Caracterización de enfermedades glomerulares: análisis de 22 años de biopsias renales / Frequency of glomerular diseases in an analysis of 550 kidney biopsies

BACKGROUND: The frequency of glomerular diseases is dynamic and varies according to geographic area. AIM: To evaluate the frequency of primary and secondary glomerulopathies, their demographic profile and main clinical characteristics. MATERIAL AND METHODS: Renal biopsies from native kidneys performed between 1999 and 2020 were retrospectively reviewed. Demographic characteristics, clinical presentation, most relevant laboratory tests, frequency of primary and secondary glomerulopathies were analyzed. RESULTS: We analyzed 550 kidney biopsies from patients with a median age of 48 years (64% females). Nephrotic syndrome was the main indication for renal biopsy. Primary and secondary glomerulopathies occurred with similar frequency. Within the primary glomerulopathies, membranous nephropathy (34.1%) was the most common, followed by IgA nephropathy (31.1%) and focal segmental glomerulosclerosis (14.1%). Among the secondary glomerulopathies, lupus nephropathy was the most common (41.7%), followed by pauciimmune glomerulonephritis (27.1%) and diabetic nephropathy (6.4%). When comparing the results with other regions, significant differences were observed with reported frequencies in United States, Europe, Asia and the rest of Latin America. CONCLUSIONS: The most common primary glomerulopathies were membranous nephropathy and IgA nephropathy. Among the secondary glomerulopathies lupus nephropathy and pauci-immune glomerulonephritis were the most common. Compared to international registries, we observed a high proportion of membranous nephropathy and pauci-immune glomerulonephritis.

Polineuropatía por amiloidosis por transtiretina de inicio tardío. Caso clínico / Late-onset hereditary transthyretin amyloidosis with polyneuropathy. Report of one case

Hereditary transthyretin amyloidosis is a multisystemic autosomal dominant genetic disorder characterized by progressive distal sensory-motor polyneuropathy or restrictive cardiomyopathy, secondary to amyloid deposits. Its pathogenesis lies in the TTR gene mutation, and the Val50Met mutation is the most frequent. Patients have significant differences in the onset and severity of clinical presentation according to their country of origin. The diagnosis of this pathology is complex, even more in countries where it is not considered endemic. However, early suspicion and management are essential to improve survival and avoid unnecessary diagnostic and therapeutic strategies. We report a 69-year-old woman who presented a sensory-motor polyneuropathy, predominantly sensory, associated with distal neuropathic pain and bilateral vitritis. The history of her Italian father with polyneuropathy of unspecified etiology stood out. A vitreous biopsy identified amyloid substance deposits (congo red positive). These were also confirmed on a superficial peroneal nerve biopsy. During the etiological study of her polyneuropathy, an increased Kappa/Lambda index of 2.55 mg/L stood out. Therefore, light chain amyloidosis was suspected, and chemotherapy treatment was indicated without favorable response. After 10 years of progressive neurological and ophthalmological involvement, a genetic study confirmed the first case of late-onset hereditary transthyretin amyloidosis Val50Met with polyneuropathy in Chile.

Prognostic impact of renal failure recovery in patients with newly diagnosed multiple mieloma / Impacto pronóstico de remisión renal en pacientes con mieloma múltiple de reciente diagnóstico

ABSTRACT Background Renal failure (RF) is a common complication in patients with newly diagnosed multiple myeloma (NDMM). Aim To evaluate the frequency of RF in NDMM patients, and the prognostic impact of its reversibility. Material and Methods A retrospective study evaluating demographic and clinical characteristics of 154 consecutive patients with NDMM was carried out. Estimated glomerular filtration rate (eGFR) was calculated at the beginning and at the end of the induction therapy. In addition, we evaluated renal responses (RR) according to the International Myeloma Working Group (IMWG) criteria. The induction regimen was based on thalidomide in all cases. Results Fifty-three patients had RF (34.4%). Complete renal response (RR) was achieved in 51%. Three years overall survival in patients without RF, with RF and complete RR, and patients with RF and any other RR, was 66, 47 and 13%, respectively. Median survival was 53, 27 and 6 months, respectively (p < 0.01). In the multivariate analysis, RF and hypercalcemia were independent predictors of a worse outcome. Conclusions Achieving a complete RR in patients with NDMM, is associated with a better survival.

