Overlap Syndrome of Diffuse Systemic Sclerosis, Sjögren Syndrome, and ANCA-Associated Renal-Limited Vasculitis: Three Entities in One Patient - Case Report.

Introduction: The presence of three different entities in a single patient is usually of clinical interest and mostly anecdotal. The overlap of systemic sclerosis (SSc), Sjögren syndrome (SS), and ANCA-associated renal-limited vasculitis has been reported only once previously. Case Presentation: A 61-year-old female was evaluated at consultation with 2 years of symptomatology, presenting cardboard-like skin, sclerodactyly, limited oral opening, and dry skin and eyes. She was admitted for progressive renal failure (serum creatinine, 5.5 mg/dL). Her serology work-up showed positive anti-SCL-70, anti-Ro, anti-La, anti-MPO, and antinuclear antibodies. Renal biopsy was performed and confirmed histological findings for SSc, SS, and ANCA-associated vasculitis with active extracapillary glomerulonephritis with fibrous predominance (EUVAS-Berden sclerotic class), active tubulointerstitial nephritis, focal tubular injury, and moderate chronic arteriolopathy. Treatment with 6 monthly doses of methylprednisolone and cyclophosphamide was established. At the last follow-up, the patient maintained a stable serum creatinine level of 2.6 mg/dL and had decreased proteinuria, no erythrocyturia, and no requirement for renal replacement therapy. Conclusion: Systemic sclerosis is a rare autoimmune disease; nevertheless, overlap with Sjögren syndrome is relatively common, although its association with ANCA vasculitis is anecdotal. Diagnostic integration presents a challenge for nephrologists to define the prognosis and a specific treatment.

Immunohistochemical analysis of caspase expression in the brains of individuals with obesity or overweight.

Mechanisms underlying the negative effects of obesity on the brain are still unknown. Obesity is associated with oxidative stress in the brain and neuroinflammation that promotes neurodegenerative diseases. Chronic low-grade neuroinflammation in obesity could be associated with lower volumes of gray matter and lower neuronal density. If neuroinflammation mediated by the expression of cytokines and chemokines leads to apoptosis, this can be assessed by examining caspase expression. The aim of this study was to compare the expression of caspases in the 16 brains of donors with obesity/overweight (n = 8; Body Mass Index [BMI] = 31.6 ± 4.35 kg/m2; 2 females; Age = 52.9 ± 4.76 years) and normal weight (n = 8; BMI = 21.8 ± 1.5 kg/m2; 3 females; Age = 37.8 ± 19.2 years). Sixteen human brain samples were processed. Serial paraffin sections were examined by anti-caspase immunochemistry (caspase-3, caspase-4, caspase-6, caspase-1, caspase-8, and caspase-9 antibodies). Postmortem samples of cerebral cortex tissue were captured as photomicrographs and the images obtained were analyzed using ImageJ software to obtain the percentage of positive caspase expression. Nonparametric Mann-Whitney U tests were performed to compare caspase expression between samples from donors with obesity/overweight and normal weight. Taking into consideration the immunohistochemistry results, the Search Tool for the Retrieval of Interacting Genes was used to model molecular interactions. Results showed that brain samples from individuals with obesity/overweight exhibited significantly greater values of positive expression for Caspase-1 (U = 16.5, p = 0.05, Cohen d = 0.89) and -8 (U = 15, p = 0.03, Cohen d = 0.99) than those from donors with normal weight. This study contributes to the knowledge about the inflammatory effects of obesity/overweight on brain, suggesting the activation of the alternative inflammasome pathway in which interact caspase-1 and -8.

Podocytopathy Associated with IgA Nephropathy in Pregnancy: A Challenging Association.

