NGAL as an Early Biomarker of Kidney Disease in Joubert Syndrome: Three Brothers Compared

Figures & data

Table 1. Laboratory and instrumental assessment of renal function.

	Patient 1 P.A.	Patient 2 P.S.	Patient 3 P.E.	Healthy subjects (n = 10)
Creatinine (mg/dL) T1	0.6	0.8	1.4	–
Creatinine (mg/dL) T2	0.9	0.8	2.5	0.6 ± 0.2
BUN (mg/dL) T1	19	15	20	–
BUN (mg/dL) T2	57	31	85	14 ± 7
Urine osmolality (mOsm/kg)	300	320	280	700 ± 180
Urine-specific gravity (g/mL)	1008	1008	1008	1018 ± 2
GFR T1	114	103	61	–
GFR T2	80	110	30	116 ± 20
Scintigraphy GFR (mL/min/1.73sm)	48	118	28	–
sNGAL (ng/mL)	230	150	303	45 ± 12
uNGAL (ng/mL)	110	87	197	14 ± 8

Notes: BUN, blood urea nitrogen; NGAL, neutrophil gelatinase-associated lipocalin; GFR, glomerular filtration rate; ^99mTc-DTPA, technetium-labeled diethylene-triamine-pentaacetate; T1, time of diagnosis; T2, time of the end of the follow-up (7 years).

GFR was evaluated using the Cockcroft–Gault or Schwartz formula, according to age. Renal scintigraphy was performed according to Gates’ method and infusing ^99mTc-DTPA.

Figure 1. sNGAL, uNGAL, and GFR in patients studied. It can be seen that there is a different renal impairment, given the three different values of GFR obtained using renal scintigraphy. The values of the NGAL present a different trend in the three cases and reflect, in inverse way, the renal injury. In fact, P.E. has the highest values of NGAL, due to the most severe renal impairment evidenced by the lower value of GFR.

Note: NGAL, neutrophil gelatinase-associated lipocalin; GFR, glomerular filtration rate.

Figure 2. JBTS, tubular damage, and NGAL. The gene products associated with Joubert syndrome are known to localize to primary cilium. Its disruption leads to cystic kidney disease. The increase in NGAL values may express the degree of subclinical tubular impairment, thus representing an earlier measurable index of renal suffering.

Note: JBTS, Joubert syndrome; NGAL, neutrophil gelatinase-associated lipocalin.