Antecedentes La falla renal (FR) es una complicación frecuente en pacientes con mieloma múltiple (MM). Objetivo Evaluar la frecuencia de FR en pacientes con reciente diagnóstico de MM y determinar la importancia pronóstica de su reversibilidad. Material y Métodos Se realizó un estudio retrospectivo de 154 pacientes consecutivos con MM. La función renal se evaluó mediante la tasa estimada de filtración glomerular al inicio y final de la terapia de inducción. Además, evaluamos las respuestas renales (RR) de acuerdo con los criterios del International Myeloma Working Group (IMWG). El régimen de inducción se basó en talidomida en todos los casos. Resultados Cincuenta y tres pacientes presentaron FR (34,4%) al diagnóstico. La RR completa se logró en 51%. La sobrevida global (SG) a 3 años en pacientes sin FR, con FR y RR completa, y pacientes con FR y cualquier otra RR, fue de 66, 47 y 13%, respectivamente. La SG media fue de 53, 27 y 6 meses (p < 0,01), respectivamente. En el análisis multivariado, la FR y la hipercalcemia fueron factores independientes de menor sobrevida. Conclusiones Lograr una RR completa en pacientes con MM recién diagnosticado se asocia con una mejor sobrevida.

AL amyloidosis in the Chilean public health system: a pending debt: multicenter study of the Chilean Monoclonal Gammopathies Cooperative Group / Amiloidosis AL en el sistema público de Chile: una deuda pendiente: estudio multicéntrico

ABSTRACT Background: Immunoglobulin light chain (AL) amyloidosis is a rare and underdiagnosed entity. Aim: To characterize patients with AL amyloidosis in Chilean public health centers. Material and Methods: We conducted a retrospective, multicenter study. Public centers of the Chilean Monoclonal Gammopathies Cooperative Group were asked to search for patients with AL amyloidosis in their databases. Epidemiological, clinical and laboratory characteristics were evaluated. Results: Forty-two patients aged 22 to 84 years were found. Twenty four percent had localized AL amyloidosis; 64% had a lambda light chain clone; 47% were associated with multiple myeloma and 9% with non-Hodgkin lymphoma. The most commonly involved organ was the kidney (76%). Serum free light chains were measured in 31% and an echocardiogram was performed in 74% of patients. Seventeen percent of patients received only palliative care, 17% were treated with bortezomib, 21% with thalidomide, and 40% with melphalan. No patient was transplanted. The mean overall survival (OS) of the group was 19 months. The 5-year OS was 28%. Conclusions: It is important to obtain these realistic, national data to initiate strategies to improve early diagnosis and proper management of this disease.

La amiloidosis AL es una entidad poco frecuente y subdiagnosticada. Mientras todo el mundo discute sobre las nuevas herramientas diagnósticas y terapéuticas, en Chile y en América Latina en general, estamos lejos de esa realidad. El objetivo del presente estudio fue caracterizar a los pacientes con amiloidosis AL en centros del sistema público de nuestro país. Se realizó un estudio retrospectivo, multicéntrico, descriptivo. Los centros públicos del grupo cooperativo hematológico chileno buscaron en sus bases de datos pacientes diagnosticados con amiloidosis AL. Se evaluaron las características epidemiológicas, clínicas y de laboratorio. La edad media fue de 65 años. A 24% de los pacientes se les diagnosticó amiloidosis AL localizada; 64% tuvo paraproteína con cadena ligera lambda; 47% se asoció con mieloma múltiple y 9% con linfoma no Hodgkin. El órgano afectado con mayor frecuencia fue el riñón (76%). Las cadenas ligeras libres de suero se realizaron en 31% y ecocardiograma en 74%. El 17% recibió solo cuidados paliativos, 17% recibió tratamiento con bortezomib, 21% con talidomida y 40% con melfalán. Ningún paciente fue trasplantado. La media de sobrevida global (SG) del grupo fue de 19 meses. La SG a 5 años fue de 28%. Es importante reportar estos resultados nacionales para iniciar estrategias que mejoren tanto el diagnóstico temprano como el tratamiento de esta patología. Por lo tanto, mejorar la sospecha diagnóstica es crucial.

Resultados a largo plazo en trasplante renal de donantes con criterios expandidos / Long-term outcomes with expanded criteria donors in kidney transplantation

Background: Kidney transplantation of expanded criteria deceased donors (DCE) has become a common clinical practice. However, DCE outcomes are inferior compared to kidney transplants from standard criteria donors (DCS). Aim: To evaluate intermediate and long-term outcomes of DCE transplanted patients. Material and Methods: Cadaveric kidney transplants were evaluated using a retrospective cohort of eight consecutive years. Complications and long-term function of the transplant were assessed in DCE and DCS kidney recipients. Results: Of 213 patients analyzed, 34 (16%) underwent DCE transplantation. DCS recipients spent more time on the waiting list for transplantation (p = 0.04). DCE recipients showed higher frequency of surgical complications (p = 0.04), vascular complications (p = 0.02), acute transplant rejection (p = 0.05), and hospitalizations (p = 0.01). Creatinine (mg/dL) in DCE and DCS recipients was 2.3 and 1.5 respectively at year one (p < 0.01) and 2.6 and 1.6 respectively at year five (p < 0.01). Graft survival in the DCE group was significantly lower at 5 years (61 and 89% respectively, p < 0.01). Conclusions: DCE grafts are associated with lower survival, higher hospitalization rate and commonly develop surgical complications and rejections.