IgA nephropathy is the most common form of primary glomerulonephritis. While associations of IgA and other glomerular diseases have been described, the association of IgA nephropathy with "primary" podocytopathy is rare and has not been reported in pregnancy, due in part to the infrequent use of kidney biopsy during pregnancy, and a frequent overlap with preeclampsia. We report the case of a 33-year-old woman with normal kidney function, referred in the 14th gestational week of her second pregnancy, due to nephrotic proteinuria and macroscopic hematuria. The baby's growth was normal. The patient reported episodes of macrohematuria one year previously. A kidney biopsy performed at 18 gestational weeks confirmed IgA nephropathy, associated with extensive podocyte damage. Treatment with steroids and tacrolimus led to remission of proteinuria and a healthy baby, adequate for gestational age, was delivered at 34 gestational weeks and 6 days (premature rupture of membranes). Six months after delivery, proteinuria was about 500 mg per day, with normal blood pressure and kidney function. This case highlights the importance of timely diagnosis in pregnancy and underlines that good maternal and fetal outcomes can be achieved with appropriate treatment, even in complex or severe cases.

Glomerular diseases in pregnancy: pragmatic recommendations for clinical management.

Our understanding of the various aspects of pregnancy in women with kidney diseases has significantly improved in the last decades. Nevertheless, little is known about specific kidney diseases. Glomerular diseases are not only a frequent cause of chronic kidney disease in young women, but combine many challenges in pregnancy: immunologic diseases, hypertension, proteinuria, and kidney tissue damage. An international working group undertook the review of available current literature and elicited expert opinions on glomerular diseases in pregnancy with the aim to provide pragmatic information for nephrologists according to the present state-of-the-art knowledge. This work also highlights areas of clinical uncertainty and emphasizes the need for further collaborative studies to improve maternal and fetal health.

Kidney biopsy during pregnancy: a difficult decision. A case series reporting on 20 patients from Mexico.

BACKGROUND: Kidney biopsy is a routine procedure in the diagnosis of kidney disease, but during pregnancy it carries potential adverse effects for both mother and child, aside from the challenges of obtaining adequate tissue samples. Nevertheless, a precise diagnosis is necessary when specific and potentially toxic treatments are to be used during pregnancy. The present report presents our experience with regard to the usefulness and safety of kidney biopsies during pregnancy. METHODS: Retrospective analysis of clinical indications, complications, histopathological diagnoses, and treatment of patients who had kidney biopsies done at a single academic center during gestation weeks 11-30 between January 2015 and January 2019. RESULTS: Kidney biopsies were carried out in 20 pregnant patients with nephrotic proteinuria. Biopsy was adequate in all patients. The histological diagnoses included focal segmental glomerulosclerosis (collapsing, tip and perihiliar varieties), membranous lupus nephropathy, diabetic nephropathy, and IgA nephropathy. Treatment was associated with reduction of proteinuria in 17 patients and reduction of serum creatinine in 9 out of 11 patients who had serum creatinine ≥ 1 mg/dl at the time of biopsy. There was one major bleeding complication that required transfusion of one unit of blood. There was a high incidence of preeclampsia, preterm delivery, and low birth weight despite appropriate kidney disease therapy. CONCLUSIONS: Kidney biopsy may be done during pregnancy when therapeutic decisions depend on a precise pathologic diagnosis.

Association between kidney biopsy findings in CKD patients with diabetes and renal replacement therapy initiation, a perspective from a low-middle income country.

Kidney disease in diabetes mellitus is usually explained by diabetic kidney disease, but other superimposed etiologies occur frequently. The distinction between diabetic kidney disease and non-diabetic kidney disease can only be made by performing kidney biopsy. Our objective was to evaluate the association of diabetic kidney disease, non-diabetic kidney disease, or both with renal replacement therapy initiation. This is a retrospective cohort that included patients with type 2 diabetes mellitus for whom a kidney biopsy was indicated. Subjects were followed-up for 5 years, until renal replacement therapy initiation or were lost to follow up. One hundred and forty-one patients were included, 53 (39%) had diabetic kidney disease, 13 (9%) had non-diabetic kidney disease and 75 (54%) had both. Ninety-four percent of the cohort initiated renal replacement therapy during the 5-year follow-up. Higher degree of fibrosis was associated with a trend towards higher risk of requiring renal replacement therapy. In addition, the combined diabetic kidney disease + non-diabetic kidney disease group was associated with higher need of renal replacement therapy initiation when compared to the diabetic kidney disease group.

