Clinical implications of primary "occult" vesicoureteral reflux in male children

OBJECTIVES

To compare characteristics and outcomes of vesicoureteral reflux (VUR) detected solely on isotopic cystography (IC) ("occult" VUR) with voiding cystourethrography (VCUG)-detected VUR.

MATERIALS AND METHODS

Between 2015 and 2020, we retrospectively enrolled all male children first undergoing VCUG and, if negative, IC in the same session. Kidney injury (KI) was defined by abnormal estimated glomerular filtration rate and/or blood pressure and/or proteinuria.

RESULTS

We enrolled 421 males with a median age of 3 months and a follow-up of 5.3 years. None exhibited KI initially, but 10% of those with VUR developed KI during follow-up. Two hundred and twenty-two patients (52.7%) did not show VUR, 152 (36.1%) had VCUG-diagnosed VUR, and 47 (11.2%) had occult VUR. Therefore, 47/199 patients (23.6%) with VUR had occult VUR. Among these, 34/47 (72.3%) had dilated VUR, and 22/47 (46.8%) exhibited split renal function < 45% and/or scar (scintigraphic damage). Compared to patients with occult VUR, those with VCUG-diagnosed VUR showed a similar prevalence of febrile urinary tract infection (fUTI) before and after VUR diagnostics and KI at the last follow-up but a higher prevalence of dilated VUR, of scintigraphic damage, and underwent surgery more frequently. At multiple logistic regression analysis, patients with VCUG-diagnosed VUR presented an increased risk of fUTI either before or after VUR diagnosis and of KI, while patients with occult VUR presented an increased risk of fUTI before (and among patients with dilated VUR also after) VUR diagnosis and of KI.

CONCLUSION

Occult VUR affects 23.6% of male children with VUR with a non-negligible risk of VUR-associated KI and fUTI. IC could select, among males with recurrent fUTIs and negative VCUG, those requiring surgery for a possible dilated occult VUR.

CLINICAL RELEVANCE STATEMENT

Vesicoureteral reflux may be overlooked in 25% of boys during VCUG, yet they are at risk of fUTIs and KI. In case of recurrent infections post-negative cystourethrography, IC could detect occult reflux, guiding surgical intervention.

Rare PHEX intron variant causes complete and severe phenotype in a family with hypophosphatemic rickets: a case report

OBJECTIVES

Lower limb deformities in children need careful orthopedic evaluation to distinguish physiological forms from pathological ones. X-linked hypophosphatemia (XLH) is a rare hereditary condition caused by PHEX gene mutations where tibial varum can be the first sign.

CASE PRESENTATION

We report a family presenting with severe tibial varum, harbouring a rare PHEX intron mutation, c.1586+6T>C. This is the first clinical description available in literature for this variant. Despite the previous prediction of a mild phenotype in functional study, our patients showed important bone deformities, rickets and impaired growth since infancy followed by severe bone pain, hearing loss and reduced life quality in adulthood. Burosumab therapy improved biochemical and radiological findings in children and ameliorated quality of life in adults.

CONCLUSIONS

This case demonstrated c.1586+6T>C causes a severe XLH phenotype, responsive to Burosumab. Familial genetic screening, enlarged to intronic region analysis, when XLH is suspected, allows precocious diagnosis to start timely the appropriate treatment.

Hematuria at dipstick on first versus second morning voiding: A screening for patients with persistent isolated hematuria?

BACKGROUND

In our clinical practice we observed that -differently from patients with defined glomerulopathies- children with persistent isolated microscopic hematuria (PImH) usually shows at dipstick on first compared with second morning voiding lower degree of hematuria. We hypothesized that comparison of hematuria degree between first and second morning voiding (dipstick comparison test) could help in selection of patients needing of specific investigations. In this study, we aimed preliminarily validating our hypothesis.

METHODS

To define the risk of active glomerulopathies we used patients with defined glomerulopathies as cases. We prospectively enrolled 103 children during a one-year period. Sixty-nine of them had PImH, 16 microscopic/macroscopic hematuria (mMH), and 18 defined glomerulopathies. Inclusion criteria were: 1) persistent microscopic hematuria (≥1+ at dipstick) with or without defined glomerulopathy and/or previous episodes of macroscopic hematuria; 2) for the patients without defined glomerulopathy, having made regular biannual follow-up visits for at least 2 years in our department; 3) normal renal function and blood pressure at enrollment visit. We compared hematuria degree between first and second morning voiding. Possible findings were absence (NH), less degree (LH), similar degree (SH), and higher degree (HH) of hematuria in the first compared with second voiding.

RESULTS

At dipstick comparison test, 27.2% of patients presented NH, 44.7% LH, 28.1% SH, and none HH. NH showed specificity and PPV of 100% and significant area under receiver operating characteristic curve (AUROC = 0.66; 95%CI:0.55-0.78; p = 0.03) for absence of defined glomerulopathies. LH showed better sensitivity (76.9% Vs 33%) and NPV (78.9% Vs 24%) and lower specificity (88.2% Vs 100%) and PPV (87.0% Vs 100%) than NH for absence of defined glomerulopathies. Moreover, the LH showed a non-significant AUROC curve for presence of defined glomerulopathies. SH showed specificity of 80%, NPV of 91.9% and significant AUROC curve for presence of defined glomerulopathies (0.67; 95%CI:0.55-0.80; p = 0.009). The ROC curve analysis examining the delta of hematuria degree comparing first with second morning urine voiding showed a significant AUROC curve (AUROC = 0.78; 95%CI,0.68-0.89; p = 0.0002) with delta ≤ 1 showing the best sensitivity (80%) and specificity (66.7%) for defined glomerulopathies. None of the patients with defined glomerulopathies presented NH. Having SH presented relative risk for defined glomerulopathy of 5.1 (95%CI:1.9-13.6; p = 0.0007). Conversely, taken together NH and LH the RR was 0.2 (95%CI 0.1-0.5; p = 0.0007).

INTERPRETATIONS

The dipstick on the first urine voiding underestimates the hematuria in about 70% of patients. The dipstick comparison test might easily screen patients with PImH and mMH needing of further investigations and treatment.