Anti-neutrophil cytoplasmic antibodies in new-onset systemic lupus erythematosus

Abstract: Background: The clinical significance of anti-neutrophil cytoplasmic antibodies in patients with new-onset systemic lupus erythematosus, especially in systemic disease accompanied by interstitial lung disease remains to be elucidated. Objectives: This study was designed to investigate the role of anti-neutrophil cytoplasmic antibodies in new-onset systemic lupus erythematosus patients. Methods: A hundred and seven patients with new-onset SLE were enrolled. Presence of anti-neutrophil cytoplasmic antibodies in the sera was assessed by indirect immunofluorescence as well as enzyme linked immunosorbent assay against proteinase-3 and myeloperoxidase. Clinical features and laboratory parameters of patients were also recorded. All patients were subjected to chest X-ray, chest high-resolution computed tomography and pulmonary function test. Results: Forty-five systemic lupus erythematosus patients (45/107, 42%) were seropositive for anti-neutrophil cytoplasmic antibodies. Compared with anti-neutrophil cytoplasmic antibodies-negative patients, the anti-neutrophil cytoplasmic antibodies-positive patients had significantly higher incidence of renal involvement, anemia, and Raynaud's phenomenon as well as decreased serum level of complement 3/complement 4 and elevated erythrocyte sedimentation rate. In addition, there was a positive correlation between serum anti-neutrophil cytoplasmic antibodies level and disease activity of systemic lupus erythematosus. Furthermore, prevalence of interstitial lung disease in the anti-neutrophil cytoplasmic antibodies -positive patients (25/45, 55.6%) was obviously higher than that in the anti-neutrophil cytoplasmic antibodies-negative patients (15/62, 24.2%). Study limitations: The sample size was limited and the criteria for screening new-onset systemic lupus erythematosus patients might produce bias. Conclusions: The level of anti-neutrophil cytoplasmic antibodies in new-onset systemic lupus erythematosus patients correlates positively with the disease activity and the prevalence of interstitial lung disease.

Myocardial ischemic post-conditioning protects the lung against myocardial ischemia/reperfusion-induced damage by activating GSK-3

Abstract Purpose: To investigate whether modulating GSK-3β could attenuate myocardial ischemia reperfusion injury (MIRI) induced acute lung injury (ALI) and analyze the underlying mechanism. Methods: Male SD rats were subjected to MIRI with or without myocardial ischemic post-conditioning in the presence or absence of GSK-3β inhibitor. GSK-3β inhibitor was injected peritoneally 10min before MIRI. Lung W/D weight ratio, MPO, PMNs, histopathological changes, TUNEL, Bax, Bcl-2, IL-6, IL-8, IL-10, GSK-3β, and caspase-3 were evaluated in the lung tissues of all rats. Results: After MIRI, lung injury was significantly increased manifested as significant morphological changes and increased leukocytes in the interstitial capillaries, Lung W/D ratio, MPO, and PMN in BALF, which was associated with enhanced inflammation evidenced by increased expressions of IL-6, IL-8 and reduced expression of IL-10. MIRI significantly increased cell apoptosis in the lung as increased levels of apoptotosis, Bax, cleaved caspase-3, and reduced expression of Bcl-2 was observed, which was concomitant with reduced p-GSK-3β. All these changes were reversed/prevented by ischemic post-conditioning, while these beneficial effects of ischemic post-conditioning were abolished by GSK-3β inhibition. Conclusion: Myocardial ischemia reperfusion injury induces acute lung injury by induction of inflammation and cell apoptosis. Ischemic post-conditioning protects the lung from ALI following MIRI by increasing p-GSK-3β.

Sclerotiorin is non-mutagenic and inhibits human PMNL 5-lipoxygenase and platelet aggregation.

Sclerotiorin, isolated from the fermented broth of Penicillium frequentans, exhibited potent inhibition against human polymorphonuclear leukocytes 5-lipoxygenase and human platelet aggregation with a half maximal value 36 µM and 250 µM, respectively. Further, the Ames test has demonstrated the sclerotiorin to be non-mutagenic.

