segmental glomerulosclerosis
Keywords:
renal failure
Keywords:
renal survival
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INTRODUCTION
Focal segmental glomerulosclerosis (FSGS) is a clinical and pathological syndrome characterized by proteinuria and segmental sclerosis of some glomeruli, with fusion of podocyte processes. Obliteration of glomeruli by cell proliferation or accumulation of extracellular collagen matrix may occur.1 FSGS is classified as primary in the absence of an underlying disease. Clinical signs of FSGS are variable, but most patients have proteinuria in the nephrotic range, arterial hypertension (AHT), and some grade of kidney function impairment.2 Primary FSGS has a variable prognosis depending on the ethnic, clinical, and histopathological characteristics, treatment scheme,
treatment response, and the different observation periods. There is however agreement in that patients with the collapsing and cellular histological variants have a poorer prognosis and experience a relatively rapid kidney function impairment. 3-6 Clinically, it is estimated that 50% of patients with persistent proteinuria in the nephrotic range will progress to end-stage renal disease (ESRD) within 5-10 years. Untreated patients have a poor prognosis, reaching the end stage within 3-6 years.7,8
An increasing incidence of primary FSGS has been reported in several countries. In the United States, FSGS is the
most common cause of nephrotic syndrome and ESRD in black and white adults with primary glomerulonephritis.9-11 A similar trend has been noted in Latin America.12-14 In Peru, FSGS has displaced membranoproliferative glomerulonephritis as the most common primary glomerulonephritis.15,16 However, recent European studies do not show this trend. Thus, in Spain, the glomerulonephritis registry of the SEN17 showed no changes in incidence between 1994 and 2005. Similarly, Cameron18 found no differences in London in the 1970-2000, during which the incidence rate remained at 20%. In Italy,19 incidence changed from 11.7% to 10.4% from 1987 to 1993. Few studies have been conducted in Peru on primary FSGS, and because of its epidemiological significance and its risk of progressing to ESRD, a search was made for clinical and histological factors having a prognostic value in the evolution of kidney function and that would allow for implementing a rational and appropriate therapeutic approach based on current evidence.
PATIENTS AND METHODS
Study design and population
A longitudinal, retrospective study was conducted on a historical cohort of patients diagnosed whit primary FSGS based on a kidney biopsy who attended the department of nephrology of Hospital Nacional Arzobispo Loayza from January 1994 to December 2004. Medical records and pathology reports of patients were reviewed, and their demographic, clinical, laboratory, and histological data were recorded at the time of kidney biopsy. Among 64 patients with a histological diagnosis of FSGS, 51 patients had primary FSGS. Clinical follow-up and home visit were performed in 44 patients (86.3%), while the remaining 7 patients moved and could not be located. These 44 patients formed the final analysis sample. Patients older than 15 years with a diagnosis of primary FSGS, a renal
biopsy sample with 8 or more glomeruli, and light microscopy and immunofluorescence studies were enrolled into the study. Patients with concomitant nephropathy, obesity &
Focal segmental glomerulosclerosis (FSGS) is a clinical and pathological syndrome characterized by proteinuria and segmental sclerosis of some glomeruli, with fusion of podocyte processes. Obliteration of glomeruli by cell proliferation or accumulation of extracellular collagen matrix may occur.1 FSGS is classified as primary in the absence of an underlying disease. Clinical signs of FSGS are variable, but most patients have proteinuria in the nephrotic range, arterial hypertension (AHT), and some grade of kidney function impairment.2 Primary FSGS has a variable prognosis depending on the ethnic, clinical, and histopathological characteristics, treatment scheme,
treatment response, and the different observation periods. There is however agreement in that patients with the collapsing and cellular histological variants have a poorer prognosis and experience a relatively rapid kidney function impairment. 3-6 Clinically, it is estimated that 50% of patients with persistent proteinuria in the nephrotic range will progress to end-stage renal disease (ESRD) within 5-10 years. Untreated patients have a poor prognosis, reaching the end stage within 3-6 years.7,8
An increasing incidence of primary FSGS has been reported in several countries. In the United States, FSGS is the
most common cause of nephrotic syndrome and ESRD in black and white adults with primary glomerulonephritis.9-11 A similar trend has been noted in Latin America.12-14 In Peru, FSGS has displaced membranoproliferative glomerulonephritis as the most common primary glomerulonephritis.15,16 However, recent European studies do not show this trend. Thus, in Spain, the glomerulonephritis registry of the SEN17 showed no changes in incidence between 1994 and 2005. Similarly, Cameron18 found no differences in London in the 1970-2000, during which the incidence rate remained at 20%. In Italy,19 incidence changed from 11.7% to 10.4% from 1987 to 1993. Few studies have been conducted in Peru on primary FSGS, and because of its epidemiological significance and its risk of progressing to ESRD, a search was made for clinical and histological factors having a prognostic value in the evolution of kidney function and that would allow for implementing a rational and appropriate therapeutic approach based on current evidence.
PATIENTS AND METHODS
Study design and population
A longitudinal, retrospective study was conducted on a historical cohort of patients diagnosed whit primary FSGS based on a kidney biopsy who attended the department of nephrology of Hospital Nacional Arzobispo Loayza from January 1994 to December 2004. Medical records and pathology reports of patients were reviewed, and their demographic, clinical, laboratory, and histological data were recorded at the time of kidney biopsy. Among 64 patients with a histological diagnosis of FSGS, 51 patients had primary FSGS. Clinical follow-up and home visit were performed in 44 patients (86.3%), while the remaining 7 patients moved and could not be located. These 44 patients formed the final analysis sample. Patients older than 15 years with a diagnosis of primary FSGS, a renal
biopsy sample with 8 or more glomeruli, and light microscopy and immunofluorescence studies were enrolled into the study. Patients with concomitant nephropathy, obesity &
