(Received November 2, 1970; revision accepted for publication March 4, 1971.)
Supported in part by United States Public Health Service Grant HD-01965-04 and HD-01965-05.
ADDRESS FOR REPRINTS: (W.E.H.) Department of Pediatrics, University of Colorado Medical Center,
4200 East Ninth Avenue, Denver, Colorado 80220.
PF.rnAmIcs, Vol. 48, No. 2, August 1971
THE
HISTOCHEMICAL
NITROBLUE
TETRAZOLIUM
REDUCTION
TEST IN THE
DIFFERENTIAL
DIAGNOSIS
OF
ACUTE
INFECTIONS
James R. Humbert, M.D., Melvin I. Marks, M.D., William E. Hathaway, M.D.,
and Christine H. Thoren
From the Department of Pediatrics, University of Colorado School of Medicine, Denver, Colorado
ABSTRACT. Nitroblue tetrazolium (NBT) reduc-tion by phagocytic leukocytes was investigated his-tochemically in 296 subjects with and without in-fections. Among 130 patients with noninfectious
diseases, osteogenesis imperfecta patients and their
relatives, and hemophiliacs frequently displayed high NBT-reduction values in their neutrophils.
Four percent of the other noninfected patients
yielded NBT-reduction values higher than normal
in their neutrophils and were considered to have
“false-positive” NBT-reduction tests. Most patients with acute bacterial infections (83%) showed an increased percentage of NBT-positive neutrophils. In patients who did not respond to a bacterial in-fection by increasing their percentage of
NBT-pos-itive neutrophils, there was suggestive evidence of
a state of neutrophil dysfunction. Eighty-four per-cent of patients with viral or tuberculous infections demonstrated normal percentages of NBT-positive neutrophils. Acute bacterial infections were most often associated with a high percent of NBT-posi-tive neutrophils, while low values predominated in viral infections regardless of the patient’s total leu-kocyte counts. The NBT histochemical test would appear to be a useful adjunct to microbiologic techniques in establishing the diagnosis in patients with suspected infection.
Pediatrics, 48:259, 1971, PHAGOCYTIC
LEUKO-CYTES, NJTROBLUE TETRAZOLIUM DYE, BACTERIAL
INFECTIONS, VIRAL INFECTIONS.
P
GT05I5 increases nitrobluetetra-zolium (NBT) reduction in circulating
phagocytic leukocytes.1’2 Normal
individu-als who have bacterial infections may
there-fore be expected to have an increased
per-centage of phagocytes containing reduced
NBT. A preliminary report by Park and
as-soeiates3 demonstrated the anticipated
in-crease in NBT reduction by neutrophils of
patients with bacterial infections as
op-posed to normal values observed in cases of
viral or tuberculous disease. The purpose of
this investigation was to evaluate the
NBT-reduction histochemical test in 246 patients
who had a variety of viral and bacterial
ill-nesses and noninfeetious diseases.
MATERIAL AND METHODS
Most of the subjects studied were
chil-dren between the ages of 2 months and 17
years who were patients at the University
of Colorado Medical Center between
Octo-ben 1968 and March 1970. A few adult
pa-tients and children from other hospitals in
Denver were also examined. Infants less
than 1 month of age were excluded from
the study since newborn infants have
spon-taneously high NBT-reduction values in
their phagocytie cells. Controls consisted
of 50 healthy adults. Heparinized blood
samples were processed within 30 minutes
after venipuncture. The method used for
the NBT-reduction histochemical test was
essentially that of Park and others3 and has
been previously detailed.4 Only cells that
demonstrated a definite deposit of reduced
NBT were considered “NBT-positive
leuko-cytes.” Leukocytes in which reduced NBT
appeared merely as a uniform greyish hue or
as fine punctate deposits no larger than
granules of neutrophils were not regarded
as NBT-positive. The percentage of
NBT-positive neutrophils was determined after
TABLE I
l)IAGN0SIs IN 130 NONINFECTED PATIENTS
Osteogenesis Imperfecta
-patients
-relatives
Infectious, recovered Leukemia orlyznphoma Recurrent infection Kidney or liver transptant Ilemophihia
Cirrhosis of the liver Rheumatoid arthritis Hypogammaglobulinemia
Sicklecell anemia Renal failure
Thrombocytopenic purpura Acanthocytosis
Ataxia telang,ectasia Cystinosis Lupus erythematosus Burns Cyclic neutropenia Aspirin poisoning
Liver failure Neuroblastoma
Wilson’s disease 10 Acute hemorrhage 16 Diabetes 10 Fat necrosis 10 Chromosome-ring 18
9 Desquamative pulmonary 9 disease
6 Thymic dyspla.sia S lleart failure
4 Mongolism S Mental retardation S Cornelia de Lange S syndrome 3 Aplastic anemia
Rheumatic fever Trimetbylaininuria Glycogen storage disease
2 Intestinal telangiectasia
2 Collagen disease 2 hypothyroidism
2 Posterior uveitis 2 Stevens-Johnson’s
2 ayndrome
Fic. 1. Nitroblue tetrazolium reduction by leuko-cytes of 130 noninfected patients. Horizontal bar and shaded area = mean and range for 49 normal adult controls. Open circles = osteogenesis imper-fecta (patients or relatives ). Stars = hemophilia pa-tients. Closed circles = other patients.
