Molecular Biology, Genetic, and Epigenetic Urolithiasis Publisher



R Rahimnia RAMIN ; A Mohammadi ABDOLREZA ; A Pakdel ALIREZA ; M Gholamnejad MARYAM ; E Zemanati EHSAN ; M Khoshchehreh MAHDI
Source: Published:2024

Abstract

Urolithiasis, derived from the Greek words “ouron” meaning urine, “ouros” meaning flow, and “lithos” meaning stone, encompasses the formation of stones in the kidneys, bladder, or urinary tract. This process involves the intricate development of stones and remains a complex phenomenon not fully understood. It stands as one of the most prevalent urological disorders. Urinary stones, hardened formations occurring in the urinary tract, can lead to symptoms such as pain, hematuria, infection, or obstructed urine flow. While small stones may be asymptomatic, larger ones can cause severe pain in the flank and lower back. Often, dietary modifications and increased fluid intake can help prevent stone formation. The formation of urinary stones usually initiates in the kidneys and may enlarge in the renal pelvis or bladder. Depending on their location, stones are classified as renal, ureteral, or bladder stones. Their size can range from microscopic crystals invisible to the naked eye to stones with a diameter of 2.5 centimeters or larger. Large stones, colloquially referred to as stag horn stones due to their branching appearance resembling deer antlers, can potentially fill the entire renal pelvis and its draining cavities (calyces). Approximately 20% of the global population suffers from urinary stones, primarily composed of calcium, phosphate, oxalate, and uric acid deposits. This chemical interplay results in the accumulation of materials onto a nucleus, eventually forming stones with the potential for indefinite persistence and life-threatening secondary complications. Moreover, the management of these stones is challenging due to a high recurrence rate (50% within 10 years) and associated high costs. Regions with high prevalence include the United Kingdom, Scandinavia, Northern Australia, Central Europe, Northern India, Pakistan, and Mediterranean countries. Studies have indicated that various factors, including age, gender, industrialization, socio-economic status, diet, metabolic factors, environment, and genetics, influence the formation of urinary stones. Among these, calcium stones are the most common, constituting over 80% of cases. These stones typically originate from mixed chemical substances, including calcium oxalate and calcium phosphate. Additionally, stones may contain crystalline and colloidal components. Uric acid stones comprise 4.5%-23% of cases, while a small percentage consists of magnesium ammonium phosphate stones, struvite stones, cystine stones, guaiazuline stones, and other miscellaneous stones. The prevalence of kidney stones has significantly increased in recent decades, affecting over 15% of men and over 5% of women. Unfortunately, kidney stones often recur, with more than 50% experiencing a second episode within 10 years of the initial occurrence. Kidney stones are predominantly composed of calcium oxalate (65%) but may also contain calcium phosphate (approximately 10%), uric acid (about 15%), magnesium ammonium phosphate (about 10%), cystine (1%), 2,8-dihydroxyadenine (<1%), guaiazuline (<1%), or medications that are excreted, such as indinavir (<1%). Therefore nephrolithiasis is often associated with metabolic abnormalities in urine salt concentrations or reduced urine solubility, encompassing hypercalciuria, hyperoxaluria, hypocitraturia, cystinuria, low urine volume, and defects in urine acidification. © 2024 Elsevier B.V., All rights reserved.