Lesão pulmonar aguda induzida pela administração endovenosa de extrato da fumaça do cigarro / Acute lung injury induced by the intravenous administration of cigarette smoke extract

OBJETIVO: Investigar os efeitos agudos da administração endovenosa de extrato da fumaça do cigarro (EFC) em parâmetros funcionais respiratórios, inflamatórios e histológicos em ratos e comparar esse potencial modelo de lesão pulmonar aguda (LPA) com aquele com o uso de ácido oleico (AO). MÉTODOS: Foram estudados 72 ratos Wistar machos divididos em quatro grupos: tratados somente com soro fisiológico (SF; grupo controle); tratados com EFC e SF (grupo EFC); tratados com SF e AO (grupo AO); e tratados com EFC e AO (grupo EFC/AO). RESULTADOS: As médias de complacência foram significantemente menores nos grupos AO e EFC/AO (2,12 ± 1,13 mL/cmH2O e 1,82 ± 0,77 mL/cmH2O, respectivamente) do que no controle (3,67 ± 1,38 mL/cmH2O). A proporção de neutrófilos e a atividade das metaloproteinases 2 e 9 em lavado broncoalveolar foram significantemente maiores nos grupos AO e EFC/AO que no controle. O acometimento pulmonar avaliado por morfometria foi significantemente maior nos grupos AO e EFC/AO (72,9 ± 13,8% e 77,6 ± 18,0%, respectivamente) do que nos grupos controle e EFC (8,7 ± 4,1% e 32,7 ± 13,1%, respectivamente), e esse acometimento foi significantemente maior no grupo EFC que no grupo controle. CONCLUSÕES: A administração endovenosa de EFC, nas doses e tempos deste estudo, associou-se à LPA mínima. O EFC não potencializou a LPA induzida por AO. Estudos adicionais são necessários para esclarecer o papel potencial desse modelo como método de estudo dos mecanismos de agressão pulmonar pelo tabaco.

OBJECTIVE: To investigate the acute effects of intravenous administration of cigarette smoke extract (CSE) on histological, inflammatory, and respiratory function parameters in rats, as well as to compare this potential acute lung injury (ALI) model with that with the use of oleic acid (OA). METHODS: We studied 72 Wistar rats, divided into four groups: control (those injected intravenously with saline); CSE (those injected intravenously with CSE and saline); OA (those injected intravenously with saline and OA); and CSE/OA (those injected intravenously with CSE and OA). RESULTS: Mean lung compliance was significantly lower in the OA and CSE/OA groups (2.12 ± 1.13 mL/cmH2O and 1.82 ± 0.77 mL/cmH2O, respectively) than in the control group (3.67 ± 1.38 mL/cmH2O). In bronchoalveolar lavage fluid, the proportion of neutrophils was significantly higher in the OA and CSE/OA groups than in the control group, as was the activity of metalloproteinases 2 and 9. Pulmonary involvement, as assessed by morphometry, was significantly more severe in the OA and CSE/OA groups (72.9 ± 13.8% and 77.6 ± 18.0%, respectively) than in the control and CSE groups (8.7 ± 4.1% and 32.7 ± 13.1%, respectively), and that involvement was significantly more severe in the CSE group than in the control group. CONCLUSIONS: The intravenous administration of CSE, at the doses and timing employed in this study, was associated with minimal ALI. The use of CSE did not potentiate OA-induced ALI. Additional studies are needed in order to clarify the potential role of this model as a method for studying the mechanisms of smoking-induced lung injury.

Superoxide Anion Production by Human Neutrophils Activated by Trichomonas vaginalis

Neutrophils are the predominant inflammatory cells found in vaginal discharges of patients infected with Trichomonas vaginalis. In this study, we examined superoxide anion (O2(.-)) production by neutrophils activated by T. vaginalis. Human neutrophils produced superoxide anions when stimulated with either a lysate of T. vaginalis, its membrane component (MC), or excretory-secretory product (ESP). To assess the role of trichomonad protease in production of superoxide anions by neutrophils, T. vaginalis lysate, ESP, and MC were each pretreated with a protease inhibitor cocktail before incubation with neutrophils. Superoxide anion production was significantly decreased by this treatment. Trichomonad growth was inhibited by preincubation with supernatants of neutrophils incubated for 3 hr with T. vaginalis lysate. Furthermore, myeloperoxidase (MPO) production by neutrophils was stimulated by live trichomonads. These results indicate that the production of superoxide anions and MPO by neutrophils stimulated with T. vaginalis may be a part of defense mechanisms of neutrophils in trichomoniasis.

