Elevated Urinary Neutrophil Gelatinase-Associated Lipocalin Is a Biomarker for Lupus Nephritis: A Systematic Review and Meta-Analysis

Table 2

Summary of data available for meta-analysis.

Study	Cut-off point	Reference standard	TP	FP	FN	TN	Sensitivity (95% CI)	Specificity (95% CI)
Part 1: the diagnostic accuracy for uNGAL to identify LN in SLE
Brunner et al. 2006 [20]	0.6 ng/mg Cr	Biopsy	15	0	2	18	0.88 (0.64, 0.99)	1.00 (0.81, 1.00)
Pitashny et al. 2007 [21]	28 ng/mg Cr	Biopsy	10	3	9	35	0.53 (0.29, 0.76)	0.92 (0.79, 0.98)
Sharifipour et al. 2013 [27]	0.39 ng/mg Cr	Biopsy	26	14	3	9	0.90 (0.73, 0.98)	0.39 (0.20, 0.61)
Susianti et al. 2015 [32]	446.3 pg/ml	Biopsy	40	4	10	16	0.80 (0.66, 0.90)	0.80 (0.56, 0.94)
Tawfik et al. 2015 [33]	20 ng/mg Cr	Biopsy	13	2	9	11	0.59 (0.36, 0.79)	0.85 (0.55, 0.98)
Eman et al. 2015 [34]	13.2 ng/dl	Biopsy	19	0	3	22	0.86 (0.65, 0.97)	1.00 (0.85, 1.00)
El Shahawy et al. 2018 [36]	13.66 ng/ml	Biopsy	46	5	4	15	0.92 (0.81, 0.98)	0.75 (0.51, 0.91)
Gómez-Puerta et al. 2018 [37]	11.98 ng/ml	Biopsy	51	16	25	28	0.67 (0.55, 0.77)	0.64 (0.48, 0.78)
Li et al. 2019 [38]	80 ng/ml	Biopsy	53	0	1	36	0.98 (0.90, 1.00)	1.00 (0.90, 1.00)
Part 2: the diagnostic accuracy for uNGAL to identify active LN
Brunner et al. 2006 [20]	0.6 ng/mg Cr	R-SLEDAI	11	0	1	23	0.92 (0.62, 1.00)	1.00 (0.85, 1.00)
Rubinstein et al. 2010 [23]	11.7 ng/ml	R-SLEDAI	62	104	21	70	0.75 (0.64, 0.84)	0.40 (0.33, 0.48)
Rubinstein et al. 2010 [23]	11.7 ng/ml	BILAG2004	9	42	4	26	0.69 (0.39, 0.91)	0.38 (0.27, 0.51)
Kiani et al. 2012 [24]	0.3 ng/mg Cr	SLICC	13	15	51	92	0.20 (0.11, 0.32)	0.86 (0.78, 0.92)
Alharazy et al. 2013 [25]	91.25 ng/mg Cr	R-SLEDAI	42	17	5	36	0.89 (0.77, 0.97)	0.68 (0.54, 0.80)
Torres-Salido et al. 2014 [29]		R-SLEDAI	34	4	4	25	0.90 (0.75, 0.97)	0.86 (0.68, 0.96)
Maeda-Hori et al. 2014 [28]		BAI	6	7	5	46	0.55 (0.23, 0.83)	0.87 (0.75, 0.95)
Elewa et al. 2015 [31]		R-SLEDAI	11	11	5	3	0.69 (0.41, 0.89)	0.21 (0.05, 0.51)
Satirapoj et al. 2017 [35]	28.08 ng/ml	UPCR	8	18	3	39	0.73 (0.39, 0.94)	0.68 (0.55, 0.80)
Gómez-Puerta et al. 2018 [37]		R-SLEDAI	30	12	15	19	0.67 (0.51, 0.80)	0.61 (0.42, 0.78)
Part 3: the diagnostic accuracy for uNGAL to predict renal flare
Hinze et al. 2009 [22]		R-SLEDAI	13	15	3	32	0.81 (0.54, 0.96)	0.68 (0.53, 0.81)
Rubinstein et al. 2010 [23]	13.6 ng/ml	R-SLEDAI	26	13	3	35	0.90 (0.73, 0.98)	0.73 (0.58, 0.85)
Rubinstein et al. 2010 [23]	13.6 ng/ml	BILAG2004	6	13	2	10	0.75 (0.35, 0.97)	0.44 (0.23, 0.66)
Torres-Salido et al. 2014 [29]	0.421 ng/ml Cr	Proteinuria	4	12	6	23	0.40 (0.12, 0.74)	0.66 (0.48, 0.81)
Watson et al. 2014 [30]	30 ng/ml	pBILAG	11	59	7	88	0.61 (0.36, 0.83)	0.60 (0.51, 0.68)
Elewa et al. 2015 [31]		R-SLEDAI	16	8	0	37	1.00 (0.79, 1.00)	0.82 (0.68, 0.92)
Part 4: the diagnostic accuracy for uNGAL to identify proliferative LN
Hammad et al. 2013 [26]	10.07 ng/mg Cr	Biopsy	11	3	1	7	0.92 (0.62, 1.00)	0.70 (0.35, 0.93)
Tawfik et al. 2015 [33]	18 ng/ml	Biopsy	9	1	2	2	0.82 (0.48, 0.98)	0.67 (0.09, 0.99)

TP: true positive; FP: false positive; FN: false negative; TN: true negative; CI: confidence interval; uNGAL: urinary neutrophil gelatinase-associated lipocalin; LN: lupus nephritis; R-SLEDAI: renal Systemic Lupus Erythematosus Disease Activity Index; SLICC: Systemic Lupus International Collaborating Clinics renal activity score; BAI: biopsy activity index; UPCR: urinary protein/creatinine ratio; pBILAG: the global paediatric version of the British Isles Lupus Assessment Group 2004 index; BILAG2004: British Isles Lupus Assessment Group 2004 index.