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Journal of Clinical Microbiology, May 2003, p. 1991-1995, Vol. 41, No. 5
0095-1137/03/$08.00+0 DOI: 10.1128/JCM.41.5.1991-1995.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.
Simple and Fast Lateral Flow Test for Classification of Leprosy Patients and Identification of Contacts with High Risk of Developing Leprosy
S. Bührer-Sékula,1* H. L. Smits,1 G. C. Gussenhoven,1 J. van Leeuwen,1 S. Amador,2 T. Fujiwara,3 P. R. Klatser,1 and L. Oskam1
KIT (Royal Tropical Institute) Biomedical Research, 1105 AZ Amsterdam, The Netherlands,1
Department of Microbiology, Instituto Evandro Chagas, Belém, Pará, Brazil,2
Institute for Natural Science, Nara University, Nara 631-8502, Japan3
Received 9 December 2002/
Returned for modification 15 January 2003/
Accepted 11 February 2003

ABSTRACT
The interruption of leprosy transmission is one of the main
challenges for leprosy control programs since no consistent
evidence exists that transmission has been reduced after the
introduction of multidrug therapy. Sources of infection are
primarily people with high loads of bacteria with or without
clinical signs of leprosy. The availability of a simple test
system for the detection of antibodies to phenolic glycolipid-I
(PGL-I) of
Mycobacterium leprae to identify these individuals
may be important in the prevention of transmission. We have
developed a lateral flow assay, the ML Flow test, for the detection
of antibodies to PGL-I which takes only 10 min to perform. An
agreement of 91% was observed between enzyme-linked immunosorbent
assay and our test; the agreement beyond chance (kappa value)
was 0.77. We evaluated the use of whole blood by comparing 539
blood and serum samples from an area of high endemicity. The
observed agreement was 85.9% (kappa = 0.70). Storage of the
lateral flow test and the running buffer at 28°C for up
to 1 year did not influence the results of the assay. The sensitivity
of the ML Flow test in correctly classifying MB patients was
97.4%. The specificity of the ML Flow test, based on the results
of the control group, was 90.2%. The ML Flow test is a fast
and easy-to-perform method for the detection of immunoglobulin
M antibodies to PGL-I of
M. leprae. It does not require any
special equipment, and the highly stable reagents make the test
robust and suitable for use in tropical countries.

INTRODUCTION
Leprosy, a disease caused by
Mycobacterium leprae, particularly
affects the less privileged parts of the population in countries
where the disease is endemic. This intracellular bacillus is
assumed not to be very pathogenic, most infections do not result
in chronic disease but in skin lesions that heal spontaneously
(
13). Present forecasts suggest that, despite the slow decline
in leprosy transmission, millions of individuals will continue
to be infected and develop disease in the next 20 years, notwithstanding
the intense efforts to eliminate leprosy as a public health
problem. (A. Meima, W. C. Smith, G. J. van Oortmarssen, J. H.
Richardus, and J. D. F. Habbema, submitted for publication).
Leprosy can be successfully treated with multidrug therapy.
Delayed diagnosis increases the chance that leprosy is spread
in the community and results in more-severe nerve damage. Interruption
of leprosy transmission is one of the main challenges for leprosy
control programs. No consistent evidence exists that the incidence
of leprosy has been significantly reduced after the introduction
of multidrug therapy (
20). Sources of infection are particularly
patients with high loads of bacteria and, possibly, infected
persons in which the clinical signs have not yet become apparent.
The presence of antibodies to the M. leprae-specific phenolic glycolipid-I (PGL-I) correlates with the bacterial load of a leprosy patient (17). The large majority of paucibacillary (PB) patients are seronegative, whereas the large majority of multibacillary (MB) patients are seropositive (1, 5, 6, 8, 9). It has been shown that the presence of PGL-I antibodies can be used to classify confirmed leprosy patients as MB or PB for treatment purposes (3, 4). In addition, it was shown that PGL-I-seropositive contacts of leprosy patients have a higher risk of developing leprosy compared with PGL-I-seronegative contacts and that when they develop the disease, it is primarily MB (12). Consequently, identification of antibodies to PGL-I in contacts of leprosy patients may lead to earlier detection of disease and ultimately to prevention of transmission. A simple assay is required to routinely screen the contacts of leprosy patients.
Here, we describe a newly developed simple and rapid immunochromatographic flow test, the ML Flow test, for the detection of immunoglobulin M (IgM) to PGL-I in 10 min. In this study, we have investigated the performance of the ML Flow test for use on serum and whole-blood samples.