Myeloperoxidase deficiency in neutrophils of diabetic patients with and without infectious diseases

Myeloperoxidase [MPO], an iron-containing protein, is found in the azurophilic granules of neutrophils [PMNs], and catalyzes the conversion of hydrogen peroxide and chloride ions [Cl] into hypochlorous acid, which plays an important role in oxygen-dependent bacterial killing. The enzyme was first isolated in 1941, and deficiency of MPO was first described in 1954. Fewer than 5% of patients with MPO deficiency contract severe infections, which are usually fungal infections in diabetes mellitus [DM] patients. Besides the disorder in antifungal activity, diminished rate of bacterial [S. aureus] killing, and carcinogenesis, it seems that MPO deficiency is also related to atherosclerosis, degenerative neurologic diseases, as well as other disorders. In this study, we compared the levels of the MPO enzyme in the peripheral neutrophils of infected and non-infected DM patients at Imam Khomeini Hospital during 2005-2006. We compared these two groups the prevalence of MPO deficiency in each group, in order to then determine any correlations this may have with infection. In this case-control study, 50 patients were in the infected group [case group] and 50 were in the control group. Patients were chosen using simple sampling methods. Data was gathered from blood samples, using a qualitative test to determine MPO deficiency [Kaplow stain], laboratory results [BUN, Cr, PMN, HbA1c], interviews and completion of a questionnaires, as well as hospital records. Data were analyzed with SPSS software using T test and chi-square test, with a confidence index of 0.05. In spite of differences seen in stained slides, the MPO enzyme was positive in all of the patients, and no differences were seen between the two groups. The average patient age and the duration of DM in the case group were more than those of the control group. No statistical differences in the type of DM and glycosylated hemoglobin [HbA1c] levels were found between the two groups. Body mass indexes [BMI] and PMN counts were higher in the case group. The most prevalent infections were in the skin and soft tissue, bones and joints, as well as chronic respiratory infections [TB], pneumonia, urinary infections, CNS infections, gastrointestinal and intra-abdominal infections, mucormycosis, and sepsis. We found no correlation between MPO enzyme deficiency and age, sex, type or duration of DM, HbA1c levels and BMI

Effect of Cysticercus cellulosae fractions on the respiratory burst of pig neutrophils

Neutrófilos, eosinófilos e macrófagos são células que interagem com os parasitas no corpo do hospedeiro desenvolvendo atividade antiparasitária. A reação inicial destes leucócitos é a geração de espécies reativas de oxigênio (ERO) a fim de expulsar os parasitas. No presente trabalho estudou-se o efeito da fração total, de escolex e de membrana de Cysticercus cellulosae sobre a explosão respiratória de neutrófilos de suínos. A produção de peróxido de hidrogênio (H2O2) pelos neutrófilos incubados com as frações de C. cellulosae apresentou acréscimo de 190% (extrato total), 120% (escolex) e 44% (membrana). Alta atividade de catalase (33%, 28% e 28% para extrato total, escolex e membrana respectivamente) foi observada nos neutrófilos incubados com as frações de metacestodeo, podendo representar a própria proteção celular do neutrófilo. Frações de escolex e de membrana aumentaram a capacidade fagocitária dos neutrófilos (44% e 28%, respectivamente). Por outro lado, a fração total do cisticerco não alterou a capacidade fagocitária dos neutrófilos, o que pode estar relacionada com modificações na função da membrana celular causadas pela alta produção de ERO na presença da fração total. O extrato total de C. cellulosae é tóxico para os neutrófilos, indicada pela diminuição da capacidade fagocitária, provavelmente pela indução de alto nível de ERO. A diferença de toxicidade do extrato total, de escolex e de membrana para os neutrófilos pode ocorrer pelo efeito antigênico presente no fluido vesicular no extrato total de C. cellulosae.

Role of myeloperoxidase index in differentiation of megaloblastic and aplastic anemia.

BACKGROUND: Elevated neutrophil myeloperoxidase may have a role in the diagnosis of megaloblastic erythropoiesis. AIMS: To study the differentiating role of myeloperoxidase index in megaloblastic and aplastic anemia. SETTINGS AND DESIGN: The myeloperoxidase index (MPXI) was studied in 96 patients with megaloblastic and aplastic anemia diagnosed on bone marrow aspiration and biopsy examinations. METHODS AND MATERIALS: MPXI was measured with Technicon H1 (Bayer) automated analyzer. Nonparametric Mann-Whitney statistical test was used to compare the MPXI values between groups. RESULTS: The mean MPXI in megaloblastics and aplastic anemia was 18.3 and 1.8 (p< 0.001) respectively. MPXI> 20 denoted megaloblastic and MPXI <-11.6 denoted aplastic anemia. CONCLUSION: MPXI measurement may assist differentiation of megaloblastic from aplastic anemia, while MPXI> 20 rules out aplastic and MPXI <-11.6 rules out megaloblastic anemia.