Differential Th follicular cell subsets in minor salivary glands of patients with primary Sjögren's syndrome and systemic lupus erythematosus associated with Sjögren's syndrome.

OBJECTIVES: T follicular helper cells (Tfh) have been recognised in minor salivary glands (MSG) of patients with primary Sjögren's syndrome (pSS). Nevertheless, if the Tfh1, Tfh2, Tfh17, Tfr phenotype is different when comparing pSS and associated SS in systemic lupus erythematosus (SLE) is unknown. METHODS: We included MSG biopsies from 8 pSS, 8 SLE/SS patients, 7 SLE patients, and 2 non-SS sicca patients. To determine the subpopulation of Tfh, a double-staining procedure for transcription factor B cell lymphoma 6 (Bcl-6)+/IL-17A+, Bcl6+/IL-4+, Bcl6+/IFN-γ+, and Bcl6+/Foxp3+ cells was performed. We estimated the mean percentage of positively staining cells in four fields per sample. RESULTS: Tfh1, Tfh2, and Tfh17 cells were highly expressed in pSS compared with the rest of the groups; conversely, in patients with SLE/SS predominated, the Tfh17 and in SLE patients the Tfh1 cells. Regulatory Tfh cells (Tfr) were similar in pSS and the rest of the patients. However, the lowest frequency was found in the SLE group. A positive correlation was observed between anti-Ro/SSA autoantibody and Tfh17 subset (r=0.726, p=0.0001); and with the (Tfh2+Tfh17)/Tfh1 ratio (r=0.844, p<0.0001) in the MSG of patients with pSS. CONCLUSIONS: We showed a differential Tfh profile in primary SS and SLE with associated SS. Whether this Tfh differential profile participates in the increased risk of lymphoproliferative disease in pSS compared with associated SS, or other outcomes, is yet to be determined in future studies.

Collapsing Lesions and Focal Segmental Glomerulosclerosis in Pregnancy: A Report of 3 Cases.

The relationship between focal segmental glomerulosclerosis (FSGS) and pregnancy is complex and not completely elucidated. Pregnancy in patients with FSGS poses a high risk for complications, possibly due to hemodynamic factors, imbalance between angiogenic and antiangiogenic factors, and hormonal conditioning. Although poor clinical outcomes associated with collapsing FSGS are common outside of pregnancy, the prognosis during pregnancy is not well documented. We report 3 patients who developed collapsing FSGS during pregnancy, 2 of whom had presumed underlying FSGS. Two patients underwent biopsy during pregnancy, and 1, during the puerperium. None of the 3 patients improved spontaneously after delivery, and 1 experienced a rapid deterioration in kidney function and proteinuria after delivery. Aggressive immunosuppressive therapy led to a full response in 1 case (without chronic lesions) and to partial responses in the remaining 2 cases. These cases suggest that collapsing lesions should be considered in patients with FSGS who develop a rapid increase in serum creatinine level or proteinuria during pregnancy and that these lesions may at least partially respond to treatment.

Acute IgA-Dominant Glomerulonephritis Associated with Syphilis Infection in a Pregnant Teenager: A New Disease Association.

