INTERNATIONAL. JOURNAL OF LEPROSY Volume 50, Number 3Printed in the U.S.A.

Tear Lysozyme in Lepromatous Leprosy'Dhan Krishna Sen and Guatam Sarup Sarin 2

Lysozyme is of interest because of its an-tibacterial activity. It is most abundant innormal tears and the bulk of it is presumedto be synthesized locally. The concentra-tion of lysozyme in tears has been found tobe diminished in lupus erythematosusSjogren's syndrome ('''") and Herpes sim-plex keratitis ("). Although there is infor-mation on the concentrations of lysozymein the serum of leprosy patients ("), no re-port regarding its concentration in the tearsof such patients is available.

In this study, we have measured the con-centration of lysozyme in tears in leproma-tous leprosy patients and compared it withthat in the tears of healthy people.

MATERIALS AND METHODSThe study was carried out among 47 un-

treated lepromatous leprosy patients at-tending the Hansen Clinic of Lok Nayak JaiPrakash Narain Hospital, New Delhi. Thecases were diagnosed on the basis of theclinical picture, slit smear examination foracid-fast bacilli, and histopathological ex-aminations. The patients had a mean age of38.9 years (range 24 to 65 years). There were30 males (mean age 38.4 years; range 24 to60 years) and 17 females (mean age 40.7years; range 30 to 65 years). In 31 of themthe eyes were clinically normal and in theremaining 16 cases there was evidence ofactive anterior uveitis. Patients having dis-ease either in the eye or in any other partof the body other than lepromatous leprosywere excluded from this study.

Fifty healthy people of a similar age groupwere chosen consecutively from the Out-patient Department of Guru Nanak EyeCentre, New Delhi, to serve as controls.They had no evidence of ocular or systemicdisease and had attended the Eye Centre

' Received for publication on 28 December 1981;accepted for publication on 4 February 1982.

D. K. Sen, M.S., Associate Professor; G. S. Sarin,B.Sc., Senior Scientific Assistant, Department ofOphthalmology, Maulana Azad Medical College, LokNayak Jai Prakash Narain Hospital, and Guru NanakEye Centre, New Delhi, India.

mainly for the purpose of refraction. Theirmean age was 44.5 years (range 26 to 65years). There were 29 males with a meanage of 47.5 years (range 26 to 65 years) and21 females with a mean age of 40.4 years(range 26 to 53 years).

Tear samples were collected for normalpersons and leprosy patients by a methoddescribed earlier ( 5 ). The samples werestored at —20°C until assayed. Lysozymein the samples was quantified by a singleradial immunodiffusion method ("). Mono-specific rabbit anti-human lysozyme serumand the reference standard were commer-cially obtained from Behring Institute, WestGermany. The concentrations of lysozymein the tear samples were calculated fromthe calibration curve constructed by incor-porating three known concentrations ofstandard for every set of lysozyme deter-minations.

RESULTSHealthy individuals had mean tear lyso-

zyme concentrations of 1.34 mg/ml (TheTable). The differences between males andfemales were not statistically significant.Untreated lepromatous leprosy patients hadsignificantly lower tear lysozyme concen-trations (1.00 ± 0.10) than healthy controls(p < 0.01). The differences between thoselepromatous leprosy patients with evidenceof anterior uveitis and those with clinicallynormal eyes were not statistically signifi-cant.

DISCUSSIONThe "lysoplate — method of Bonavida and

Sapse ( 2 ) is commonly employed at presentfor the estimation of lysozyme concentra-tions in tear samples. This method is basedon the enzymatic action of lysozyme whichlyres the cell wall of Microcuccits /ysodeik-tiens. In this study, we have employed aradial immunoassay technique for estimat-ing lysozyme. The mean concentration oflysozyme in normal human tears by the ra-dial immunoassay technique is 1.34 mg/ml.It may be noted that this concentration is

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50, 3^ Sett Sarin: Tear Lysozyme in LL^

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THE TABLE. Tear lysozyme concentra-tions. Values are mean S.E.M.^ Intl.

Subjects Mean ± S.E.M. (N)

Health controls 1.34 ± 0.07 (50)Males 1.36 ± 0.10 (29)Females 1.31 0.10 (21)

Lepromatous leprosy patients 1.00 ± (1.10 (47)"Without anterior uveitis 1.01 -± 0.15 (31)With anterior uveitis 0.99 ± 0.11 (16)

p < 0.01, Student's t test compared to healthycontrols.

lower than the concentration (1.7 m« ml)reported by I3onavida and Sapse ( 2 ) in nor-mal human tears. This supports the conten-tion of Johansson and Malmquist ( - I) thatbacteriolytic lysozyme determination maynot be a specific enzyme assay and that thebacteriolysis is probably influenced to someextent by factors other than the lysozymeactivity.

Lepromatous leprosy causes widespreadchanges in different tissues of the body. Reaand Taylor (I) reported elevation of serumlysozyme in leprosy patients and attributedthis to increased production by the mono-cytic cells comprising leprous granulomas.Scheinberg, et al. ( 7 ) reported a trend to-ward higher serum lysozyme levels in lep-romatous leprosy patients compared withtheir control group. However, to the bestof our knowledge, no previous report isavailable on the concentration of lysozymein tears in patients with leprosy. We havefound that the lysozyme concentration intears of lepromatous leprosy patients is sig-nificantly low when compared with that inhealthy people. This low concentration inleprosy patients is probably due to a de-creased local production of lysozyme as aresult of subclinical structural changes inthe lacrimal gland and tubules caused bythe disease. Anterior uveitis is one of thecommon ocular afflictions of lepromatousleprosy but this per se did not appear toalter the lysozyme concentration in tears.

SUMMARYLysozyme concentrations have been es-

timated in 47 patients with lepromatous lep-rosy and in 50 healthy people by a singleradial immunodiffusion technique usingmonospecific antiserum against human ly-

sozyme. In healthy people the mean tearlysozyme concentration was 1.34 mg/ml. Inleprosy patients the mean tear lysozymeconcentration was 1.0 mg/ml. Anterioruveitis per se did not appear to alter thelysozyme concentration in tears.

RESUMENUsando una tecnica de inmunodifusiOn radial y un

antisuero monoespecitico contra lisozima humana, semidieron las concentraciones de la enzima en 47 pa-cientes con lepra lepromatosa y en 50 individuos sa-nos. En los commies sanos, la concentraciOn mediade lisozima en lagrimas file de 1.34 mg/ml, en tantoque en los pacientes esta foe de 1.0 mg/ml. La uveitisanterior por si misma no pareciO alterar la concentra-cion de lisozima en lagrimas.

RESUMEChez 47 malades atteints de lepre lepromateuse, et

chez 50 temoins normaux, on a estime les concentra-tions de lysozyme all moyen de techniques d'immuno-diffusion radiate utilisant tin antiserum monospeciliquecontre la lysozyme humain. Chez les personnes nor-males, la concentration moyenne de lysozyme dans leslarmes 6E10 de 1.34 mg/ml. Chez les malades atteintsde lepre, la concentration moyenne de lysozyme dansles larmes etait de 1.0 mg/ml. Une uveite anterieuren'apparait pas en soi comme une cause d'alt6ration dela concentration du lysozyme dims les larmes.

Acknowledgment. 'Minks are due to Dr. Ratan Singh.Professor of Dermatology, Maulana Azad MedicalCollege, New Delhi, for permitting us to conduct thisstudy on his cases.

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