Influence of Sex and Age on the Activity of Antioxidant Enzymes of Polymorphonuclear Leukocytes in Healthy subjects

In this study, the main antioxidant enzymes (AOE) of glutathione peroxidase (GPX), superoxide dismutase (SOD), catalase (CAT) and myeloperoxidase (MPO) were identified, and the influence of sex and age in healthy human polymorphonuclear leukocytes (PMNL) was determined. The SOD, GPX, CAT and MPO activities were investigated in intestinal parasite negative human PMNL from 109 healthy subjects aged from 6 to 70 years (55 males and 54 females) using simple and sensitive enzyme assays. Blood cells, such as eosinophils, platelets, neutrophils, monocytes, and macrophages also synthesize antioxidant enzymes (AOE). They constitute an important proportion and are also the major participants in a number of pathological conditions that suggest the involvement of AOE. A linear effect of age on SOD activity (p < 0.05) both in males and females was found. A similar effect with GPX activity (p < 0.05) was observed in males only. This showed that the activities of all these enzymes increase with age. In addition, SOD activity was significantly higher in females than males between the age of 19 and 70 years (p < 0.001). This analysis also showed that there is a negative correlation between the CAT-GPX (p < 0.05) activities and positive correlations between MPO-GPX (p < 0.05) activities only in females. No correlation among the other enzyme activities was found in either sex group. This study showed the activities of antioxidant enzyme activities and the correlations of these enyzmes activities with each other in healthy human PMNLs were age- and sex-dependent. This information may assisit in understanding the importance of antioxidant enzymes in the physiological and pathological conditions associated with PMNL.

Caracterización de la mielperoxidasa (MPO) y la fosfatasa alcalina granulocítica (FAG) en población infantil aparentemente sana / Characterization of the mielperoxidasa and the phosphate alkaline granulacitica in population apparently healthy

La actividad neutrofílica puede ser evaluada en el laboratorio a través de varias pruebas, entre las que se encuentran la estimación del contenido de la enzima mieloperoxidasa (MPO) y la determinación del score de fosfatasa alcalina granulocítica (FAG). Por esta razón se planteó establecer los rangos de referencia para ambas enzimas, en población pediátrica aparentemente sana de 6 a 10 años de edad. Así, se determinaron los rangos del contenido de la enzima mieloperoxidasa, encontrándose que los neutrófilos con contenido normal, alcanzan el 74 a 91 por ciento; con contenido moderado son de 7 a 21 por ciento, el 1 al 5 por ciento corresponde a neutrófilos con contenido escaso y el 0 al 1 por ciento presentan contenido nulo. Para la fosfatasa alcalina granulocítica se determinó un score promedio de 78, (rango de referencia de 52 a 103). Asimismo, se caracterizaron estas enzimas en algunos cuadros patológicos y se observó que, en algunos casos, se presentaron valores de MPO por encima del rango establecido (pacientes con infección respiratoria aguda y neumonía y con infección del tracto urinario), los demás procesos no presentaron modificación. Con respecto a la enzima FAG, se determinaron scores disminuidos en más de la mitad de las patología estudiadas, siendo hipotiroidismo, hepatitis B y un caso de enteroparasitosis, los que presentan valores drásticamente disminuidos; se observó un score significativamente elevado en el único caso de ITU estudiado. En desnutrición grado II, se determinó que ambas enzimas estaban disminuidas, a diferencia de desnutrición grado I, donde los valores establecidos se encontraban dentro del rango normal. Es importante continuar con la caracterización de ambas enzimas, aumentando el número de casos por patología, para confirmar los datos obtenidos

Inactivation of Trypanosoma cruzi dihydrolipoamide dehydrogenase by leukocyte myeloperoxidase systems: role of hypochloride and nitrite related radicals

