Recurrent primary hyperoxaluria type 2 leads to early post-transplant renal function loss: A case report

Abstract

Primary hyperoxaluria type 2 is a rare autosomal recessive disorder caused by glyoxylate reductase/hydroxypyruvate reductase deficiency and characterized by recurrent episodes of nephrolithiasis and nephrocalcinosis. Herein, we describe a case of primary hyperoxaluria type 2 in a 33-year-old man who failed to respond to conventional therapies; thus renal transplantation was performed. This case demonstrated that, although primary hyperoxaluria type 2 is rare, hyperoxaluria should be suspected and blood oxalate and stone component be examined in patients with recurrent episodes of nephrolithiasis, particularly in those who are unresponsive to conventional therapies. Combined liver-kidney transplant may be required as kidney transplant alone is not likely to be successful.

Keywords: primary hyperoxaluria; renal calculus; renal transplant.

Figure 1.

Results of a renal biopsy in a 33-year old allogeneic renal transplant patient on day 8 post-surgery (hematoxylin and eosin stain; magnification, ×40; scale bar, 20 µm). Glomerulosclerosis was observed in 2/9 glomeruli. There was mild proliferation of mesangial cells and matrix. Mild vacuolation was observed in renal tubule epithelial cells (indicated by the arrow), crystal-like substances were occasionally seen in the renal tubule epithelial cells (indicated by hollow arrow), and the interstitia had multifocal edema. No apparent infiltration of inflammatory cells and fibrosis was observed. Mild thickening of the arterioles and hyaline changes in the microvascular wall were noted. Based on these observations, acute nephrotoxicity due to immunosuppressive drugs was considered.

Figure 2.

Results of a protocol renal biopsy in a 33-year old allogeneic renal transplant patient on day 26 post-surgery (PAS stain; magnification, ×10; scale bar, 100 µm). Borderline lesions of the renal graft, partial glomerulosclerosis (indicated by arrow) and renal tubulitis were observed. A small amount of needle-like crystal deposition in the renal tubule epithelia and multifocal edema (indicated by hollow arrow) in the interstitia were also noted. The biopsy revealed infiltration by macrophages and mild fibrosis.

Figure 3.

Results of a protocol renal biopsy in a 33-year old allogeneic renal transplant patient on day 37 post-surgery (PAS stain; magnification, ×20; scale bar, 50 µm). Borderline lesions of the renal graft, tubulitis (1+) (indicated by arrow), and crystal deposition within the renal parenchyma were observed (indicated by hollow arrow).

Figure 4.

Renal pathology of the excised renal graft from a 33-year-old allogenic renal transplant patient. (A) Gross appearance of the renal graft; the kidney measured 13×7×4.5 cm and the border between the cortex and medulla was distinct. The cortex was 0.6 cm in thickness and several gray white stones were observed in the renal pelvis. (B) Light microscopy (PAS stain; magnification, ×40; scale bar, 20 µm) revealed partial glomerulosclerosis and accumulation of blue-stained neutrophilic crystals, partially obstructing the renal tubules (indicated by arrow) and depositing in the renal interstitia. Focal sclerosis and stones were also observed (indicated by hollow arrow).