Renal biopsy findings in new-onset systemic lupus erythematosus with clinical renal disease

Urinary Sediments as Predictors of the Histopathology of Lupus Nephritis

Lupus nephritis (LN) is a major risk factor for morbidity and mortality in systemic lupus erythematosus (SLE). Urinalysis has an invaluable role in the diagnosis of various renal and urological diseases. Examinations of the urinary sediment using phase contrast microscopy (PCM) may add more information to help earlier diagnoses of LN. This cross-sectional study aimed to assess the possible role of the components of urinary sediment examined using PCM in discriminating the proliferative classes of LN (III and IV ± V) from the non-proliferative classes (I, II, and V), and to detect the correlation between the components of urinary sediment and indices of both activity and chronicity found by the renal biopsy. The study was conducted on 40 SLE patients for whom a renal biopsy was indicated. Clinical, demographic, and laboratory data and the results of the histopathological renal biopsy were collected. The morning before the renal biopsy; urine samples were collected from every patient and examined by PCM. Receiver operating characteristic curves were used to detect the area under the curve to predict proliferative LN. The correlations of counts of leukocytes, erythrocytes, all dysmorphic erythrocytes, acanthocytes, and stomatocytes with the indices of activity and chronicity were significant (activity: P = 0.027, P = 0.015, P = 0.033, P = 0.040, and P <0.001*; chronicity: P = 0.035, P = 0.009, P = 0.027, P = 0.010, and P <0.001, respectively). For patients with SLE, urinary sediment examinations can suggest a renal biopsy for the histopathology of LN.

Renal Tubular Acidosis in Patients with Systemic Lupus Erythematosus

OBJECTIVE

Renal tubular acidosis (RTA) is a clinical manifestation that occurs with insufficiency in restoring bicarbonate or disruption in hydrogen ion elimination as a result of a disruption in tubulus functions, causing normal anion gap-opening metabolic acidosis. In the present study, we aimed to investigate the prevalence of RTA in the largest systemic lupus erythematosus (SLE) patient population to date.

MATERIALS AND METHODS

SLE patients, who were followed up in 2 different healthcare centers, were included. Patients with metabolic acidosis (pH <7.35 and HCO3 <22 mEq/L) in venous blood gas analysis were determined. The serum and urine anion GAP of these patients were estimated, and the urine pH was assessed. RTA presence was evaluated as metabolic acidosis with a normal serum anion gap and a positive urine anion GAP.

RESULTS

A total of 108 patients were included in the present study. The mean age of the patients was 41.5 ± 1.2 and 87% were female. The SLE diagnosis duration was 75 ± 5 months. The mean creatinine value ​​was 0.6 ± 0.1 mg/dL and the mean eGFR was 111 ± 2 mL/min. According to the blood gas analysis, 18 patients (16.7% of the total) had RTA. Sixteen of these patients had type 1 RTA and 2 had type 2 RTA; type 4 RTA was not determined in any of the patients.

CONCLUSION

RTA should be considered in SLE patients even if they have normal eGFR values. This is the largest study to examine the prevalence of RTA in SLE patients in the literature.

The clinical manifestations and response to treatment in South Africans with lupus nephritis

There are varying observations on the influence of ethnicity on the clinical spectrum and response to treatment in lupus nephritis (LN). We studied a multiethnic South African LN cohort to determine the clinical manifestations, histological involvement and response to therapy. We reviewed the records of LN patients at Inkosi Albert Luthuli Central Hospital in Durban. There were 105 patients, 92.5% females and they comprised 49.1% Indians and 45.3% African Blacks. The mean age was 31.3 ± 12.5 years, and 41.5% had LN at first presentation of lupus. The most common histological classes were Class V alone in 34.9%, Class IV (± Class V) in 25.5% and Class III (±Class V) in 22.6%. The estimated glomerular filtration rate was reduced (<30 ml/min) at presentation in 15 (14.2%). Eighty-seven patients received therapy for LN. A response to induction therapy was noted in 81.6% and maintenance therapy (12 months) in 73.6%. Response to mycophenolate mofetil (MMF) was 80.4% and 68.4% during induction and maintenance therapy, respectively. There was no ethnic difference in the histological class or response to MMF but African Blacks had more severe renal disease at presentation. In conclusion, our multiethnic LN cohort shows a high prevalence of membranous LN and good response to treatment.

Correlation between Doppler parameters and renal cortical fibrosis in lupus nephritis: a preliminary observation

To assess the relationship between renal Doppler parameters and renal cortical fibrosis in lupus nephritis (LN), we retrospectively reviewed 24 patients with LN underwent both renal color Doppler sonography and renal biopsy. The angle-corrected Doppler parameters, including peak systolic velocity (PSV), end diastolic velocity (EDV) and resistive index (RI) at the main and interlobar renal arteries were measured. The Doppler parameters and PSV and EDV ratios of the interlobar artery to main renal artery were compared with histopathologic analysis of the kidney biopsy specimen. On the basis of renal cortical fibrosis, the 24 cases of LN were divided into two groups: mild (6%-25%) renal cortex fibrosis (n = 13) and moderate (26%-50%) renal cortex fibrosis (n = 11). An independent-samples two tailed t test was used to statistically analyze the differences in PSV, EDV and RI between the two groups. Receiver operating characteristic was analyzed for assessing the accuracy of interlobar artery PSV and EDV in predicting moderate renal cortical fibrosis. In our result, both PSV and EDV in moderate renal cortex fibrosis were lower than that in mild renal cortex fibrosis. There were statistically significant differences in PSV and EDV at the interlobar artery, EDV and RI at the main renal artery, and PSV and EDV ratios of the interlobar artery to main renal artery between the two groups (all p < 0.05). The area under receiver operating characteristic curves of PSV and EDV for predicting >26% renal cortical fibrosis was 0.96 and 0.90, respectively. The optimal cutoff values for differentiating >26% renal cortical fibrosis from those <25% were PSV 30 cm/s (sensitivity = 0.92; specificity = 1) and EDV 13 cm/s (sensitivity = 0.77; specificity = 1). Therefore, the values of PSV and EDV at the interlobar artery can potentially be used as hemodynamic indicators of renal cortical fibrosis, which may non-invasively assist in monitoring the progression of renal cortical fibrosis in LN, especially in patients with contraindications to renal biopsy.