Dihydrolipoamide dehydrogenase (LADH) from Trypanosoma cruzi, the causative agent of Chagas' disease, was inactivated by treatment with myeloperoxidase (MPO)-dependent systems. LADH lipoamide reductase and diaphorase activities decreased as a function of incubation time and composition of the MPO/H2O2/halide system, a transient increase preceding the loss of diaphorase activity. Iodide, bromide, thiocyanide and chloride were effective components of MPO/H2O2 or MPO/NADH systems. Catalase prevented LADH inactivation by the MPO/NADH/halide systems in agreement with H2O2 production by NADH-supplemented LADH. Thiol compounds (L-cysteine, N-acetylcysteine, penicillamine, N-(2-mercaptopropionylglycine) and Captopril prevented LADH inactivation by the MPO/H2O2/NaCl system and by NaOCl, thus supporting HOCl as agent of the MPO/H2O2/NaCl system. MPO/H2O2/NaNO2 and MPO/NADH/NaNO2 inactivated LADH, the reaction being prevented by MPO inhibitors and thiol compounds. T. cruzi LADH was affected by MPO-dependent systems like myocardial LADH, allowance being made for the variation of the diaphorase activity and the greater sensitivity of the T. cruzi enzyme to MPO/H2O2/halide systems.

Cuantificación de neutrófilos fecales mediante la determinacián de MPO (Mieloperoxidasa) en pacientes con diarrea invasiva / Quantify of fecal neutrophils by MPO (myeloperoxidase) determination in patients with invasive diarrhea

La mieloperoxidasa (MPO) es una enzima especifíca de los polimorfonucleares neutrófilos, la cual ha sido previamente usada para cuantificar elmnúmero de neutrófilos en tejidos, desde que su actividad se correlaciona linealmente con el número de neutrófilos. Con el objetivo de demostrar la presencia y realizar la cuantificación de leucocitos en materia fecal la MPO se disolvió en Bromuro de hexadeciltrimetilamonio y la actividad fue medida usando un ensayo de H2O2O-dianosid-ina. Se midió la actividad de MPO en 39 pacientes con diarrea producida por bacterias enteropatógenas y en 10 sujetos control. La presencia de leucocitos fue también determinada mediante la observación microscópica usando azul de metileno. La actividad de MPO fue positiva en 36 (92 por ciento) de los pacientes y la observació microscópica resultó positiva en 30 (77 por ciento). En los sujetos control la actividad de MPO fue indetectable y no se encontraron leucocitos en material fecal. En los pacientes la actividad de MPO en materia fecal tuvo un recuento de 1.6 a 2830 x 10(3) UMPO por gramo de heces (mediana: 46.0). El número de neutrófilos obtenido a través de la actividad de MPO tuvo un recuento de 6 a 13216.0 x mm(3) (mediana: 1261.0), la actividad fecal de MPO es una determinación bioquímica simple para la detección y cuantificación de leucocitos en materia fecal.

Activation domain in P67phox regulates the steady state reduction of FAD in gp91phox

An activation domain in p67(phox) (residues 199-210) is critical for regulating NADPH oxidase activity in cell-free system [10] To determine the steady state reduction of FAD, thioacetamide-FAD was reconstituted in gp91(phox), and the fluorescence of its oxidised form was monitored. Omission of p67(phox) decreased the steady state reduction of the FAD from 28% to 4%, but omission of p47(phox) had little effect. A series of the truncated forms of p67(phox) were expressed in E.coli to determine the domain in p67(phox) which is essential for regulating the steady state of FAD reduction. The minimal length of p67(phox) for for regulating the steady state of FAD reduction is shown to be 1-210 using a series of truncation mutants which indicates that the region 199-210 is also important for regulating electron flow within flavocytochrome b(558). The deletion of this domain not only decreased the superoxide generation but also decreased the steady state of FAD reduction. Therefore, the activation domain on p67(phox) regulates the reductive half-reaction for FAD, consistent with a dominant effect on hydride/electron transfer from NADPH to FAD.

Valores de fosfatasa alcalina leucocitaria en leucemia mieloide crónica / Score of leucocyte alkaline phosphatase in chronic myelogenous leukaemia