Phago-cytes = neutrophils and monocytes. Numbers
re-fer to cases discussed in the text.
260
the light microscope. In normal
prepara-tions monocytes constituted such a small
number of circulating leukocytes that the
exact percentage of these cells containing
reduced NBT was not determined. Instead,
neutrophils and monocytes were grouped
together and referred to as “phagocytes.”
The percentage of NBT-positive
phago-cytes was established in order to have
val-ues with which to correlate quantitative
= NBT-reduetion tests.2’4 Eosinophils, which
never reduced NBT spontaneously in
nor-1 mal subjects, were excluded from the
counts. A total leukocyte count was
oh-tamed from each patient at the time of the
NBT-reduction test.
1 “Noninfected patients” consisted of
chil-dren or adults in whom no clinical or
bacte-riologieal evidence of infection was present
at the time of the test. A histochemical
I NBT-reduction test was done on these
pa-tients for several reasons. These cases
in-1 eluded patients with a history of recurrent
infection, fever or leukoeytosis of unknown
1 #{149} origin, or patients after recovery from
infee-1 tions. The list of diagnoses is included in
- Table I.
Appropriate specimens for bacterial and
viral cultures and serological testing were
obtained from patients with infections upon
entry to the study (usually at the time of
the NBT testing. ) Bacteria were identified
by colonial morphology and standard
bio-chemical tests in the clinical microbiology
laboratories of the University of Colorado
Medical Center. Virus identification was
based upon cytopathogenie effect,
hemad-sorption, and neutralization tests; suckling
mice and three cell lines (Rhesus monkey
kidney, W1-38 and Hep 2) were employed.
The majority of patients with infections
had fever above 38#{176}Cat the time of the
NBT test.
“Definite” bacterial or viral infections
consisted of eases in which a specific
orga-nism had been isolated from the focus of
TABLE II
NITROBLUE TETRAZOLIUM REDUCTION I N LEUKOCYTES OF INFECTED AND NOMNFECTED SUBJECTS
261
patient’s illness. The only exceptions were
three children with typical lobar
pneumo-nia who responded rapidly to penicillin
treatment, and in whom pure cultures of
Diplococcus pneumoniae were grown from
nasopharyngeal swabs; these patients were
considered to have bacterial pneumonia.
“Probable” bacterial or viral infections
in-eluded patients in whom a pathogenic
or-ganism was not isolated from the focus of
infection (this was the case with most
respi-ratory infections ), but in whom the
diag-nosis was established by the clinician and
the Infectious Disease consultants without
regard for the NBT-reduetion test results.
“Indolent” infections made up a
heteroge-neous group of patients in whom a
nonsys-temic low-grade or chronic infection was
diagnosed. Patients with superficial skin
in-fections, asthma, asymptomatic subjects
fin-ishing a course of antibiotics for an acute
disease, and asymptomatic carriers of
patho-genie bacteria were included in that group.
The Student “t” test was used for the
statis-tical analysis of the results which are
re-ported as the mean ± the standard error of
the mean (SEM ) unless stated otherwise.
RESULTS
The majority of monocytes examined in
infected and noninfected subjects contained
large intense deposits of reduced NBT. As a
result, the percentage of NBT-positive
phagocytes gave values generally higher
than, but parallel to, those of NBT-positive
neutrophils. IBT reduction by phagocytes
will thus be analyzed in this report only
when pertinent.