MATERIALS AND METHODS
ML Flow test.
The ML Flow test is composed of a nitrocellulose detection strip
that is flanked at one end by a reagent pad made from fiber-fleece
containing the dried colloidal gold-labeled anti-human IgM antibody
and at the other end by an absorption pad. A sample application
pad flanks the reagent pad in turn (Fig.
1). The semisynthetic
3,6-di-
O-methyl-ß-
D-glucopyranosyl-(1

4)-2,3-di-
O-methyl-

-
L-rhamnopyranosyl-(1

2)-3-
O-methyl-

-
L-rhamnopyranose
linked to bovine serum albumin (NT-P-BSA) (
14) was used as the
antigen. The trisaccharide represents the unique sugar moiety
of the
M. leprae PGL-I. The NT-P-BSA was deposited as a 1-mm-wide
line onto the nitrocellulose strip. Human IgM was deposited
as a second line parallel to the test line to function as a
reagent control. The composite was backed by a support and cut
into 5-mm-wide test strips to fit into a plastic housing with
a round sample application well positioned above the sample
pad and a square detection window positioned above the detection
strip.
The amounts of antigen and detection reagent were optimized
in a step-by-step procedure with a panel of positive and negative
control sera. The assay is performed by the addition of 5 µl
of undiluted serum or whole blood to the sample well followed
by the addition of 130 µl of running buffer (phosphate-buffered
saline containing 0.66 mg of BSA/ml and 3% Tween 20). The test
was read after 10 min for serum and after 5 and 10 min for blood.
The test result was only considered valid when the control line
was clearly visible. The test is scored positive when a distinct
staining of the test line is observed (Fig.
2, lanes 1+ to 4+).
When no staining (Fig.
2, lane -) or faint staining (Fig.
2,
lane +/-) is observed, the result is considered negative. To
increase stability, devices are individually packed in a moisture-resistant
sachet.
Study groups.
Test performance was determined on the following samples. (i)
Five hundred sixty-one serum samples collected in 3 areas of
high leprosy endemicity (Manaus in Brazil, South Sulawesi in
Indonesia, and Cebu in The Philippines) and 20 samples from
an area of low endemicity (Ghana). The sera were derived from
the following groups: (a) 114 newly diagnosed MB patients, (b)
85 newly diagnosed PB patients, (c) 42 household contacts of
leprosy patients, (d) 106 patients with skin diseases other
than leprosy (including 20 from patients with Buruli ulcers
from Ghana), (e) 234 healthy individuals (control group). (ii)
Ninety-nine serum samples came from an area of nonendemicity
(The Netherlands) (control group). (iii) Fifty-nine serum samples
were obtained in The Netherlands from patients with various
diseases other than leprosy (control group), including patients
with tuberculosis (
n = 12), human immunodeficiency virus (
n = 6), hepatitis A (
n = 3), hepatitis B (
n = 6), syphilis (
n = 6), malaria (
n = 9), toxoplasmosis (
n = 6), and autoimmune
disease (
n = 5) and rheumatoid factor-positive patients (
n =
6).
Both the ML Flow test and IgM enzyme-linked immunosorbent assay (ELISA) carried out according to Bührer et al. (4) were performed on these samples.
The ML Flow test performance with whole-blood samples was evaluated in a primary health center setting in an area of leprosy endemicity (Curionópolis, Pará, Brazil). Heparinized blood and serum samples were collected from 539 individuals (including newly diagnosed and treated leprosy patients, contacts, and healthy endemic controls) and tested immediately. All patients gave informed consent for serological testing; samples were coded and could not be related to patient names.
Storage experiments.
The ML Flow test and the detection reagent were stored for 1 year at three different temperatures (4, 28, and 45°C) and for 2 months at 55°C. The test strips' performance was checked by using a panel of 14 serum samples at various time points.
Statistical evaluation.
Data were analyzed by using Epi-info, version 6. The concordance between the test results of the two assays for a group of sera was determined by calculating the observed agreement and kappa values (
). Generally, a
value of 0.60 to 0.80 represents a substantial agreement beyond chance, and a
value of >0.80 represents almost perfect agreement beyond chance.

