Post-streptococcal acute glomerulonephritis in children: Association between proteinuria levels and renal outcomes

Table 1 Age and sex distribution of the study population

Age in years	Male	Female
Birth-5	5 (11.4)	2 (4.5)
5-10	9 (20.4)	9 (20.4)
> 10	13 (29.5)	6 (13.6)

Data are n (%).

Table 2 Association between the degree of proteinuria and hypertension in children with post-streptococcal acute glomerular nephritis

Degree of proteinuria	Blood pressure centile			Total
	> 95th	90th-95th	< 90th
< 2+	7 (20.6)	1 (2.9)	3 (8.8)	11 (32.3)
≥ 2+	18 (52.9)	1 (2.9)	4 (11.8)	23 (67.6)
Total	25 (73.5)	2 (5.9)	7 (20.6)	34 (100)

Data are n (%).

Table 3 Association between the degree of proteinuria and serum creatinine in children with post-streptococcal acute glomerular nephritis

Degree of proteinuria	Serum creatinine in µmol/L		Total
	< 100	≥ 100
< 2+	12 (30.8)	1 (2.6)	13 (33.3)
≥ 2+	12 (30.8)	14 (35.9)	26 (66.7)
Total	24 (61.5)	15 (38.5)	39 (100)

Data are n (%).

Table 4 Association between the degree of proteinuria and injury to kidney according to pRIFLE criteria in children with post-streptococcal acute glomerular nephritis

Degree of proteinuria		Estimated creatinine clearance		Total
		< 50%	> 50%
< 2+		1 (2.5)	12 (30.8)	13 (33.3)
≥ 2+		7 (18)	19 (48.7)	26 (66.7)
Total		8 (20.5)	31 (79.5)	39 (100)

Data are n (%).

Table 5 Renal biopsy findings in children with persistent proteinuria ≥ 2+ for 2 weeks and highest recorded serum creatinine > 100 μmol/L