Chronic kidney disease (CKD) is increasingly recognized as a risk factor in pregnancy; the differential diagnosis between CKD and preeclampsia (PE) may be of pivotal importance for pregnancy management and for early treatment of CKD. Acknowledging this connection may be useful also in a wider context, such as in the case reported in this paper, which for the first time describes an association between syphilis infection and IgA-dominant glomerulonephritis. A 16-year-old woman, referred to a general hospital due to a seizure, was found to be unknowingly pregnant. Based on hypertension and nephrotic proteinuria, she was initially diagnosed with PE. Immunological tests, as well as hepatitis and HIV tests showed negative results. However, secondary syphilis was diagnosed. In discordance with the PE diagnosis, urinalysis showed glomerular microhematuria with cellular casts. Proteinuria and hypertension did not remit after delivery, which was made via caesarean section, due to uncontrolled hypertension, at an estimated gestational age of 29 weeks. A male baby, weighing 1.1 kg (6.5 centile) was born. The baby was hospitalized in the neonatal intensive care unit, where he developed subependymal hemorrhage and thrombocytopenia, and neonatal syphilis was diagnosed. The mother underwent a kidney biopsy one week after delivery, leading to the diagnosis of IgA-dominant postinfectious glomerulonephritis. Mother and child were treated with support and antibiotic therapy, and were discharged in good clinical conditions four weeks later. Four months after delivery, the mother was normotensive without therapy, with normal kidney function and without hematuria or proteinuria. In conclusion, this case suggests that IgA-dominant postinfectious glomerulonephritis should be added to the spectrum of syphilis-associated glomerulonephritides, and underlines the need for a careful differential diagnosis with CKD in all cases of presumed PE. While diagnosis relies on kidney biopsy, urinary sediment, a simple and inexpensive test, can be the first step in distinguishing PE from other nephropathies.

Sticky Platelet Syndrome: An Unrecognized Cause of Acute Thrombosis and Graft Loss.

INTRODUCTION: Sticky platelet syndrome (SPS) is a prothrombotic disease that is not well recognized and difficult to diagnose. CASE REPORT: We present a case of a 49-year-old diabetic woman on ambulatory peritoneal dialysis therapy who underwent a kidney transplant from living-related donor. The donor was her sister with whom she shared one haplotype and absence of donor specific antibodies. The posttransplant evolution was torpid, developing progressive deterioration, which made us suspect a failure in the graft. Doppler ultrasound reported renal vein thrombosis and hypoperfusion of the renal artery. Without clinical improvement, she required a reintervention that ended in graftectomy, in which the histopathological report showed negative C4d with medullary and cortical infarction. Hematological studies were negative for antibodies against phospholipids, with correct levels of proteins C and S and antithrombin. Platelet aggregometry studies were carried out, which were compatible with SPS. CONCLUSIONS: Recognition of SPS in pretransplant studies is difficult if there is no history of previous thrombotic events. However, we must consider this entity in cases of acute thrombosis and loss of the graft of uncertain origin.

Assessment of urinary TWEAK levels in Mexican patients with untreated lupus nephritis: An exploratory study / Evaluación de los niveles urinarios de TWEAK en pacientes mexicanos con nefritis lúpica sin tratamiento farmacológico: Estudio exploratorio

Objectives: Urinary levels of TWEAK (uTWEAK) may be correlated with the degree of lupus nephritis (LN) activity. Our objective was to determine the sensitivity and specificity of uTWEAK in Mexican patients with untreated active lupus nephritis. Methods: An exploratory study was performed; four groups of patients were analyzed as follows: 1) patients with systemic lupus erythematosus (SLE) without renal activity (SLE-LN), 2) patients with SLE with renal activity (SLE+LN), 3) patients with other types of glomerulopathy (glomerulonephritis, GMN), 4) and healthy patients (controls). Results: In all, 44 patients, with an average age of 35.9±11.5 years, were evaluated. uTWEAK levels were higher in patients with SLE+LN compared with patients in the other groups: SLE+LN 12.88±8.33, SLE-LN 3.12±2.31, GMN 4.36±2.31 and controls 2.41±1.94pg/mg Cr (p=0.007). A total of 72.7% of the cases had renal activity index scores above 12, and 90.9% of the cases had scores of chronicity below 6 points. Receiver Operating Characteristic (ROC) curve analysis revealed that uTWEAK levels above 4.91pg/mg Cr had a sensitivity of 81% and a specificity of 75% for the diagnosis of renal activity due to lupus, with an area under the curve of 0.876 (95% CI: 0.75-0.99). However, no significant correlation was observed between the levels of uTWEAK and the histological findings specific to the activity and chronicity associated with SLE. Conclusions: Our study revealed that uTWEAK can adequately distinguish renal activity due to lupus, but cannot predict the degree of histological activity in Mexican patients with active lupus nephropathy (AU)