Normal Controls
The percentage of neutrophils containing
reduced NBT (“NBT-positive neutrophils”)
was 7.7 ± 0.3% with a range of 1 to 15% in
normal adults. One apparently healthy adult
showed a percentage of NBT-positive
neu-trophils four standard deviations above the
mean and was not included in the statistical
evaluation of the results. A normal subject,
studied 16 times over an 18-month period
had a percentage of NBT-positive
neutno-.
Group of Subjects
Percentages of
NBT-Posilive
Neutrop/ills Phagocytes
Normal adults (49) 7.7±0.3 14.6±0.3
Noninfected patientst (98) 7. 1 ±0.6 13 .6 ± 0.9 Definite acute bacterial
infections (39) 5.1 S1.3±3.3
Probable acute bacterial
infections (13) 35.±5.S 46.3±5.0
All acute bacterial
infections (5) 35.6±.9
Indolent bacterial
infections(20) 10.7±.3 17.7±.S
1)efluiite viral or the
infections(30) 13.3±3.5 0.5±3.S
Probable viral
infeetions(13) 7.6±.7 15.0±5.’
All viral or the
infeetions(43) 11.4±.6 19.1±3.1
* p<0.01 when compared with normal adults or
iioii-infected patients.
t Excluding hemophilia or osteogenesis imperfecta patients (see text).
Excluding a chronic granuloniatous disease patient.
§Mean±SEM.
Numbers in parenthesis =nulnl)er of subjects in each group.
The tuberculous.
phils of 5.6 ± 0.3% (range 2 to 13%) . The
percentage of NBT-positive phagocytes was
14.6 ± 0.3% (range 4 to 26%) in normal
adults.
Patients Without Infectious Diseases
One hundred and thirty patients without
detectable infection were available for
study. They ranged in age from 1 month to
54 years and 25% were adults older than 20
years. Forty-two different diagnoses were
represented in that group (Table I).The
re-sults of their NBT-reduction tests are
sum-manized in Figure 1.
Two groups of patients appeared to have
80
0
.2.460
.50
I
.
a
30
#{149}11
06 #{149}1
.5 .13
.12
#{149}14
infections
(53
rial
Infect.
Ftc. 2. Nitroblue tetrazolium reduction by neutrophils of patients with in-fections. Shaded area = normal range. Dark circles = definite infections. Open circles = probable infections. Stars = tuberculosis. Horizontal bar =
mean. Numbers refer to cases discussed in the text.
range: hemophilia patients, in whom four
of six showed a percentage of NBT-positive
neutrophils above normal values, and
pa-tients with osteogenesis imperfecta or their
immediate relatives, in whom 8 of 26
dis-played high results. Excluding these 32
pa-tients, the percentage of NBT-positive
neu-trophils and phagocytes was 7.1 ± 0.6%
and 13.6 ± 0.9% respectively, vhich is
es-sentially identical with the values obtained
in normal adult controls (Table II).
Four other children with elevated NBT
reduction in leukocytes were also seen. The
ease numbers correspond to those used in
Figure 1. Case 1 was a 9-year-old male with
active rheumatic fever under treatment
with aspirin and penicillin. Streptococcus
7O
0.
2
I!
I:
dO
pyogenes was not isolated by throat culture.
Case 2 was a 12-year-old male with a fever
of unknown origin suspected of rheumatic
fever or rheumatoid arthritis and whose
only abnormal laboratory test was an
in-creased sedimentation rate. Case 3 was a
2-month-old male with heart failure and
probable endocardial fibroelastosis. Case 4
was a 1-year-old girl with recurrent
pulmo-nary infections who was apparently well at
the time of the study.
Patients with Acute Bacterial Infections
The results of the NBT-reduction
histo-chemical test in 53 patients with 40 definite
and 13 probable acute bacterial infections
TABLE III
I)IAGNOSIS IN 96 PATIENTS WITH ACUTE INFECTIONS
263
2. The diagnoses of these patients are listed
in Table III. Fifteen different organisms
were isolated in these patients. Thirty-two
patients were infected with gram-positive
bacteria (Staphylococcus aureus, or
epider-midis, Diplococcus pneumoniae and
Strep-tococcus pyogenes or viridans ).