RESULTS
Comparison between ELISA and ML Flow test.
Table
1 shows the comparison between the ML Flow test and ELISA
for 739 sera from the Royal Tropical Institute serum bank. A
concordant result was observed for 673 samples in total. The
observed agreement between ML Flow and ELISA results was 91%
(

= 0.77; 95% confidence interval [CI], 0.70 to 0.84).
Seropositivity according to the classification of the study group.
The ML Flow test gave a positive result in 97.4% of the MB patients,
40% of the PB patients, 28.6% of the household contacts, and
9.8% of the controls (Table
2). Of the 98 MB patients with a
bacterial index of at least 2, 97.8% were ML Flow test positive.
The sensitivity of the ML Flow test to correctly classify MB
patients was 97.4% (95% CI, 93 to 99). The specificity of the
ML Flow test based on the results of the total control group
was 90.2% (95% CI, 87 to 93) or 86.2% (95% CI, 82 to 90), if
individuals from areas of nonendemicity are excluded. When testing
samples from people with skin diseases other than leprosy, there
was no particular skin disease that could be associated with
(high) seropositivity.
Comparison between the ML Flow test result when using whole blood and serum.
When testing 539 paired serum and whole-blood samples in the
ML Flow test, a concordant result was observed for 463 samples.
The observed agreement was 85.9% (

= 0.70; 95% CI, 0.62 to 0.79)
(Table
3).
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|
TABLE 3. Comparison between ML flow test on serum samples and on blood samples, both performed in a primary health care center setting
|
ML Flow test results with whole blood.
When testing 238 whole-blood samples with the ML Flow test with
5 and 10 µl of whole blood, a concordant result was observed
for 210 samples (Table
4). The observed agreement between the
test performed with 5 and 10 µl of whole blood was 88.2%
(

= 0.76; 95% CI, 0.63 to 0.89).
In all experiments performed with sera, the test results were
read after 10 min. When whole blood was used, the results were
read after both 5 and 10 min. No difference in the result was
observed, but the use of whole blood caused some staining in
the nitrocellulose paper which was less noticeable after 5 min
than after 10 min.
Reproducibility.
A second observer read the results of 739 ML Flow tests on serum samples, and the results were compared with the results of the first reader. When reading results as positive or negative, the agreement was 96% (
= 0.90; 95% CI, 0.82 to 0.97). When reading the test results as negative, plus/minus, 1+, 2+, 3+, or 4+, 83% (616 results) were in agreement (
= 0.73; 95% CI, 0.69 to 0.77) and the remaining 17% (123 results) were read one step higher or lower than by the other reader.
Two other observers independently read the results of 539 ML Flow tests, and their results were compared with those of the first reader. The agreements were 94.4% for observer 1 (
= 0.82; 95% CI, 0.73 to 0.90) and 96.8% for observer 2 (
= 0.9; 95% CI, 0.81 to 0.98). In addition, the results were also read as negative, plus/minus, 1+, 2+, 3+, or 4+. Of 539 readings, 84.2% (
= 0.76; 95% CI, 0.70 to 0.81) and 79.2% (
= 0.66; 95% CI, 0.60 to 0.71) were in agreement. All the discordant readings were read only one step higher or lower than by our original reader.
Storage.
There was no change of activity of the ML Flow test strips when stored up to 1 year at 4 to 45°C. Storage of ML Flow test strips for 2 months tested at 55°C results in no detectable loss of activity. The detection reagent was stable for at least 1 year at 28°C or 3 months at 45°C.

