Tc-99m diethylenetriamine pentaacetic acid (DTPA) renal function reserve estimation: is it a reliable predictive tool for assessment of preclinical renal involvement in scleroderma patients?

Abstract

Prognosis of systemic sclerosis (SSc) depends on internal organ involvement. We assessed the value of renal function reserve (RFR) for the detection of preclinical nephropathy in scleroderma. Thirty SSc patients with normal serum creatinine and 30 healthy controls were included. Medsger disease severity score, glomerular filtration rate (GFR), and microalbuminuria were measured. Tc-99m DTPA was utilized for GFR measurement at baseline and after oral protein overload (stimulated GFR). RFR was calculated as the percentile increase of stimulated GFR. SSc patients had lower means of baseline GFR (P=0.001), stimulated GFR (P=0.004), RFR (P=0.046), and higher microalbuminuria (P=0.009) than controls. According to baseline GFR, SSc patients showed three categories-normal baseline GFR (n=12), hyperfiltration GFR (n=3), and reduced baseline GFR (n=15). In the former category, RFR was normal in 6/12 patients and abnormal in the remainders (50%). Hyperfiltration patients and those with reduced baseline GFR showed abnormal RFR. A statistically significant negative association was found between microalbuminuria versus stimulated GFR and RFR (r= -0.5, P=0.007 and r= -0.45, P=0.013, respectively). The majority of SSc patients with abnormal RFR had disease duration of ≥48 months (60% vs. 20%, P=0.008). All SSc patients with pulmonary hypertension had abnormal RFR, while reduced baseline GFR was noted in only 60%. A significant negative correlation was found between reduced baseline GFR and cumulative dose of corticosteroids in SSc patients (r= -0.4, P=0.022). RFR estimation could be a useful predictive marker for preclinical renal involvement in SSc patients so that early prophylactic measures and therapy modifications could be considered.

Kidney involvement in systemic sclerosis: From pathogenesis to treatment

“…The 99 m-Tc-DTPA scintigraphy also showed 80% abnormality of RFR in 30 SSc patients without renal involvement and regardless creatinine clearance levels, thus leading to the possibility of diagnosing preclinical renal involvement also in case of normal serum creatinine (58). This is in line with previous results from Livi et al (59) who showed that RFR was significantly reduced in SSc patients, in particular if they already presented arterial hypertension and reduced basal GFR.…”

Arterial hypertension in systemic sclerosis

“…AH is commonly feared Ewa Wielosz, Magdalena Dryglewska, Anna Górak, Ewa Łyś, Maria Majdan in SSc because it often heralds renal impairment. Renal involvement is observed in 60-80% of patients with SSc, while clinically based kidney symptoms in 10-40% [7]. In the majority of cases, chronic renal involvement is found to develop slowly over the course of years, triggering moderate often clinically unapparent renal function loss in 50% of the affected patients [8].…”

Influence of antiphospholipid antibody positivity on glomerular filtration rate markers in a group of systemic sclerosis patients – a 24-month observation

“…The dominant component of SSc pathophysiology is vascular damage, which can occur early in the course of the disease and affect different internal organs mainly the lung, heart and kidney. Renal involvement is observed in 60-80% of patients with SSc, while clinically based kidney symptoms in 10-40% [ 1 , 2 ]. In the majority of cases, chronic renal involvement is found, which develops slowly over the years and leads to moderate renal function loss, often clinically unapparent, in 50% of the affected [ 2 ].…”

“…Renal involvement is observed in 60-80% of patients with SSc, while clinically based kidney symptoms in 10-40% [ 1 , 2 ]. In the majority of cases, chronic renal involvement is found, which develops slowly over the years and leads to moderate renal function loss, often clinically unapparent, in 50% of the affected [ 2 ]. Apart from chronic kidney disease (CKD) with slow deterioration of the glomerular filtration rate (GFR), the other forms of kidney involvement in SSc are: scleroderma renal crisis (SRC), which affects about 10% of SSc patients, normotensive SRC, microalbuminuria, proteinuria and rather rare vasculitis [ 3 , 4 ].…”