Cram-nega-tive organisms were recovered in 23 cases
and consisted mostly of Neisseria
meningi-tidis, Haemophilus influenzae,
Pseudomo-flSLI aeruginosa and Salmonella species.
0th-en gram-negative bacteria included Listeria
monocytogenes, Serratia marcescens,
Kieb-siella pneumoniae and Shigella sonnei.
Cartdida albicans was cultured on two
ocea-sions and Pneumocystis carinii was
demon-strated histologically once. Definite and
probable bacterial infections yielded the
same high percentages of NBT-positive
neutrophils and were pooled for further
an-alysis. The percentage of NBT-positive
net’-trophils was 27.7 ± 2.5% and 35.6 ± 2.9% in
phagocytes; both results are significantly
higher than in controls or noninfected
pa-tients (p < 0.01, Table II).
“False-negative” NBT-Reduction Tests: Normal Values in 10 Patients with
Acute Bacterial Infections
Ten patients with bacterial infections
were within or below the range of normal
values. Their case numbers refer to those
used in Figure 2, Column 1. They included
a sickle cell anemia patient with Salmonella
typhirnurium osteomyelitis (Case 1); two
patients with septicemia on cytotoxic drugs
(histiocytosis X receiving vinbiastine, Case
2, and lymphoma treated with nitrogen
mus-tard, Case 9); three eases of infected
yen-tniculo-penitoneal shunts, including two
caused by Staphykcoccus epidermis (Cases
3 and 7 ), and one case of an alcoholic with
Pseudomonas aeruginosa brain abscesses
(Case 8) ; another alcoholic with
Strepto-coccus pyogenes subdural empyema (Case
5) ; a patient with severe bums and
Pseudo-monas aeruginosa and Candida albicans
septicemia (Case 4) ; one case of
pneumo-nia complicating an influenza syndrome
Acute bacterial infection Viral or tuberculous infection
Z%Tum-
1\’uin-Diagnosis ber of
cases*
Diagnosis ber of
cases
Meningitis I 1 Meningitis .20
Septicentia
Abscess
I 0
5
Broncho-pulmonary infection Encephalitis
,5 4
Broncho- Pharyngitis
pneumonia 5
Acute osteomyelitis 4 Pneumonia ‘2
Cervical Arachnoiditis 1
lymphadenitis 3
Infected ventricu- Arthritis 1
loperitoneal
shunt 3
Lobar pneumonia 3 Myelitis 1
Purulent phlebitis ‘2 Influenza syndrome 1
Tonsillitis ‘2 Progressive vaccinia 1
Purulent otitis Otitis media I
media ‘2
Cellulitis ‘2 Bronchitis 1
Subdural einpyenaa 1 Viremia 1
Peritonitis 1 Herpes aoster 1
Scarlet fever 1 Parotitis 1
Gastroenteritis 1
* Since some patients had more than one diagnosis, the number of diagnoses exceeds the number of patients.
(Case 10 ); and a patient with chronic
gran-ulomatous disease infected with Staph
yb-coccus aureus, Pseudomonizs aeruginosa
and Serratia marcescens (Case 6).
Patients with Indolent Bacterial Infections
The results of the NBT test in these 20
patients are shown in Figure 2, Column 2.
NBT reduction was normal in four patients
with chronic pulmonary disease (including
three asthma patients, and one patient with
bronchiectasis ), four asymptomatic carriers
of Streptococcus pyogenes (Group A ),
Sal-monella species (Groups B and C ) or
Shi-gella sonnei, five asymptomatic patients
recovering from acute infections and still
under antibiotic therapy, two patients with
TABLE IV
NITRomu E TETIIAZOLIUM REDUCTIoN I N NElTROPHILS
OF LF:tK0PENIC5 PATIENTS WITH
ACUTE INFEcTIoNs
Percentage
Leukocyte of
NBT-Dlagno.os Count
Potatwe (per cu mm)
A eutrophils 1390 ‘20 3250 300 3200 20 70 2300 ‘2800 25 47 4380 6
MEAN±SEM ‘2560±396 ‘28.3±6.8
Viral Infections Mumps meningitis
Mumps meningitis
Western equine meningitis herpes zoster, leukemia
Pneumonia Upper respiratory mfectionl 3900 4500 4980 200() 1760 4700 12 1 9 12 18 1
Mean±SEM 3640±576 8.8±2.7
pvaluet >0.1 <0.01
lescent boy carrier for Neisseria
meningi-tidis (Case 12), and an asthmatic child with
a history of frequent pulmonary infections
(
Case 14)
. (Case numbers correspond tonumbers recorded on Figure 2, Column 2).