DISCUSSION
The availability of semisynthetic PGL-I derivatives (
2,
10,
14,
15) has enabled the development and use of serological tests
for the detection of leprosy-specific antibodies. These assays
include ELISA, the gelatin particle agglutination test, the
ML Dipstick, and now the immunochromatographic strip test (ML
Flow test). The ML Flow test is the most rapid and easily applicable
assay.
We showed that the ML Flow test gave a good correlation with the ELISA results (91%;
= 0.77), that it can be used on finger prick blood and serum alike (
= 0.70), giving reproducible results in 5 to 10 min, and that the ML Flow test can be kept outside the refrigerator and is stable for at least 1 year at 45°C. The amount (5 to 10 µl) of whole blood used is not critical, meaning that heparin-coated capillary tubes can be used for blood collection and direct application.
As the ML Flow test is scored by visual inspection for staining of the antigen line, reading of the test is therefore subjective. Faint staining in the ML Flow test must be considered negative since the aim of the test is to detect people with a relatively high bacterial load. Still, the agreement observed between readers in the laboratory and in the field settings was good (96% and 94%, respectively) with
values above 0.8, representing an almost perfect agreement beyond chance.
All these factors make the assay very suitable for use at different levels of the health care system, including the primary health center.
Classification of leprosy patients for treatment purposes is mostly based on counting the number of lesions (less than 6 skin lesions, PB; 6 or more lesions, MB) (21), but this method is unsatisfactory and subject to error (11). In confirmed leprosy patients, high specific antibody levels in general signify a high bacterial index and the absence of specific antibodies signifies a negative bacterial index (16). Thus, after diagnosis of a leprosy patient, the antibody response to PGL-I can be used for the classification as MB or PB for treatment purposes (4).
The ML Flow test, like all other serological tests for leprosy, is not a diagnostic tool, as the majority of PB patients do not develop detectable levels of antibodies, but it can be used as a tool for classification after the initial diagnosis has been made based on clinical signs and symptoms. Correctly classifying leprosy patients will (i) make leprosy control more cost efficient by preventing overtreatment and (ii) prevent transmission by avoiding undertreatment of MB patients that could otherwise be a source of infection due to relapse (3). In our study population, the sensitivity of the ML Flow test to correctly classify MB patients was 97.4% (95% CI, 93 to 99). In the group of untreated PB patients studied, the seropositivity was 40% with the ML Flow test, which is rather high; the seropositivity in PB patients has usually been reported to be in the range of 15 to 30% (1, 7, 8, 18). Using ELISA as our "gold standard," we found the seropositivity in this particular group of samples to be 38%, which is not significantly different from the result of the ML Flow test.
The specificity of the ML Flow test based on the results of the total control group was 90.2% (95% CI, 87 to 93) or 86.2% (95% CI, 82 to 90) if individuals from an area of nonendemicity are excluded. The ML Flow test gave a positive result in 9.8% of 498 control sera and in 1.3% of the 158 controls from an area of nonendemicity, which was similar to results obtained with a parallel ELISA study (results not shown). This latter observation confirms the specificity of the ML Flow test, even when the percentage of positive results in the control groups from an area of endemicity (consisting of people who may have been in contact with the leprosy bacillus) was relatively high. We did not see higher seropositivity in the tuberculosis and Buruli ulcer patient groups, indicating that there is no cross-reactivity with the glycolipids from the mycobacteria responsible for these infections.
PGL-I-based serological tests cannot be used as screening tools in the general population since not every person that is exposed and develops antibodies to M. leprae will ultimately develop clinical disease (19). The ML Flow test is not proposed for the screening of the whole population in communities where leprosy is endemic. It was previously shown with ELISA that seropositive contacts of leprosy patients have a relative hazard of 8 to develop leprosy and 56.1 to develop MB leprosy compared to seronegative contacts (based on reference 12). The results clearly show that serology can be used as a tool for the identification of contacts of leprosy patients with a high risk of developing leprosy. Screening contacts of leprosy patients in order to find and follow up or treat those at increased risk of developing leprosy may ultimately prevent transmission.
In conclusion, the ML Flow test was developed as a simple, stable, and rapid tool for two applications: (i) for the correct classification of newly diagnosed leprosy patients and (ii) to identify those contacts of leprosy patients that have an increased risk of developing leprosy in future.
In order for the leprosy control programs to be successful, it is essential both to treat patients accurately and to ensure that transmission of this slow chronic disease is prevented. The ML Flow test could contribute to these aims.

