Glomerular and Tubulointerstitial Diseases

Higher incidence of hematuria was observed in female children with microtia

The goals of this study were to investigate the incidence and characteristics of hematuria in patients with microtia, and to clarify that more attention should be paid to renal dysfunction in patients with microtia. We conducted a retrospective cohort study of a total 9447 children diagnosed with microtia (selected as study group, 7037 children) or pigmented nevus (selected as control group, 2410 children) at the Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College from January 2009 to June 2021. All of the routine urinalysis report of these children were reviewed to assess the incidence and characteristics of hematuria in each group. No statistically significant differences were observed when analyzing the overall incidence of hematuria between the study and control groups (P > 0.05). However, after grouping by sex, the incidence of hematuria in female children with microtia was significantly higher than that in femalecontrol group and no similar results were observed in the male patients. In addition, after further grouping by age in case group, the incidence of hematuria in girls of all ages with microtia was significantly higher than that in males with microtia (age 0-10:males: Girls = 1.89%:4.14%; age 0-5: males: Girls = 1.22%:3.73%; age 6-10: males:Girls = 1.97%:4.14%,P < 0.05), while no similar results were obtained in the control group.(age 0-10:males: Girls = 1.39%:2.22%; age 0-5: males: Girls = 1.07%:1.95%; age 6-10: males: Girls = 3.38%:3.17%, P > 0.05). Higher incidence of hematuria was observed in female children with microtia.

IgG4 tubulointerstitial nephritis - An uncommon enemy!

IgG4-related disease (IgG4-RD) is an evolving entity characterized by immune mediated multisystem involvement in the form of fibro inflammatory lesions like sclerosing pancreatitis, dacryoadenitis, Reidel thyroiditis, or chronic sclerosing sialadenitis. Barely, the lesions are restricted to kidney (IgG4-RKD: IgG4-related kidney disease) involving either glomerular or extraglomerular compartment. It is challenging to identify and demands an awareness regarding the entity to reduce the number misdiagnosis and missed diagnosis. Here, we report a case of a 45-year-old woman with IgG4 tubulointerstitial nephritis (IgG4-TIN) who presented with unexplained renal dysfunction as her initial manifestation. This is the first case of IgG4-RKD reported from our tertiary care center among 1864 native renal biopsy in the last two years.

Kidney Diseases: The Age of Molecular Markers

Kidney diseases are conditions that increase the morbidity and mortality of those afflicted. Diagnosis of these conditions is based on parameters such as the glomerular filtration rate (GFR), measurement of serum and urinary creatinine levels and equations derived from these measurements (Wasung, Chawla, Madero. Clin Chim Acta 438:350-357, 2015). However, serum creatinine as a marker for measuring renal dysfunction has its limitations since it is altered in several other physiological situations, such as in patients with muscle loss, after intense physical exercise or in people on a high protein diet (Riley, Powers, Welch. Res Q Exerc Sport 52(3):339-347, 1981; Juraschek, Appel, Anderson, Miller. Am J Kidney Dis 61(4):547-554, 2013). Besides the fact that serum creatinine is a marker that indicates glomerular damage, it is necessary the discovery of new biomarkers that reflect not only glomerular damage but also tubular impairment. Recent advances in Molecular Biology have led to the generation or identification of new biomarkers for kidney diseases such as: Acute Kidney Failure (AKI), chronic kidney disease (CKD), nephritis or nephrotic syndrome. There are recent markers that have been used to aid in diagnosis and have been shown to be more sensitive and specific than classical markers, such as neutrophil gelatinase associated lipocalin (NGAL) or kidney injury molecule-1 (KIM-1) (Wasung, Chawla, Madero. Clin Chim Acta 438:350-357, 2015; George, Gounden. Adv Clin Chem 88:91-119, 2019; Han, Bailly, Abichandani, Thadhani, Bonventre. Kidney Int 62(1):237-244, 2002; Fontanilla, Han. Expert Opin Med Diagn 5(2):161-173, 2011). However, early diagnostic biomarkers are still necessary to assist the intervention and monitor of the progression of these conditions.

Clinical Approach to Diagnosing Acute and Chronic Tubulointerstitial Disease

Tubulointerstitial diseases are a relatively common cause of acute and/or chronic kidney disease. Acute tubulointerstitial nephritis (ATIN) most commonly develops in patients exposed to various medications; however, it can occur from infections, autoimmune and systemic diseases, environmental exposures, and some idiopathic causes. Chronic tubulointerstitial nephritis may develop in patients with previous ATIN or may be the initial manifestation of an autoimmune, systemic, environmental, or metabolic process. It can be challenging for clinicians to differentiate the various causes of acute and chronic kidney disease. In particular, distinguishing ATIN from other causes of acute kidney injury, such as acute tubular necrosis or a rapidly progressive glomerulonephritis, is important as treatment and prognosis are often quite different. To this end, clinicians use clinical assessment, certain laboratory data, and various imaging tests to make a diagnosis. Unfortunately, most of these tests are insufficient for this purpose. As a result, kidney biopsy is often required to accurately diagnose ATIN and guide management. For chronic tubulointerstitial nephritis, kidney biopsy is needed less often as available therapies for this entity, with a few exceptions, are limited and primarily supportive.

The use of stem cells in kidney disease

PURPOSE OF REVIEW

Acute and chronic kidney disease is a leading cause of morbidity and mortality worldwide with overall mortality rates between 50 and 80%. An acute shortage of compatible organs coupled with limited adaptability of current dialysis techniques has created a sense of urgency to investigate new alternatives, and the purpose of this review is to provide a concise overview of current stem cell-based strategies in renal repair following acute kidney injury.

RECENT FINDINGS

Bone marrow-derived mesenchymal stem cells hold therapeutic potential in repairing tubular injury, ameliorating renal function deficits, and prolonging survival in experimental models of acute kidney injury. These renoprotective effects are mediated mainly by paracrine mechanisms that act on surviving tubular cells by stimulating dedifferentiation, proliferation, migration, and eventually redifferentiation into mature epithelial cells as well as by stimulating expansion and differentiation of resident stem/progenitor cells. Mesenchymal stem cells are capable of immunosuppression as well as inducing protection against peritubular capillary changes following acute injury making them ideal for allogeneic cell therapy.

SUMMARY

Autologous transplantation of bone marrow-derived mesenchymal stem cells as well as adult renal stem/progenitor cells that can be easily harvested and expanded may be the solution to limited donor organ availability and chronic immunosuppressive therapy.