Age	Macroscopic findings	Microscopic findings	Conclusion
12 years	Two pieces of tissue measuring 5 mm and 6 mm	Glomeruli-Twelve glomeruli were seen. All glomeruli showed mesangial proliferation and increased matrix. Mesangial hyperplasia was seen with increased intimal proliferation and obliteration of lumina. Three glomeruli showed cellular crescents. Basement membrane was not thickened. Tubules-No tubular distortion was noted. Interstitium-No inflammation was seen. Vessels-Vessels were not seen	Acute diffuse proliferative glomerulonephritis with cellular crescent formation
8 years 3 months	Two cores measuring 4 mm × 1 mm × 1 mm, 3 mm × 1 mm × 1 mm	Glomeruli-Ten glomeruli were seen. Increased mesangial cell hyperplasia and matrix were noted. No wire loops/necrosis was seen. Basement membrane was not thickened. Neutrophil infiltration was present. Crescents were seen in two glomeruli. No chronic changes were noted. Tubules-Tubules showed mild dilatation and flattening. There was no evidence of tubulitis. Amorphous material was seen in the lumen of tubules. Some degree of tubular damage was evident. Calcification was not seen. Interstitium-Mild inflammation was present. Vessels-Vessels were normal	Acute diffuse proliferative glomerulonephritis with cellular crescent formation. Mild degree of tubular damage was seen
6 years 3 months	Four cores measuring 15 mm, 10 mm, 4 mm, and 3 mm in length and 1 mm in diameter	Glomeruli-Sixteen viable glomeruli were seen. They showed diffuse mesangial proliferation. There was inflammation with neutrophil infiltration. Three glomeruli showed endocapillary proliferation with early crescent formation. Cellular crescents were seen in three glomeruli. No necrosis or sclerosis was present. Basement membrane was not thickened. Tubules-The tubules were unremarkable. No tubulitis or evidence of acute tubular necrosis was present. Interstitium: The interstitium was unremarkable. Vessels: Vessels were not seen	Acute diffuse proliferative glomerulonephritis with crescent formation
8 years	Three cores measuring 15 mm × 1 mm × 1 mm and 5 mm × 1 mm × 1 mm	Glomeruli-Twelve viable glomeruli were seen. All showed varying degree of intimal proliferation and obliteration of lumina, mesangial hyperplasia with increased of intimal proliferation, and obliteration of lumina. Early crescents formation seen in four glomeruli. Tubules: Morphology was unremarkable. Interstitium: Focal infiltrate of lymphocytes, neutrophils and oedema were seen	Proliferative glomerulonephritis with crescents formation
5 years 6 months	Two cores measuring 18 mm and 14 mm in length and 2 mm in diameter	Glomeruli-Eighteen viable glomeruli were seen in two cores. Varying degree of mesangial hypercellularity and increased matrix were evident. Three glomeruli showed endothelial hyperplasia with obliteration of lumen and infiltration by neutrophils. No sclerosis or crescents was seen. Tubules-No Tubular distortion was seen. Interstitium-No inflammation was present. Vessels-Unremarkable	Proliferative glomerulonephritis suggestive of postinfectious glomerulonephritis
12 years 4 months	Two cores measuring 8 mm and 4 mm	Glomeruli-Sixteen viable glomeruli were seen. They showed diffuse mesangial proliferation. There was inflammation with neutrophil infiltration. Three glomeruli showed endocapillary proliferation. No crescents or sclerosis was seen. Tubules-The tubule showed dilatation, vacuolation and flattening. There was evidence of tubulitis. Amorphous material was seen in the lumen of tubules. Severe degree of tubular damage was present. Interstitium-Focal infiltrate of lymphocytes was seen. Blood Vessels-Unremarkable	Acute diffuse glomerulonephritis with severe tubular damage
11 years 10 months	Two cores measuring 8 mm × 1 mm × 1 mm and 4 mm × 1 mm × 1 mm	Glomeruli-Fourteen viable glomeruli were seen. They showed mild diffuse mesangial proliferation with neutrophil infiltrates. No evidence of crescent formation, hypercellularity, or karyorrexhis was seen. Tubules-Tubules were histologically unremarkable. Interstitium-No evidence of inflammation or fibrosis was seen. Blood vessels-unremarkable	Acute diffuse proliferative glomerulonephritis
7 years 8 months	Two pieces of tissue measuring 6 mm and 7 mm	Glomeruli-Total of 10 Glomeruli were seen. All glomeruli showed mesangial proliferation, and increased matrix infiltrated with neutrophils. Mesangial hyperplasia with increased intimal proliferation and obliteration of lumina were seen. Three glomeruli showed endocapillary proliferation with early crescents formation. Three glomeruli showed cellular crescents. Basement membrane was not thickened. Tubules- Mild tubular distortion was seen. Interstitium-Focal infiltrate of lymphocytes was seen. Vessels-Vessels were not seen	Acute diffuse proliferative glomerulonephritis with > 50% cellular crescent formation (rapidly progressive glomerulonephritis)
5 years 3 months	Two cores measuring 14 mm and 10 mm in length and 1 mm in diameter	Glomeruli-Fourteen viable glomeruli were seen. They showed diffuse mesangial proliferation. There was neutrophil infiltration. Three glomeruli showed endocapillary proliferation with early crescent formation. No necrosis or sclerosis was seen. Basement membrane was not thickened. Tubules-The tubules were unremarkable. Interstitium-The interstitium was unremarkable. Vessels-Unremarkable	Acute diffuse proliferative glomerulonephritis with early crescent formation
7 years 6 months	Two cores measuring 12 mm and 10 mm in length and 2 mm in diameter	Glomeruli-Twenty viable glomeruli were seen in two cores. Varying degree of mesangial hypercellularity and increased matrix were seen. No sclerosis or crescents was seen. Mild neutrophil infiltrates were present. Basement membrane was normal. Tubules-No Tubular distortion was seen. Interstitium-No inflammation was present. Vessels-unremarkable	Proliferative glomerular nephritis. The findings were in favour of postinfectious glomerulonephritis