ACKNOWLEDGMENTS
We are grateful for the financial support from The Netherlands
Leprosy Relief.
The fieldwork would not have been possible without the cooperation and financial, logistical, and technical support from the Instituto Evandro Chagas in Brazil. We thank David Ashford (Centers for Disease Control and Prevention, Atlanta, Ga.) and C. Harold King (Emory University School of Medicine, Atlanta, Ga.) for providing us with the samples from Buruli ulcer patients.

FOOTNOTES
* Corresponding author. Mailing address: KIT Biomedical Research, Meibergdreef 39, 1105 AZ Amsterdam, The Netherlands. Phone: 31 20 5665449. Fax: 31 20 6971841. E-mail:
s.buhrer{at}kit.nl.


REFERENCES
1 - Agis, F., P. Schlich, J. L. Cartel, C. Guidi, and M. A. Bach. 1988. Use of anti-M. leprae phenolic glycolipid-I antibody detection for early diagnosis and prognosis of leprosy. Int. J. Lepr. Other Mycobact. Dis. 56:527-535.[Medline]
2 - Brett, S. J., P. Draper, S. N. Payne, and R. J. Rees. 1983. Serological activity of a characteristic phenolic glycolipid from Mycobacterium leprae in sera from patients with leprosy and tuberculosis. Clin. Exp. Immunol. 52:271-279.[Medline]
3 - Buhrer-Sekula, S., M. G. Cunha, N. T. Foss, L. Oskam, W. R. Faber, and P. R. Klatser. 2001. Dipstick assay to identify leprosy patients who have an increased risk of relapse. Trop. Med. Int. Health 6:317-323.[CrossRef][Medline]
4 - Buhrer-Sekula, S., E. N. Sarno, L. Oskam, S. Koop, I. Wichers, J. A. Nery, L. M. Vieira, H. J. de Matos, W. R. Faber, and P. R. Klatser. 2000. Use of ML dipstick as a tool to classify leprosy patients. Int. J. Lepr. Other Mycobact. Dis. 68:456-463.[Medline]
5 - Cartel, J. L., S. Chanteau, J. P. Boutin, R. Plichart, P. Richez, J. F. Roux, and J. H. Grosset. 1990. Assessment of anti-phenolic glycolipid-I IgM levels using an ELISA for detection of M. leprae infection in populations of the South Pacific Islands. Int. J. Lepr. Other Mycobact. Dis. 58:512-517.[Medline]
6 - Chanteau, S., J. L. Cartel, P. Celerier, R. Plichart, S. Desforges, and J. Roux. 1989. PGL-I antigen and antibody detection in leprosy patients: evolution under chemotherapy. Int. J. Lepr. Other Mycobact. Dis. 57:735-743.[Medline]
7 - Chanteau, S., J. L. Cartel, J. Roux, R. Plichart, and M. A. Bach. 1988. Comparison of synthetic antigens for detecting antibodies to phenolic glycolipid I in patients with leprosy and their household contacts. J. Infect. Dis. 157:770-776.[Medline]
8 - Cho, S. N., R. V. Cellona, T. T. Fajardo, Jr., R. M. Abalos, E. C. dela Cruz, G. P. Walsh, J. D. Kim, and P. J. Brennan. 1991. Detection of phenolic glycolipid-I antigen and antibody in sera from new and relapsed lepromatous patients treated with various drug regimens. Int. J. Lepr. Other Mycobact. Dis. 59:25-31.[Medline]
9 - Cho, S. N., T. Fujiwara, S. W. Hunter, T. H. Rea, R. H. Gelber, and P. J. Brennan. 1984. Use of an artificial antigen containing the 3,6-di-O-methyl-beta-D-glucopyranosyl epitope for the serodiagnosis of leprosy. J. Infect. Dis. 150:311-322.[Medline]
10 - Cho, S. N., D. L. Yanagihara, S. W. Hunter, R. H. Gelber, and P. J. Brennan. 1983. Serological specificity of phenolic glycolipid I from Mycobacterium leprae and use in serodiagnosis of leprosy. Infect. Immun. 41:1077-1083.[Abstract/Free Full Text]
