Sickle cell nephropathy is a type of nephropathy associated with sickle cell disease which causes kidney complications as a result of sickling of red blood cells in the small blood vessels. The hypertonic and relatively hypoxic environment of the renal medulla, coupled with the slow blood flow in the vasa recta, favors sickling of red blood cells, with resultant local infarction (papillary necrosis). Functional tubule defects in patients with sickle cell disease are likely the result of partial ischemic injury to the renal tubules. Also the sickle cell disease in young patients is characterized by renal hyperperfusion, glomerular hypertrophy, and glomerular hyperfiltration. Many of these individuals eventually develop a glomerulopathy leading to glomerular proteinuria (present in as many as 30%) and, in some, the nephrotic syndrome. Co-inheritance of microdeletions in the -globin gene (thalassemia) appear to protect against the development of nephropathy and are associated with lower mean arterial pressure and less protein in the urine. Mild increases in the blood levels of nitrogen and uric acid can also develop. Advanced kidney failure and high blood urea levels occur in 10% of cases. Pathologic examination reveals the typical lesion of "hyperfiltration nephropathy" namely, focal segmental glomerular sclerosis. This finding has led to the suggestion that anemia-induced hyperfiltration in childhood is the principal cause of the adult glomerulopathy. Nephron loss secondary to ischemic injury also contributes to the development of azotemia in these patients

Pathophysiology
The development of sickle cell nephropathy (SCN) typically occurs in childhood as seen in the appearance of hyperfiltration and proteinuria.
Cetirizine, sold under the brand name Zyrtec among others, is a second-generation antihistamine used to treat allergic rhinitis (hay fever), dermatitis, and urticaria (hives). It is taken by mouth. Effects generally begin within thirty minutes and last for about a day. The degree of benefit is similar to other antihistamines such as diphenhydramine.Common side effects include sleepiness, dry mouth, headache, and abdominal pain. The degree of sleepiness that occurs is generally less than with first generation antihistamines. Use in pregnancy appears safe, but use during breastfeeding is not recommended. The medication works by blocking histamine H1 receptors, mostly outside the brain.It was patented in 1981 and came into medical use in 1987. It is on the World Health Organizations List of Essential Medicines. It is available as a generic medication. In 2020, it was the 52nd most commonly prescribed medication in the United States, with more than 13 million prescriptions. Medical uses
Allergies
Cetirizines primary indication is for hay fever and other allergies. Because the symptoms of itching and redness in these conditions are caused by histamine acting on the H1 receptor, blocking those receptors temporarily relieves those symptoms.Cetirizine is also commonly prescribed to treat acute and (in particular cases) chronic urticaria, more efficiently than any other second-generation antihistamine. Available forms
Cetirizine is available over-the-counter in the US in the form of 5 and 10 mg tablets. A 20 mg strength is available by prescription only. It is also available as a 1 mg/mL syrup for oral administration by prescription.