Introduction: Cryoglobulinemia refers to the presence of cryoglobulins (CGs) in serum, encompassing a group of diseases caused by the type of circulating GC. Cryoglobulinemic glomerulonephritis (CryoGN) is the principal manifestation of renal involvement. The diagnosis may be challenging because the hallmark of cryoglobulinemia is the detection of cryoglobulin in the serum. However, cases of CryoGN without serological evidence of cryoglobulins are not uncommon in clinical practice, often diagnosed by anatomopathological findings in the renal biopsy. Case presentation: We report the case of an 86-year-old male who developed renal impairment, nephritic syndrome, and nephrotic-range proteinuria, without serological evidence of cryoglobulins; associated with staphylococcal bacteremia without apparent focus. Renal biopsy and pathological examination showed a membranoproliferative glomerulonephritis (MPGN) pattern with CD61 negative pseudothrombi. Immunofluorescence microscopy showed atypical IgA dominant deposits. Electron microscopy revealed amorphous subendothelial and mesangial deposits; and organized electrodense deposits within capillary loops (pseudothrombi) with microtubular substructure measuring 20-40 nm thick. These findings were consistent with seronegative-CryoGN and microtubulars organized atypical IgA-dominant deposits. Discussion/Conclusion: In this report we discuss the clinical, analytical and histopathologic findings of a rare case of CryoGN without serologic evidence of CGs. Regarding the etiology that triggered the glomerular disease in our patient, we conducted an exhaustive study in order to determine the underlying cause of the CryoGN. At the time of biopsy, the patient had an active staphylococcal bacteremia. There are reports that postulate that staphylococcal antigens drive activation of immune system and in consequence, could cause this rare form of IgA-dominant glomerulonephritis with cryoglobulinemic features. After ruling out other causes of cryoglobulinemia, we discuss a plausible causal relationship of the staphylococcal infection in the pathogenesis of CryoGN in our patient.

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SGLT-2i are the new standard of care for diabetic kidney disease (DKD), but previous studies have not included patients on kidney replacement therapy (KRT). Due to their high risk of cardiovascular, renal complications, and mortality, these patients would benefit the most from this therapy. Residual kidney function (RKF) conveys a survival benefit and cardiovascular health among hemodialysis (HD) patients, especially those on incremental hemodialysis (iHD). We retrospectively describe the safety and efficacy of SGLT2i regarding RKF preservation in seven diabetic patients with different clinical backgrounds who underwent iHD (one or two sessions per week) during a 12-month follow-up. All patients preserved RKF, measured as residual kidney urea clearance (KrU) in 24 h after the introduction of SGLT2i. KrU levels improved significantly from 4.91 ± 1.14 mL/min to 7.28 ± 1.68 mL/min at 12 months (p = 0.028). Pre-hemodialysis blood pressure improved 9.95% in mean systolic blood pressure (SBP) (p = 0.015) and 10.95% in mean diastolic blood pressure (DBP) (p = 0.041); as a result, antihypertensive medication was modified. Improvements in blood uric acid, hemoglobin A1c, urine albumin/creatinine ratio (UACR), and 24 h proteinuria were also significant. Regarding side effects, two patients developed uncomplicated urinary tract infections that were resolved. No other complications were reported. The use of SGLT2i in our sample of DKD patients starting iHD on a 1–2 weekly regimen appears to be safe and effective in preserving RKF.

Objetivo: Estudiar la correlación existente entre la recolección de proteinuria de veinticuatro horas y el índice proteinuria/creatinina tomada de una alícuota de la misma muestra y analizar las variables que afectan la correlación. Material y Métodos: Se seleccionaron 100 personas adultas de diversos servicios hospitalarios y ambulatorios del Hospital Nacional Cayetano Heredia a quienes se les solicitó proteinuria en 24 horas por diversas circunstancias. La proteinuria y la creatinina en orina se midieron utilizando auto-analizadores con técnicas de química seca. Resultados: Un paciente fue excluido por dudosa recolección de la muestra. Hubo 18% varones y 82% mujeres. En la muestra hubo 38% de pacientes gestantes La correlación obtenida en toda la muestra tuvo un r= 0,74 (p<0,001), evidenciándose que la dispersión de los datos ocurrió en presencia de pacientes con proteinuria superior a 7 g/día; con volumen urinario menor a 600 ml/día y pacientes gestantes Al excluir estos datos la correlación tuvo un r= 0,95, p<0,001 (r2 = 0,88, IC 95% 0,79-0,93, p<0,001). Conclusión: Existe una alta correlación entre proteinuria en 24 horas y el índice proteinuria/creatinina tomada en una alícuota. Existen variables críticas que afectan la correlación entre estos dos parámetros: diuresis dudosas, gran proteinuria y pacientes gestantes. (Rev Med Hered 2010;21:59-64).