The percentage of NBT-positive
neutro-phils and phagocytes in cases of indolent
infections was respectively 10.7 ± 2.3% and
17.7 ± 2.8%; these results were not signif-ieantly different from those of normal adult
controls or noninfected patients
(
p > 0.1,Table II).
Patients with Viral or Tuberculous
Infections
The 15 different diagnoses of the group
are listed in Table III; 60% of the 43
pa-tients had an infection of the nervous
sys-tem. Thirteen different viruses were
re-covered from the patients : Herpes zoster or
simplex, Mumps, Rubeola, Influenza B,
Pa-rainfluenza-1, Echovirus 2, 6, or 30,
Cox-sackie B-3, Cytomegalovirus, Western
equine and Vaccinia. In addition, two
en-teroviruses were grown but not typed.
Three cases of tuberculosis were included.
The 11.4 ± 2.6% of neutrophils and 19.1 ±
3.1% of phagocytes reduced NBT; these
values were not significantly higher than
those of the two control groups. In 36 cases
(84%) the NBT-reduction value in
leuko-cytes was within the normal range
(
Fig. 2,Column 3
)
. All three cases of tuberculosisalso showed percentages of NBT-positive
neutrophils within the normal range.
“False-Positive” NBT-Reduction Tests:
High Values in Seven Patients with Viral Infections
Seven cases with definite or probable
vi-ral infections displayed an abnormally high
percentage of NBT-positive neutrophils.
They included four of six patients with
proven echovirus infections and clinical
meningitis
(
Cases 1, 2, 4, 5) ; a child withaseptic meningitis
(
Case 3) who hadnega-tive viral cultures; and two nonbactenial
re-spiratory infections
(
one with sterile viralcultures, Case 6, the other yielding Herpes
simplex from a throat culture, Case 7).
‘lie percentage of NBT-positive neutropliils is sig-nificantly higher (p <0.01) in leukopenic patients with bacterial infection than iti those with viral infections.
* Leukocyte counts less than 5000 per cu. mm.
t When values in bacterial infections are compared with those in viral infections.
Ilerpes simplex isolated from the throat.
§No specific virus isolated.
low-grade, chronic osteomyelitis due to
Staphylococcus aureus. Four patients
(
noneof whom were receiving any antibiotics)
showed a percentage of NBT-positive
neu-trophils higher than normal: a child with
impetigo
(
Case 11 ), one with chronicallyinfected bronchiectasis
(
Case 13)
, anado-Bacterial Infections Listeria meningitis Pseudomonas septiceiiiia, burns Staphylococcal sepsis, leukemia Meningococcal meiiiiigitis Pseudomonas peritonitis, leukemia Ilemophilus sepsis Filebsiella-Candida septicensia
Ilezuophilus otitis media Lymphoma, probable
septicemia
‘2300 ‘23
( Case numbers refer to those recorded on
Figure 2, Column 3.)
Leukocyte Counts in Infected Patients
Except for two patients with very high
leukocyte counts
(
40,000/cu mm)
, thesub-jeets with acute bacterial infections did
not differ in total leukocyte counts from
those with viral disease. Including these
two patients, the leukocyte count was
14,600 ± 1770 in patients with bacterial
infections as compared with 10,600 ± 960
in viral eases; this was an insignificant
difference (p > 0.1 ). All acutely infected
patients with leukopenia (leukocyte counts
less than 5000/cu mm
)
were analyzedseparately for NBT reduction in their
net:-trophils (Table IV ). In this group a
sig-nffieantly higher percentage of neutrophils
(28.3 ± 6.8%) reduced NBT in cases of
bacterial infections than in viral illnesses
(8.8 ± 2.7%, p < 0.01 ). The difference
remained significant when absolute
num-bers of neutrophils containing NBT were
calculated for this group as well as for the
leukocytosis groups. Leukocytosis
aceom-panying conditions other than infections
did not cause an abnormal elevation of
NBT reduction in neutrophils. In particular,
all 10 noninfeeted patients with leukoeyte
counts greater than 15,000/cu mm
(
mean= 22,060 ± 1320) yielded normal
percent-ages of NBT-positive neutrophils
(
7.3 ±1.3%, range 1-14%). These 10 patients also
had a predominance of granulocytes in
their differential leukocyte counts. Although
correlation coefficients between
tempera-tunes and percentages of NBT-positive
neu-trophils were not done, fever per se did
not appear to influence NBT reduction by
neutrophils; this was illustrated by six
pa-tients with temperatures above 39.5#{176}who
did not have any infection and who showed
normal values for NBT reduction in their
neutrophils (range 1-10%).
