Approach to Persistent Microscopic Hematuria in Children

Persistent isolated microscopic hematuria is relatively common in pediatric practice, affecting around 0.25% of children. Isolated microscopic hematuria can be caused by a myriad of potentially benign or serious causes, including urologic issues; kidney stones; glomerular diseases, including disorders of the glomerular basement membrane; hematologic abnormalities; and others. The challenge for the pediatrician or pediatric nephrologist is to distinguish children with potentially progressive forms of kidney disease versus other causes while minimizing cost and inconvenience for the child and family. This manuscript will review the multiple potential causes of microscopic hematuria and provide a framework for the initial evaluation and monitoring of such patients.

P1686MULTI-NATIONAL SURVEY AMONG NEPHROLOGISTS AND TRANSPLANT SURGEONS ABOUT THE SUITABILITY AND ACCEPTANCE OF MARGINAL LIVE KIDNEY DONORS WITH MICROSCOPIC HEMATURIA

Background and Aims Potential kidney donors with isolated hematuria are often excluded from donating although there is a wide controversy about the definition and threshold of investigations or exclusion form donation. Many centers use the cut off of > 3 RBC in men and > 5 RBC in women. Some centers consider positive dipstick on urinalysis as the definition of microscopic hematuria. Kidney biopsy in these donors can be borderline and inconclusive. We conducted a short survey about the suitability of these marginal living kidney donors with microscopic hematuria. Method This is a cross-sectional survey of nephrologists and transplant surgeons (TS) about suitability and acceptance of marginal live kidney donors with isolated microscopic hematuria. The question was about a 35-yr. old man non-smoker with isolated microscopic hematuria (4 RBC on repeated UA and trace hematuria on dipstick) and negative imaging. The survey was mainly distributed through American Society of Transplantation, American Society of Transplant Surgeons and European Renal Association-European Dialysis and Transplant Association. In-training nephrologists or transplant surgeons were excluded. Results A total of (n= 122 from 22 countries, 80% nephrologists and 20% TS) responded to the survey. Most respondents were experienced in donor evaluation (72% of physicians have over 6 years’ experience and 68.5% of them perform donors’ evaluation on weekly or monthly bases). Interestingly, at this low level of microscopic hematuria (4 RBC on repeated UA and trace hematuria on dipstick) only very limited number of respondents (7.5%) would allow donation without further work up. Instead, most respondents (n= 75, 63%) would ask for kidney biopsy prior to taking further steps. Many physicians (n=35, 29%) choose to ask for an alternative donor to avoid the hassle of kidney biopsy which may not change the management. There was no difference in acceptance rate for donors between TS and nephrologists (7.2% versus 8.3% respectively, p=NS), requesting kidney biopsy (63.9% vs. 62.5%) or in declining these donors (28.8% versus 29.1%, p=NS). Conclusion Young kidney donors with persistent isolated microscopic hematuria (even at mild degree) require further evaluation with kidney biopsy before donation. However up to one third of the nephrologist and transplant surgeon will ask for an alternative donor to avoid the hassle of kidney biopsy which can be borderline or inconclusive.

Hematuria

Key Points The most common cause of hematuria overall is UTI. The most common cause of asymptomatic isolated microscopic hematuria is benign transient hematuria. Before further evaluation, repeating the urinalysis at least once is prudent, and asymptomatic school-aged children may be followed for 2 or more years before further work-up. Macroscopic hematuria is a common sign of glomerular or urologic disease, warranting renal ultrasonography and further evaluation as indicated.

Etiologies of asymptomatic microscopic hematuria in children – systematic review of 1092 subjects

Asymptomatic microscopic hematuria is common in children. No systematic review providing an evidence based approach for the differential diagnosis of these children has been performed.Multiple data bases were search. The PRISMA criteria were followed. Data regarding the etiology of the hematuria were extracted using a standardized extraction tool. Seven studies encompassing 1092 children (857 with isolated microscopic hematuria and 235 with combined microscopic hematuria and proteinuria), comprise this review. A total 42.4% of isolated microscopic and 81.3% of microscopic hematuria and proteinuria subjects had identified etiologies. Thin basement membrane nephritis (15.2%), IgA nephropathy (10.4%), and hypercalciuria without nephrolithiasis (7.7%), were the most common etiologies among children with isolated microscopic hematuria. IgA nephropathy (44.3%), thin basement membrane disease (12.8%), and mesangial proliferative glomerulosclerosis (8.9%) were the most common etiologies among children with combined microscopic hematuria and proteinuria.The present study provides an evidenced based resource, based on a systematic review, for the differential diagnosis of asymptomatic hematuria in children. Additionally, these observations suggest that children with isolated microscopic hematuria should be followed for persistence of hematuria or the development of proteinuria. Children with combined microscopic hematuria and proteinuria should be comprehensively evaluated.