11 - Croft, R. P., W. C. Smith, P. Nicholls, and J. H. Richardus. 1998. Sensitivity and specificity of methods of classification of leprosy without use of skin-smear examination. Int. J. Lepr. Other Mycobact. Dis. 66:445-450.[Medline]
12 - Cunaman, A., Jr., G. P. Chan, and J. T. Douglas. 1998. Risk of development of leprosy among Culion contacts. Int. J. Lepr. Other Mycobact. Dis. 66:S78.A.
13 - Fine, P. E. 1982. Leprosy: the epidemiology of a slow bacterium. Epidemiol. Rev. 4:161-188.[Free Full Text]
14 - Fujiwara, T., and S. Izumi. 1987. Synthesis of the neoglycoconjugate of phenolic-related trisaccharides for the serodiagnosis of leprosy. Agric. Biol. Chem. 51:2539-2547.
15 - Gigg, J., R. Gigg, S. Payne, and R. Conant. 1985. The allyl group for protection in carbohydrate chemistry. 17. Synthesis of propyl O-(3,6-di-O-methyl-beta-D-glucopyranosyl)-(1-4)-O-(2,3-di-O-methyl-alpha-L-rhamnopyranosyl)-(1-2)-3-O-methyl-a. Chem. Phys. Lipids 38:299-307.[CrossRef][Medline]
16 - Klatser, P. R., S. N. Cho, and P. J. Brennan. 1996. The contribution of serological tests to leprosy control. Int. J. Lepr. Other Mycobact. Dis. 64:S63-S66.[Medline]
17 - Klatser, P. R., M. Y. de Wit, T. T. Fajardo, R. V. Cellona, R. M. Abalos, E. C. de la Cruz, M. G. Madarang, D. S. Hirsch, and J. T. Douglas. 1989. Evaluation of Mycobacterium leprae antigens in the monitoring of a dapsone-based chemotherapy of previously untreated lepromatous patients in Cebu, Philippines. Lepr. Rev. 60:178-186.[Medline]
18 - Roche, P. W., W. J. Britton, S. S. Failbus, D. Williams, H. M. Pradhan, and W. J. Theuvenet. 1990. Operational value of serological measurements in multibacillary leprosy patients: clinical and bacteriological correlates of antibody responses. Int. J. Lepr. Other Mycobact. Dis. 58:480-490.[Medline]
19 - Van Beers, S. M., M. Hatta, and P. R. Klatser. 1999. Patient contact is the major determinant in incident leprosy: implications for future control. Int. J. Lepr. Other Mycobact. Dis. 67:119-128.[Medline]
20 - Visschedijk, J., B. J. van de, H. Eggens, P. Lever, S. van Beers, and P. Klatser. 2000. Mycobacterium leprae-millennium resistant! Leprosy control on the threshold of a new era. Trop. Med. Int. Health 5:388-399.[CrossRef][Medline]
21 - W. H. O. Study Group. 1994. Chemotherapy of leprosy. Technical Report Series 847. World Health Organization, Geneva, Switzerland.
Journal of Clinical Microbiology, May 2003, p. 1991-1995, Vol. 41, No. 5
0095-1137/03/$08.00+0 DOI: 10.1128/JCM.41.5.1991-1995.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.
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[Abstract]
[Full Text]
-
Okenu, D. M. N., Ofielu, L. O., Easley, K. A., Guarner, J., Spotts Whitney, E. A., Raghunathan, P. L., Stienstra, Y., Asamoa, K., van der Werf, T. S., van der Graaf, W. T. A., Tappero, J. W., Ashford, D. A., King, C. H.
(2004). Immunoglobulin M Antibody Responses to Mycobacterium ulcerans Allow Discrimination between Cases of Active Buruli Ulcer Disease and Matched Family Controls in Areas Where the Disease Is Endemic. CVI
11: 387-391
[Abstract]
[Full Text]