Objetivos: Los niveles urinarios de TWEAK (uTWEAK) pueden correlacionarse con el grado de actividad de nefritis lúpica (NL). Nuestro objetivo fue determinar la sensibilidad y especificidad de los uTWEAK en pacientes mexicanos con NL activa sin tratamiento farmacológico previo. Metodología: Se realizó un estudio exploratorio en el que se incluyeron 4 grupos de pacientes: 1) pacientes con lupus eritematoso sistémico sin actividad renal (LES-NL); 2) pacientes con lupus eritematoso sistémico con actividad renal (LES+NL); 3) pacientes con otras glomerulopatías y 4) controles sanos. Resultados: La edad promedio de los 44 pacientes fue de 35,9±11,5 años. Los uTWEAK fueron más elevados en pacientes con LES+NL comparados con los otros grupos: LES+NL (12,88±8,33), LES-NL (3,12±2,31), otras glomerulopatías (4,36±2,31) y grupo control (2,41±1,94pg/mgCr) (p=0,007). En el 72,7% de los casos se observó un índice de actividad renal mayor a 12 puntos y en el 90,9% de los casos los índices de cronicidad estaban por debajo de 6 puntos. La curva ROC reveló que los niveles urinarios por encima de 4,91pg/mg Cr tienen sensibilidad del 81% y especificidad del 75% para el diagnóstico de actividad renal secundaria a lupus, con área debajo de la curva de 0,876 (IC 95%: 0,75-0,99). Sin embargo, no se observó correlación significativa entre los uTWEAK y los hallazgos histológicos específicos de actividad y cronicidad asociados a LES. Conclusiones: Nuestro estudio revela que los uTWEAK pueden distinguir adecuadamente actividad renal secundaria a lupus, pero no predicen el grado de actividad histológica en pacientes mexicanos con NL activa (AU)

Classification of Acute Rejection Episodes in Kidney Transplantation: a Proposal Based on Factor Analysis.

INTRODUCTION: Kidney transplantation is considered the ideal treatment for end-stage renal disease. Acute rejection can influence graft survival. The aim of this study was to propose a classification system for acute rejection based on factor analysis. MATERIALS AND METHODS: Data were collected from kidney transplant recipients with acute rejection diagnosis based on standard histological variables, the presence of peritubular eosinophils, and immunolabeling for lysozyme and myeloperoxidase in kidney tissue. Factor analysis was employed for data reduction and generation of a new case classification, with orthogonal rotation as a strategy to simplify factors, and principal component analysis was used as an extraction method. RESULTS: Seventy-nine kidney biopsies were obtained from 74 patients. The total population was divided into humoral rejection (39.2%), cellular rejection (34.1%), and mixed acute rejection (26.7%). No significant differences were found between the three groups in clinical and biochemical variables. We extracted 4 factors using factor analysis. The 1st factor was characterized by the presence of capillaritis, plasma cells infiltration, tubulitis, and inflammation. The 2nd factor included positivity for lysozyme and myeloperoxidase, while the 3rd factor included the presence of eosinophils and glomerulitis. The 4th component consisted of the presence of C4d and endarteritis. The cases belonging to the 3rd factor showed the greatest increase in serum creatinine. The cases belonging to the 4th factor exhibited greater urinary excretion of proteins. CONCLUSIONS: This proposal of classification of acute rejection could contribute to evaluate the prognosis of kidney transplant recipients.

Afección renal confirmada mediante biopsia y pronóstico en 13 pacientes hispanos con síndrome de Sjögren primario / Biopsy-proven renal involvement and prognosis in 13 hispanic patients with primary Sjögren syndrome

