“Jogger’s Nephritis” After Pilgrimage

Dear Editor,

A 42-year-old lady, nondiabetic and normotensive, presented with complaints of painless, red-colored urine of 3 days duration. She had been on a pilgrimage to Tirumala. She had walked from her village, about 270 km away, with her family. After that, she took steps to Tirumala, another 16.9 km. There was no history of decreased urine output, dysuria, frothy urine, or pyuria. She had no history of non-steroidal anti-inflammatory drugs intake.

Clinical examination revealed blood pressure of 110/70 mm Hg, and systemic examination was normal except for tenderness of the lower limbs. A diagnostic algorithm was followed to exclude all causes of hematuria; urine examination showed the presence of trace albumin and 8–10/hpf red blood cells (RBCs). The RBCs were isomorphic, which was confirmed with phase contrast microscopy. Other investigations revealed the following: serum creatinine: 1.0 mg/dL; serum potassium: 4.8 meq/L; serum bilirubin: 0.4 mg/dL; lactate dehydrogenase: 105 IU/L; C3: 209.15 mg/dL; C4: 33.75 mg/dL; ASO titer: 83.57 IU/mL; serum myoglobin: 36 ng/mL; urine myoglobin: negative; and 24-hour urine protein: 328 mg. Ultrasound of the abdomen revealed right kidney: 9.3 × 4.1 cm and left kidney: 9.4 × 4.2 cm; no calculi, Doppler of renal arteries and veins did not reveal nutcracker syndrome. Her renal biopsy, including electron microscopy, was normal. After 96 hours of admission, the urine color changed from reddish brown to light red and pale yellow. The patient was discharged, and in the subsequent follow-up, there were no RBCs in the urine. It was hypothesized that the hematuria could be due to her long walk.

Hematuria in runners was first reported in the 18th century by Italian physician Bernardini Ramazzini,¹ who was later named “athletic pseudo-nephritis.”² The pathogenesis of hematuria is complex and multifactorial. The mechanisms proposed are as follows: (a) Renal vasoconstriction and ischemia due to preferential shunting of blood to the exercising muscles;³ (b) “Foot strike hemolysis,” or trauma to the RBCs circulating through the sole;⁴ (c) Long-distance running is known to cause trauma to the bladder, possibly due to repeated impacts of the flaccid wall of the bladder against the bladder base.⁵