Sensitivity of diagnosis of spontaneous bacterial peritonitis is higher with the automated cell count method

Table 1 Type of bacteria according to their pathogenicity in spontaneous bacterial peritonitis

	Bacteria
Pathogenic
	Staphylococcus aureus
	Enterococcus faecalis
	Enterococcus faecium
	Escherichia coli
	Klebsiella pneumoniae
	Pseudomona aeruginosa
	Anaerobes
	Clostridium innocuum
	Streptococcus gallolyticus
	Streptococcus agalactie
Indeterminate
	Sphingomonas paucimobilis
	Acinetobacter sp.
	Streptococcus sanguinis
	Streptococcus parasanguinis
	Streptococcus salivarius
Non-pathogenic
	Staphylococcus epidermidis
	Staphylococcus capitis
	Staphylococcus haemolyticus
	Staphylococcus hominis
	Staphylococcus saprophyticus
	Staphylococcus pasteuri
	Staphylococcus pettenkoferi
	Staphylococcus warneri
	Staphylococcus saccharolyticus
	Corynebacterium striatum
	Corynebacterium jeikeium
	Micrococcus luteus
	Dermacoccus nishinomiyaensis
	Kocuria rhizophilia

Table 2 Performance of automated and manual cell count methods in cohort 2 employing different cutoffs, n (%)

	SBP		Total
	Positive	Negative
Manual method cell count
Result cutoff ≥ 200 cells × 106
Positive	19 (61)	0	19
Negative	12	50 (100)	62
Total	31	50	81
Result cutoff ≥ 250 cells × 106
Positive	18 (58)	0	18
Negative	13	50 (100)	63
Total	31	50	81
Result cutoff ≥ 300 cells × 106
Positive	18 (58)	0	18
Negative	13	50 (100)	63
Total	31	50	81
Automated method cell count
Result cutoff ≥ 0.1 cells × 109/L
Positive	24 (89)	26	50
Negative	3	25 (49)	28
Total	27	51	78
Result cutoff ≥ 0.2 cells × 109/L
Positive	21 (78)	2	50
Negative	6	49 (96)	28
Total	27	51	78
Result cutoff ≥ 0.3 cells × 109/L
Positive	20 (74)	0	20
Negative	7	51 (100)	58
Total	27	51	78
Result cutoff ≥ 0.4 cells × 109/L
Positive	19 (70)	0	20
Negative	8	51 (100)	58
Total	27	51	78

SBP: Spontaneous bacterial peritonitis.

Table 3 Clinical and biochemical characteristics of positive-spontaneous bacterial peritonitis and negative-spontaneous bacterial peritonitis cases in cohort 1, n (%)/mean ± SD

	Negative-SBP (n = 132)	Positive-SBP (n = 5)	P value
Demographic and clinical characteristics
Male sex	73 (55)	3 (60)	1.0
Age (years)	62.1 ± 12.9	71.8 ± 14.2	0.10
Diabetes	23 (21)	2 (40)	0.30
Betablockers	40 (37)	3 (60)	0.61
Immunosuppression	2 (2)	1 (20)	0.13
SBP prophylaxis	26 (24)	0	0.59
Rifaximin	6 (6)	0	1.0
Alcohol-related cirrhosis	94 (71)	3 (60)	0.51
Main cause of admission
Infection	34 (26)	2 (40)	0.35
Ascites	62 (47)	2 (40)
Jaundice	9 (7)	1 (20)
Encephalopathy	9 (7)	0
UGIB	11 (8)	0
AKI	2 (1)	0
Other1	5 (4)	0
Admission in ITU	5 (4)	0	1.0
Shock	2 (2)	0	1.0
Hospital mortality	9/85 (11)	2/5 (40)	0.11
Liver and renal function
Bilirubin (µmol/L)	99 ± 115	188 ± 208	0.10
Albumin (g/L)	28 ± 5	29 ± 4	0.91
INR	1.5 ± 0.4	2.0 ± 0.5	0.01
Ascites-Grade 32	84 (64)	2 (40)	0.36
Encephalopathy
Grade 0-1	91 (69)	3 (60)	0.53
Grade 2-3	41 (31)	2 (40)
Creatinine (µmol/L)	84 ± 47	104 ± 56	0.36
Sodium (mmol/L)	132 ± 6	133 ± 7	0.99
Child-Pugh (score)	10.1 ± 1.7	12.0 ± 1.0	0.02
MELD score (points)	19 ± 7	25 ± 7	0.06
UKELD score (points)	58 ± 5	61 ± 2	0.25
CLIF-C ACLF score (points)	43.3 ± 8.4	53.5 ± 7.3	0.02
ACLF grade
No ACLF	68 (57)	3 (60)	0.66
ACLF grade 1	40 (33)	1 (20)
ACLF grade 2-3	12 (10)	1 (20)

¹2 cases with anemia, 2 cases with hyponatremia and falls, and 1 case with hip fracture decompensated with ascites after surgery.

