Distinguishing the Signals From the Noise: Can Epidemiologic Studies Inform Our Understanding of Glomerular Disease?

Clinical and histopathological characteristics of primary focal segmental glomerulosclerosis in Turkish adults

The data regarding primary FSGS (pFSGS) from different parts of the world differ. While the prevalence of pFSGS has been increasing in Western countries like the USA, it follows an inconsistent trend in Europe and Asia and a decreasing trend in Far Eastern countries such as China in the last two decades. There are undetermined factors to explain those national and geographic discrepancies. Herein, we aimed to reveal the current prevalence with clinical and histopathological characteristics of pFSGS in Turkish adults. This study includes the biopsy-proven pFSGS patients data recorded between 2009 and 2019, obtained from the national multicenter primary glomerulonephritis registry system of the Turkish Society of Nephrology Glomerular Diseases (TSN-GOLD) database. 850 of the 3875 primer glomerulonephritis patients(21.9%) have pFSGS. The mean age is 40.5 ± 14.2 and 435 (51.2%) of patients are male. Nephrotic syndrome is the most common biopsy indication (59.2%). 32.6% of patients have hematuria, 15.2% have leukocyturia and 7.8% have both. Serum creatinine, albumin, and proteinuria are 1.0 mg/dL (IQR = 0.7-1.4) mg/dl, 3.4 ± 0.9 g/dl, 3400 mg/day(IQR, 1774-5740), respectively. Females have lower mean arterial pressure (- 2.2 mmHg), higher eGFR (+ 10.0 mL/min/1.73 m2), and BMI (+ 1.6 kg/m2) than males. Thickened basal membrane(76.6%) and mesangial proliferation (53.5%) on light microscopy are the major findings after segmental sclerosis. IgM (32.7%) and C3 (32.9%) depositions are the most common findings on immunofluorescence microscopy. IgM positivity is related to lower eGFR, serum albumin, and higher proteinuria. The prevalence of pFSGS is stable although slightly increasing in Turkish adults. The characteristics of the patients are similar to those seen in Western countries.

Prevalence and 20-year epidemiological trends of glomerular diseases in the adult Saudi population: a multicenter study

BACKGROUND

Recent international reports have shown significant changes in the incidence of different glomerular diseases.

OBJECTIVE

Examine temporal and demographic trends of biopsy-diagnosed glomerular diseases in the adult population of Saudi Arabia over the last two decades.

DESIGN

Medical record review.

SETTINGS

Four tertiary medical centers in Saudi Arabia.

PATIENTS AND METHODS

We identified all patients that underwent native kidney biopsy between 1998 and 2017.

MAIN OUTCOME MEASURES

The frequency and the disease trends in four biopsy eras (1998-2002, 2003-2007, 2008-2011, and 2012-2017) for different glomerular diseases.

SAMPLE SIZE AND CHARACTERISTICS

1070 patients, 18-65 years of age; 54.1% female.

RESULTS

Of 1760 patients who underwent native kidney biopsies, 1070 met inclusion criteria. Focal segmental glomerulosclerosis was the most common biopsy-diagnosed disease, with comparable frequencies over the four eras (23.6%, 19.8%, 24.1%, and 17.1, respectively [ P value for trend=.07]). The frequency of immunoglobulin A nephropathy increased progressively. The incidence of membranoproliferative glomerulonephritis declined significantly. Among the secondary types of glomerular diseases, systemic lupus erythematosus-associated lupus nephritis was the most common, followed by diabetic nephropathy. The prevalence of diabetic nephropathy increased from 1.4% in the first era to 10.2% in the last one.

CONCLUSIONS

Trends in biopsy-diagnosed glomerular disease have changed. While focal segmental glomerulosclerosis remains the most common glomerular disease, there has been a significant rise in the prevalence of immunoglobulin A nephropathy and diabetic nephropathy. In contrast, membranoproliferative glomerulonephritis has declined.

LIMITATIONS

Retrospective methodologies are vulnerable to lost data.

CONFLICT OF INTEREST

None.

Glomerulonephritis disease pattern at Saudi tertiary care center

OBJECTIVE

To assess changes in the pattern of glomerular diseases to help guide optimal allocation of resources, to focus future reasearch, and improve outcomes. Methods: A retrospective chart review was conducted on kidney biopsies taken between 2007 and 2016 at a single tertiary care center in Saudi Arabia (King Fahad Medical City, Riyadh) to evaluate the prevalence and pattern of glomerulonephritis (GN). Results: The most common primary GN in 102 biopsies from adult patients with a mean age of 28.9 ± 13.6 years and 40.2% female, was focal and segmental glomerulosclerosis (35.3%). Among 64 patients with systemic lupus erythematosus associated nephritis, of whom most (82.8%) were female, lupus nephritis (LN) 4 (46.9%), and (LN) 3 (32.8%) were the most common lupus nephritis classes. Conclusion: Establishing prospective GN registries from which robust diagnosis, treatment, and outcomes data can be acquired is warranted; however, registry development and maintenance are often precluded by resource limitations. Accordingly, retrospective analysis of administrative data will continue to provide important complementary information on GN epidemiology.