DISCUSSION
The percentage of normal neutrophils
(bands and segmented) undergoing
spon-taneous NBT reduction in peripheral blood
(
7.7 ± 0.3%) correlates well with that ofPark and associates.3 Using a slightly
differ-ent system
(
a longer incubation of 30min-utes and a two time higher NBT
concentra-tion), they found 8.2% (range 3 to 11%)
of NBT-positive neutrophils in normal
adults.
The exact percentage of NBT-positive
monocytes in each sample was not recorded
separately, but was combined with the
per-centage of neutrophils containing reduced
NBT. An estimate of the percentage of
phagocytes likely to reduce NBT was thus
provided for comparison to the quantitative
NBT-reduction test.2’4 Monocytes were
fre-quently noted to reduce NBT in large
amounts. This high NBT-reducing activity
of monocytes in normal subjects has not
been mentioned before in the literature.
Two diseases were characterized by a
number of “false-positive” results in the
ab-sence of infection. Of six patients with
he-mophilia, four had NBT-reduction values in
neutrophils exceeding the normal range
(
Fig. 1)
. These patients had either recentminor bleeding or transfusion therapy.
Neutrophilic leukocytes have been shown
to phagocytose fibnin within thnombi6 and
therefore may be stimulated in such clinical
instances. Since the number of patients was
small, further evaluation of their leukocytie
NBT-metabolism will be necessary before
speculating on the meaning of these results.
Thirty-two percent of patients with
os-teogenesis impenfecta
(
01), or theirimme-diate relatives, displayed an abnormally
high percentage of NBT-positive
neutro-phils. It has been shown that oxygen
eon-sumption and pentose phosphate pathway
activity is considerably increased in 01
leti-kocytes.7 Other “false-positive”
NBT-re-duction tests mentioned in the literature
have applied to newborn infants and
sub-jects who had received typhoid vaccine.8
This study of 53 acute bacterial
infec-tions with the NBT-reduction tests
eon-firmed the preliminary report by Park and
others;3 namely, beyond the neonatal
pe-nod there exists in patients with acute
266
In 25 cases of viral central nervous
sys-percentage of NBT-positive leukocytes as
compared with normal controls, patients
with noninfectious illnesses, and those with
viral or tubereulous infections
(
Fig. 2,Table II ). Patients with acute infections
were usually studied immediately upon
ar-rival to the hospital before any antibiotic
treatment. Since no serial NBT tests were
done in infected patients after the onset of
antibiotic therapy, the effect of antibiotics
on NBT-reduction by neutrophils cannot be
assessed from this study.
The present study provides additional
in-formation regarding patients with
false-negative NBT-reduction tests. The only
reported cases with absent or low NBT
re-duction by neutrophils in the presence of
infection have been children with chronic
granulomatous disease.1’2’ The patient
with chronic granulomatous disease
re-duced no NBT in any phagocyte, and was
excluded from statistical analyses, since this
anomaly of his white blood cells was
ex-pected. Expressed differently, the
NBT-re-duction test was positive in 83% of cases of acute bacterial infections and failed to
cor-relate with that diagnosis in 17% of the
pa-tients.
Complicating factors present in the
pa-tients with false-negative NBT-reduction
may have altered white cell function in this
group. These factors include vascular
insuf-ficiency preventing arrival of neutrophils to
focus of infeetion
(
Case 1)
;chemother-apy1#{176}
(
Cases 2, 9)
; 1 surgicalstress1
(
Cases 3 and 7)
; thermal burns12(Case 14); and influenza virus’3 (Case 10).