²All other cases had grade-2 ascites.

SBP: Spontaneous bacterial peritonitis; UGIB: Upper gastrointestinal bleeding; AKI: Acute kidney injury; ITU: Intensive therapy unit; INR: International normalized ratio; MELD: Model for end-stage liver disease; UKELD: United Kingdom end-stage liver disease; CLIF-C ACLF: Chronic liver failure consortium acute-on-chronic liver failure.

Table 4 Markers of infection and characteristics of ascitic fluid in positive-spontaneous bacterial peritonitis and negative-spontaneous bacterial peritonitis cases in cohort 1, n (%)/mean ± SD

	Negative-SBP (n = 132)	Positive-SBP (n = 5)	P value
Markers of inflammation
CRP (mg/L)	42 ± 40	59 ± 26	0.33
CRP > 5 mg/L	106 (89)	5 (100)	1.0
Leukocyte count in serum (× 109/L)	10.2 ± 6.6	7.5 ± 2.3	0.36
Neutrophil count in serum (× 109/L)	7.6 ± 5.7	5.8 ± 1.9	0.50
Temperature (°C)	37.0 ± 0.7	37.5 ± 0.3	0.14
Heart rate (beats per minute)	91 ± 15	92 ± 19	0.87
Respiratory rate (breaths per minute)	18 ± 4	19 ± 1	0.74
Presence of SIRS	33/108 (31)	0/5	0.17
MAP (mmHg)	79 ± 16	89 ± 10	0.19
Characteristics of the ascitic fluid
Albumin (g/L)	7.7 ± 4.9	8.5 ± 2.1	0.74
Auto. polymorph count (cells × 109/L)	0.47 ± 1.89	4.76 ± 3.86	< 0.001
Manual polymorph count (cells × 106/L)	72 ± 259	1226 ± 1706	< 0.001

SBP: Spontaneous bacterial peritonitis; CPR: C-reactive protein; SIRS: Systemic inflammatory response syndrome; MAP: Mean arterial pressure.

Table 5 Performance of automated and manual cell count methods in cohort 1, n (%)

	Positive-SBP	Negative-SBP	Total
Manual method cell count
Test result
Positive	2 (40)	6	8
Negative	3	122 (95)	125
Total	5	128	133
Automated method cell count
Test result
Positive	4 (80)	21	25
Negative	1	111 (84)	112
Total	5	132	137

SBP: Spontaneous bacterial peritonitis.

Table 6 Clinical and biochemical characteristics of positive-spontaneous bacterial peritonitis and negative-spontaneous bacterial peritonitis cases in cohort 2, n (%)/mean ± SD

	Negative-SBP (n = 52)	Positive-SBP (n = 33)	P value
Demographics and clinical characteristics
Male sex	21 (40)	17 (52)	0.37
Age (years)	55.0 ± 13.5	60.4 ± 14.8	0.08
Alcohol-related cirrhosis	45 (87)	29 (88)	0.16
Diabetes	6 (12)	7 (22)	0.23
Betablockers	16 (31)	13 (41)	0.48
Immunosuppression	0	1 (3)	0.38
SBP prophylaxis	24 (46)	5 (16)	0.005
Rifaximin	1 (2)	8 (25)	0.002
Main cause of admission
Elective LVP	52 (100)
Infection		17 (52)
Ascites		7 (21)
Jaundice		5 (15)
Encephalopathy		1 (3)
UGIB		1 (3)
AKI		2 (6)
Admission in ITU	0	7 (21)	< 0.001
Shock	0	7 (22)	< 0.001
Hospital mortality	0/52	14/33 (42)	< 0.001
Liver and renal function
Bilirubin (µmol/L)	42 ± 27	158 ± 164	< 0.001
Albumin (g/L)	30 ± 4	29 ± 5	0.23
INR	1.3 ± 0.2	1.8 ± 0.7	< 0.001
Ascites-Grade 31	49 (94)	20 (61)	< 0.001
Encephalopathy
Grade 0-1	52 (100)	17 (52)	< 0.001
Grade 2-3	0	16 (48%)

¹All other cases had grade-2 ascites.