Antecedentes: El objetivo de este estudio fue describir una serie de casos de 13 pacientes hispanos con síndrome de Sjögren primario (SSp) y compromiso renal confirmado mediante biopsia. Métodos: Describimos las características clínicas, séricas e histológicas, y el pronóstico de un grupo de pacientes con SSp y compromiso renal confirmado mediante biopsia, tratados en 2 unidades nefrológicas de referencia de la Ciudad de México. Resultados: Se practicó biopsia renal (BR) a 13 pacientes con SSp, durante un período de 27 años. La mediana de duración entre el diagnóstico de SSp y la BR fue de 13,9 meses. Siete pacientes (54%) tenían glomerulonefritis y 6 (46%), nefritis tubulointersticial. Todos los pacientes fueron tratados con corticosteroides y/o inmunosupresores. Ocho pacientes (62%) permanecieron estables o con mejoría de su función renal en una mediana de seguimiento de 12 meses. Conclusiones: Esta serie de casos refleja el amplio espectro del daño renal en el SSp. Observamos que en nuestra población hispana, el involucro glomerular fue la alteración más frecuente, y en particular la glomerulopatía membranosa, seguida de la enfermedad tubulointersticial. La atrofia tubular y la fibrosis intersticial fueron también hallazgos comunes en la biopsia. El tratamiento con corticosteroides u otros agentes inmunosupresores parece disminuir la progresión de la enfermedad renal (AU)

Background: The aim of this study was to describe a case series of 13 Hispanic patients with primary Sjögren syndrome (pSS) and biopsy-proven renal involvement. Methods: We describe the clinical, serological and histological characteristics as well as the prognosis in a group of patients with pSS and biopsy-proven renal involvement, treated in 2 referral nephrology units in Mexico City. Results: Thirteen patients with pSS underwent kidney biopsy (KB) over a period of 27 years. The median duration from pSS diagnosis to KB was 13.9 months. Seven patients (54%) had glomerulonephritis and 6 patients (46%) had tubulointerstitial nephritis. All patients were treated with corticosteroids and/or immunosuppressants. Eight patients (62%) remained stable or their renal function improved after a median follow-up of 12 months. Conclusions: This case series reflects the broad spectrum of renal involvement in pSS. We observed that in our Hispanic population, glomerular involvement was the most frequent abnormality, mainly membranous glomerulopathy, followed by tubulointerstitial disease. Tubular atrophy and interstitial fibrosis were also common biopsy findings. Treatment with corticosteroids or other immunosuppressive agents appear to slow renal disease progression (AU)

Thrombotic microangiopathy in patients with diabetic nephropathy is associated with low VEGF expression and end-stage renal disease
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BACKGROUND: Thrombotic microangiopathy (TMA) has been associated with diabetic nephropathy, but its pathogenesis is unknown. OBJECTIVES: To determine the role of vascular endothelial growth factor (VEGF) expression in patients with TMA and diabetes mellitus. MATERIALS AND METHODS: Retrospective cohort study, patients were divided into diabetic nephropathy patients either without thrombotic microangiopathy (DN-TMA) or with thrombotic microangiopathy (DN+TMA). VEGF levels were analyzed using immunohistochemistry. Statistical analysis was performed with SPSS 20.0 software. RESULTS: There were 36 patients included in this study with a mean age of 47.6 ± 9.3 years. The average time since the diagnosis of diabetes mellitus was 6.8 ± 4.1 years. There were 21 patients (58.3%) with DN+TMA and 15 patients (41.7%) with DN-TMA. Patients with DN+TMA had a higher systolic blood pressure (p = 0.014) and diastolic blood pressure (p < 0.001) as well as proteinuria (p = 0.006), and a lower rate of glomerular filtration at baseline (p = 0.01). VEGF assessment showed lower arteriolar and glomerular expression in patients with DN+TMA (p < 0.001). The VEGF expression levels had an inverse relationship with proteinuria (r = -0.373; p = 0.03) and were directly proportional with glomerular filtration (r = 0.712; p < 0.01). Kaplan-Meier curves showed a higher probability of end-stage renal disease in patients with DN+TMA (log-rank p < 0.012). CONCLUSION: TMA is associated with low VEGF expression and end-stage renal disease in patients with diabetic nephropathy.
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A Postmortem Study of Frontal and Temporal Gyri Thickness and Cell Number in Human Obesity.