In contrast, all the normal hosts, i.e., the
re-mainder of the patients, showed a high
NBT-reduetion value in the presence of an
acute bacterial infection. This is well
illus-trated by the 11 cases of acute bacterial
meningitis (all children) who showed the
expected increase in percentage of NBT
positive neutrophils. This confirms Park’s
findings in 19 patients with meningitis.3 In
this group of patients, the NBT-reduction
test has been positive in 100% of the
sub-jects.
tem infections, five showed false-positive
results with the NBT-reduetion test. They
were all aseptic meningitis which occurred
during an Echovirus 30 meningitis
epi-demic period; a specific echovirus was
iso-lated in four of these cases
(
1, 2, 4 and 5),and suspected but not proven in another
(
Case 3)
. In our series, only echovirusmeningitis were frequently associated with
a high value in the percentage of
NBT-pos-itive neutrophils. This finding warrants
fur-ther investigation regarding the effect of
echoviruses on the metabolism of
neutro-phils.
The leukocyte counts in both bacterial
and nonbaetenial infections were about
equally distributed between low, normal,
and high values. There were, in fact, a few
more leukopenic cases among bacterial
than among viral infections
(
Table IV) . Incontrast, the NBT-reduction test was useful
in differentiating acute bacterial infections
from viral infections, mycobactenial, or
non-infectious conditions in most patients,
re-gardless of their total leukocyte counts.
Pa-tients with leukopenia displayed the same
trend as other patients in regard to NBT
re-duction in their neutrophils : the percentage
of NBT positive neutrophils was elevated in
acute bacterial illnesses, but was normal in
viral infections.
IMPLICATIONS
Because of its simplicity in performance,
the NBT-reduction histochemical test
should be further evaluated in patients with
suspected infections; if reliable, this test
may be a particularly useful adjunct in
di-agnosis of acute bacterial infections in
am-bulatory patients. However, because of the
number of “false-positive” and
“false-nega-tive” results, it should not replace standard
microbiologic techniques in such clinical
situations.
REFERENCES
1. Baehner, R. L., and Nathan, D. C.: Quantita-tive nitroblue tetrazohium test in chronic granulomatous disease. New Eng. J. Med.,
278:971, 1968.
D. K.: Failure of nitroblue tetrazolium re-duction in the phagocytic vacuoles of leuko-cytes in chronic granulomatous disease. J.
Clin. Invest., 48: 1895, 1969.
3. Park, B. H., Fikrig, S. M., and Smithwick, E.
M. : Infection and nitroblue tetrazolium
re-duction by neutrophils. A diagnostic aid.
Lancet, 2:532, 1968.
4. Humbert, J. R., Kurtz, M. L., and Hathaway,
W. E. : Increased reduction of nitroblue
te-trazolium by neutrophils of newborn infants.
PEDIATRICs, 45:125, 1970.
5. Lennette, E. H., and Schmidt, N. J., ed: Diag-nostic Procedures for Viral and Rickettsial Infections, ed. 4. New York: American Pub-lic Health Association, 1969.
6. Barnhart, M. I.: Importance of neutrophihic
leukocytes in the resolution of fibrin. Fed.
Proc., 24:846, 1965.
7. Humbert, J. R., Solomons, C. C., and Ott, J.
E.: Osteogenesis imperfecta. Increased
oxi-dative metabolism by leukocytes. J. Pediat,
in press.
8. Crush, 0. C., and Mauer, A. M. : Neutrophil
function and NBT dye reduction. Lancet, 2:
383, 1969.
9. Waldvogel, F. A., Medoff, C., and Swartz, M.
N. : Osteomyehitis (third of three parts). Os-teomyehitis: A review of clinical features, therapeutic considerations and unusual as-pects. 3. Osteomyelitis associated with
vas-cular insufficiency. New Eng. J. Med., 282:
316, 1970.
10. Malawista, S. E.: Vinbiastine: Cochicine-like
effects on human blood leukocytes. Arthritis Rheum., 11:108, 1968.
11. Brayton, R. C., Stokes, P. E., Schwartz, M. S., and Lauria, D. B.: Effect of alcohol and
var-ious diseases on leukocyte function. New
Eng. J. Med., 282:123, 1970.
12. Alexander, J. W., Hegg, M., and Altemeier, W. A.: Neutrophil function in selected surgical disorders. Ann. Surg., 168:447, 1968.