SBP: Spontaneous bacterial peritonitis; LVP: Large volume paracentesis; UGIB: Upper gastrointestinal bleeding; AKI: Acute kidney injury; ITU: Intensive therapy unit; INR: International normalized ratio; MELD: Model for end-stage liver disease; UKELD: United Kingdom end-stage liver disease; CLIF-C ACLF: Chronic liver failure consortium acute-on-chronic liver failure.

Table 7 Markers of infection and characteristics of ascitic fluid in positive-spontaneous bacterial peritonitis and negative-spontaneous bacterial peritonitis cases in cohort 2, n (%)/mean ± SD

	Negative-SBP (n = 52)	Positive-SBP (n = 33)	P value
Markers of inflammation
CRP (mg/L)	22 ± 17	57 ± 47	< 0.001
CRP > 5 mg/L	24 (89)	30 (91)	1.00
Leukocyte count in serum (× 109/L)	7.3 ± 2.1	11.1 ± 5.1	< 0.001
Neutrophil count in serum (× 109/L)	5.0 ± 1.8	8.6 ± 4.4	< 0.001
Temperature (°C)	36.9 ± 0.3	37.1 ± 1.0	0.22
Heart rate (beats per minute)	102 ± 16	104 ± 20	0.75
Respiratory rate (breaths per minute)	18 ± 3	21 ± 5	0.02
Presence of SIRS	4 (13)	14 (50)	0.004
MAP (mmHg)	84 ± 12	74 ± 17	0.01
Characteristics of the ascitic fluid
Albumin (g/L)	8.0 ± 4.1	7.5 ± 5.8	0.61
Automated polymorph count (cells × 109/L)	0.06 ± 0.06	3.27 ± 3.68	< 0.001
Manual polymorph count (cells × 106/L)	20 ± 22	2157 ± 4105	< 0.001

SBP: Spontaneous bacterial peritonitis; CPR: C-reactive protein; SIRS: Systemic inflammatory response syndrome; MAP: mean arterial pressure.

Table 8 Performance of automated and manual cell count methods in cohort 2, n (%)

	Positive-SNP	Negative-SNP	Total
Manual method cell count
Test result
Positive	18 (58)	0	18
Negative	13	50 (100)	63
Total	31	50	81
Automated method cell count
Test result
Positive	21 (78)	2	23
Negative	6	49 (96)	55
Total	27	51	78

SBP: Spontaneous bacterial peritonitis.

Table 9 Performance of automated and manual cell count methods in cases having both methods performed in cohort 2, n (%)

	Automated method		Total
	Positive	Negative
Positive-SBP cases
Manual method
Positive	13	0	13 (52)
Negative	7	5	12
Total	20 (80)	5	25
Negative-SBP cases
Manual method
Positive	0	0	0
Negative	2	47	49 (100)
Total	0	47 (96)	49

SBP: Spontaneous bacterial peritonitis.

Table 10 Performance of automated and manual cell count methods, both with cutoff PMN ≥ 200 cells/mm³ in cases having both methods performed in cohort 2, n (%)

		Automated method			Total
		Positive	Negative
Positive-SBP cases
Manual method
Positive	14			0		14 (56)
Negative	6			5		11
Total	20 (80)			5		25
Negative-SBP cases
Manual method
Positive	0			0		0
Negative	2			47		49 (100)
Total	2			47 (96)		49

SBP: Spontaneous bacterial peritonitis.

Table 11 Microbiological characteristics of positive-spontaneous bacterial peritonitis cases, n (%)

	Positive-SBP (n = 33)
Origin of infection
Community-acquired	18 (55)
Healthcare-associated	11 (33)
Nosocomial	4 (12)
Cultures
Blood or urine culture taken	22 (67)
Blood or urine culture, same bacteria	8 (24)
Bacteria isolated
E. coli	18 (55)
Enterococcus faecium	8 (24)
Enterococcus faecalis	3 (9)
Klebsiella pneumoniae	1 (3)
S aureus	1 (3)
Streptococcus agalactie	1 (3)
Clostridium innocuum	1 (3)
Empirical antibiotic used
Piperacillin/tazobactam	15 (46)
meropenem	6 (18)
Levofloxacin	4 (12)
Co-amoxiclav	4 (12)
Teicoplanin	2 (6)
Tigecycline	1 (3)
Flucoxacillin	1 (3)

SBP: Spontaneous bacterial peritonitis.