OBJECTIVE: This study aimed to compare cortex thickness and neuronal cell density in postmortem brain tissue from people with overweight or obesity and normal weight. METHODS: The cortex thickness and neuron density of eight donors with overweight or obesity (mean = 31.6 kg/m2 ; SD = 4.35; n = 8; 6 male) and eight donors with normal weight (mean = 21.8 kg/m2 ; SD = 1.5; n = 8; 5 male) were compared. All participants were Mexican and lived in Mexico City. Randomly selected thickness measures of different cortex areas from the frontal and temporal lobes were analyzed based on high-resolution real-size photographs. A histological analysis of systematic-random fields was used to quantify the number of neurons in postmortem left and right of the first, second, and third gyri of frontal and temporal lobe brain samples. RESULTS: No statistical difference was found in cortical thickness between donors with overweight or obesity and individuals with normal weight. A smaller number of neurons was found among the donors with overweight or obesity than the donors with normal weight at different frontal and temporal areas. CONCLUSIONS: A lower density of neurons is associated with overweight or obesity. The morphological basis for structural brain changes in obesity requires further investigation.

Biopsy-proven renal involvement and prognosis in 13 hispanic patients with primary Sjögren syndrome. / Afección renal confirmada mediante biopsia y pronóstico en 13 pacientes hispanos con síndrome de Sjögren primario.

BACKGROUND: The aim of this study was to describe a case series of 13 Hispanic patients with primary Sjögren syndrome (pSS) and biopsy-proven renal involvement. METHODS: We describe the clinical, serological and histological characteristics as well as the prognosis in a group of patients with pSS and biopsy-proven renal involvement, treated in 2 referral nephrology units in Mexico City. RESULTS: Thirteen patients with pSS underwent kidney biopsy (KB) over a period of 27 years. The median duration from pSS diagnosis to KB was 13.9 months. Seven patients (54%) had glomerulonephritis and 6 patients (46%) had tubulointerstitial nephritis. All patients were treated with corticosteroids and/or immunosuppressants. Eight patients (62%) remained stable or their renal function improved after a median follow-up of 12 months. CONCLUSIONS: This case series reflects the broad spectrum of renal involvement in pSS. We observed that in our Hispanic population, glomerular involvement was the most frequent abnormality, mainly membranous glomerulopathy, followed by tubulointerstitial disease. Tubular atrophy and interstitial fibrosis were also common biopsy findings. Treatment with corticosteroids or other immunosuppressive agents appear to slow renal disease progression.

Assessment of urinary TWEAK levels in Mexican patients with untreated lupus nephritis: An exploratory study.

OBJECTIVES: Urinary levels of TWEAK (uTWEAK) may be correlated with the degree of lupus nephritis (LN) activity. Our objective was to determine the sensitivity and specificity of uTWEAK in Mexican patients with untreated active lupus nephritis. METHODS: An exploratory study was performed; four groups of patients were analyzed as follows: 1) patients with systemic lupus erythematosus (SLE) without renal activity (SLE-LN), 2) patients with SLE with renal activity (SLE+LN), 3) patients with other types of glomerulopathy (glomerulonephritis, GMN), 4) and healthy patients (controls). RESULTS: In all, 44 patients, with an average age of 35.9±11.5 years, were evaluated. uTWEAK levels were higher in patients with SLE+LN compared with patients in the other groups: SLE+LN 12.88±8.33, SLE-LN 3.12±2.31, GMN 4.36±2.31 and controls 2.41±1.94pg/mg Cr (p=0.007). A total of 72.7% of the cases had renal activity index scores above 12, and 90.9% of the cases had scores of chronicity below 6 points. Receiver Operating Characteristic (ROC) curve analysis revealed that uTWEAK levels above 4.91pg/mg Cr had a sensitivity of 81% and a specificity of 75% for the diagnosis of renal activity due to lupus, with an area under the curve of 0.876 (95% CI: 0.75-0.99). However, no significant correlation was observed between the levels of uTWEAK and the histological findings specific to the activity and chronicity associated with SLE. CONCLUSIONS: Our study revealed that uTWEAK can adequately distinguish renal activity due to lupus, but cannot predict the degree of histological activity in Mexican patients with active lupus nephropathy.