El objetivo de este estudio fue evaluar los valores de fosfatasa alcalina leucocitaria en pacientes con leucemia mieloide crónica en fase crónica, que concurrieron al Servicio de Hematología del Hospital Central de Mendoza. Se determinó en frotis de sangre periférica el score de la fosfatasa alcalina en los neutrófilos. Se utilizó el método semicuantitativo con hidrólisis enzimática del sustrato naftol fosfato, donde se libera naftol que se acopla a un azocolorante marcando el sitio de actividad de la enzima. Valor normal: 90 ñ 20. Se estudiaron 45 pacientes, 25 hombres y 20 mujeres con edades entre 18 y 75 años; la media y desviación estándar para la edad fue de 45 ñ 16 y para la fosfatasa alcalina 32 ñ 20. A 17 pacientes se les había realizado estudio citogenético, de los mismos resultaron cromosoma Philadelphia positivo el 94,1 por ciento, en éstos la media y desviación estándar fue para la edad 44 ñ 14 y para fosfatasa alcalina, 35 ñ 22, valores similares a los obtenidos en el total de los pacientes. La fosfatasa alcalina leucocitaria resultó mayoritariamente disminuida lo que concuerda con la bibliografía consultada

Cytochemical & ultrastructural alteration of cytoplasmic granules of rat peripheral blood neutrophils induced by chronic alcoholism & malnutrition.

The specific influence of malnutrition on the pathophysiologic changes induced by chronic alcoholism is controversial. In an attempt to determine and demarcate the effects of protein malnutrition from those produced by alcoholism and to evaluate the precise effect of alcohol per se on cytochemical and ultrastructural properties of rat polymorphonuclear neutrophil (PMN) granules, we investigated the influence of chronic protein malnutrition or chronic alcoholism alone and in combination, in rats. After a 4 month experimental period various PMN properties, such as cytochemical, morphometrical and ultrastructural, as well as neutrophil functions were studied. It was found that the degree of damage of PMNs induced either by ethanol or protein malnutrition alone was similar whereas their combination led to worsening of all markers of PMN functional ability. Ultrastructural changes of neutrophil granules including reduction, redistribution and atypical accumulation as well as appearance of autophagic vacuoles, confirmed their alteration which was emphasised by the additive pathophysiological interaction of alcoholism and chronic hypoprotein malnutrition.

Enzimas generadoras de especies reactivas del oxígeno: mieloperoxidasa / Enzimes generating reactive species from oxygen: myeloperoxidase

La defensa del organismo está mediada por las células del llamado sistema retículo endotelial, de las cuales los polimorfonucleares neutrófilos constituyen la primera línea de defensa inespecífica. La mieloperoxidasa es la proteína más abundante en los neutrófilos y es la única peroxidasa que cataliza la conversión del peróxido de hidrógeno y cloruro a ácido hipocloroso. Este es un potente agente oxidante que contribuye al mecanismo de defensa contra los agentes infecciosos; sin embargo, puede ser capaz de actuar sobre las células del hospedero en caso de activación incontrolable o excesiva e inactivar factores humorales. Dado el amplio espectro de reactividad, el ácido hipocloroso es un mediador de daño hístico en numerosos procesos inflamatorios. Se presentan algunas características físico-químicas, el mecanismo de reacción, la biosíntesis y la relación de la enzima mieloperoxidasa con diferentes procesos patológicos(AU) "

Alteration in the activities of the membrane-integrated enzymes of polymorphonuclear leukocytes in obesity.

Oubain sensitive and insensitive adenosine triphosphatase showed decrease in their activities in the polymorphonuclear leukocytes of obese patients while the activity of acetylcholinesterase was found to be increased significantly. The contents of sodium, potassium and magnesium were found to be significantly decreased in polymorphonuclear leukocytes of obese patients. Polymorphonuclear leukocytes obtained from treated obese patients showed considerable restoration.

Leucocyte alkaline phosphatase activity in patients with squamous cell carcinoma.

Alkaline phosphatase have been demonstrated histochemically in the cytoplasm of neutrophils. Altered LAP activity has been observed in a number of conditions. Increased values are found in various inflammatory lesions where as in different malignancies LAP falls. Our study was aimed to see the alteration in LAP activity in case of squamous cell carcinoma. The study was carried out in peripheral blood smears of 185 cases (110 cases of squamous cell carcinoma and 75 of normal persons). After histochemical staining, LAP scoring was done. LAP score in Squamous cell carcinoma (mean +/- SD = 57.41 +/- 16.9). No significant difference in LAP score was found according to the site and grade of carcinoma, and in relation to metastasis. 43 cases were followed up after variable periods of treatment. LAP score was found to be significantly raised following treatment, (mean +/- SD = 21.14 +/- 5.94, p < 0.001). It is concluded that LAP scoring might be used as a cheap and simple technique to diagnose occult malignancies and to assess the response to therapy.