Kazem Behbehani

An enzyme-linked immunosorbent assay using an arc 5 antigen for the diagnosis of cystic hydatid disease

We report on an easily standardized enzyme-linked immunosorbent assay (ELISA) for the diagnosis of cystic hydatid disease. The antigen used is commercially available, and purified to elicit an arc 5 precipitation line by immunoelectrophoresis (IEP) with sera of patients harbouring hydatid cysts. The IgG-ELISA was highly sensitive and specific, and of diagnostic value compared to total Ig-ELISA, IgM-ELISA or IgA-ELISA. When compared to the indirect hemagglutination test and to counterimmunoelectrophoresis using an arc 5 antigen, minimal cross-reactions were observed in sera of patients with a presumptive diagnosis of hydatidosis but none were observed in those harbouring intestinal helminths, schistosomes or filarial parasites. The assay is of low cost, simple to perform, and highly reproducible. The IgG-ELISA provides an unequivocal laboratory diagnosis of hydatidosis. It is eminently suited for accurate and early identification of hydatid disease patients, for instance in mass surveys, who may benefit immediately from currently available anthelmintics, thereby obviating the need for surgery later.

Induction, in vivo and in vitro, of macrophage membrane interleukin-1 by adjuvant-active synthetic muramyl peptides

Recent evidence has shown that a membrane form of interleukin-1 (IL-1) serves as a necessary signal for antigen presentation, leading to T-cell activation. The synthetic immunostimulant muramyl dipeptide (MDP) is known to induce secretion of IL-1 and its adjuvant effect was found to be mediated through enhancement of T-helper cells. We have investigated the ability of MDP and 19 other adjuvant-active or -inactive MDP analogs and derivatives to induce membrane IL-1 in mouse peritoneal macrophages. Enhancement in vitro of membrane expression and secretion of IL-1 in fresh or aged cultures of macrophages was observed after stimulation with MDP or with adjuvant-active but not with adjuvant-inactive muramyl peptides. Administration in vivo of adjuvant-active doses of MDP or of any of 12 other active analogs induced high levels of macrophage membrane IL-1 detected by the lymphocyte-activating factor assay. This effect was not observed when 7 other adjuvant-inactive derivatives were used. Moreover, under conditions where MDP did not exert an adjuvant effect, this immunomodulator was found to be incapable of inducing the expression of macrophage membrane IL-1. These results demonstrate a very high correlation between the ability to induce membrane IL-1 and the adjuvant activity of muramyl peptides. The correlation was observed irrespective of other biological effects of the synthetic adjuvants such as pyrogenicity and/or anti-infectious activity.

Cutaneous leishmaniasis in Kuwait.

During a study of cutaneous leishmaniasis, 33 patients from different districts in Kuwait were interviewed. Their lesions were examined clinically and microscopically. Most patients had multiple lesions (up to 60 per person), mainly distributed on the upper and lower limbs, and less frequently on the face, neck and trunk. Both sexes and all ages were affected. The incidence of the disease was recorded in most inhabited areas in Kuwait. The peak of incidence occurred in February.The data showed that cutaneous leishmaniasis is endemic in Kuwait. This is attributed to several factors including the central location of Kuwait in an area of the Middle East where cutaneous leishmaniasis is endemic (Iraq, Iran and Saudi Arabia), the rapid increase in economic activities, the number of travellers and immigrants, and the change in ecological conditions and nature of the habitat for the sandfly vectors following the rapid urbanization of certain districts.

Diagnostic value of anti-arc 5 IgG antibody and analysis of the IgG subclasses in sera of patients with cystic hydatid disease

Abstract Serodiagnosis of cystic hydatid disease (CHD) due to the metacestode of Echinococcus granulosus depends on detecting antibodies specific to hydatid antigen, but cross-reactivity with other parasites is one of the major draw-backs. We used a commercially-available antigen that elicits the arc 5 in immunoelectrophoresis and analysed the immunoglobulin class and the IgG subclass response by an ELISA. We tested sera from patients with confirmed CHD, cystic mass/lesions (CML) of non-hydatid origin, cysticercosis and healthy controls. High levels of antibodies to the hydatid antigen in all three classes (IgG, IgM and IgA) were observed only in the CHD patients. Significantly, only IgG antibody levels were discriminative and of diagnostic value. Also discussed is the validity of reading the significant cut-off point in IgG-ELISA in relation to a clinically important group of patients such as those with a CML of non-hydatid origin rather than healthy controls. Analysis of the anti-arc 5 IgG subclass responses demonstrated high antibody responses in all subclasses among the hydatid patients, with IgG3 the most discriminatory. The significance of the elevation of all four subclasses and more specifically of IgG4 in CHD is discussed in relation to certain biological activities of these immunoglobulin molecules.

Cystic hydatid disease: aspects of the incidence in man in Kuwait, Arabian Gulf.

Cystic hydatid disease (CHD) is endemic in Kuwait, but the exact extent of the disease in man has yet to be determined. The incidence was calculated by serological testing of sera from patients with a presumptive clinical diagnosis of hydatidosis and follow-up until the final diagnosis was determined. During a one-year period, 123 sera were received from two District General Hospitals serving a population of approximately 500,000. Eighteen patients had confirmed CHD, 17 were serologically positive in two tests, indirect haemagglutination (IHA) and counterimmunoelectrophoresis (CIEP), while another positive patient was identified through surgery and histopathology. These cases represent an estimated incidence rate of 3.6 per 100,000. Various factors, however, indicate that this is an underestimation of the true incidence. The infection rate of camels with hydatid cysts and dogs harbouring the adult worm, a possible measure of the true incidence in man, is considered high. Because of the nature of the population structure, the majority of patients were, in fact, non-Kuwaitis. Kuwaitis, who form 40% of the population, constituted about 30% of the CHD patients. Females were in the majority, the 21 to 50 yr. age-group being the most symptomatic. Hydatid cysts were most commonly present in the liver. Finally, compared to other countries at the time when a control programme was instituted, the incidence rate in Kuwait is moderate to high. However, the number of individuals with CHD does not appear alarming as the available capacity of the medical services is adequate.

Hydatid liver disease: problems in diagnosis in the Middle East endemic area

Imaging techniques such as ultrasound (US), liver scan and computerized tomography (CT) localize mass lesions in the liver and abdomen, and are valuable tools in the differential diagnosis of hydatid disease. However, we present two cases from Kuwait in the Middle East which demonstrate that these techniques alone are not as accurate as claimed in this geographical area. A sensitive and specific serological test is essential for a pre-operative diagnosis of hydatid disease. Discrepancies between radiological imaging and serological diagnosis are best resolved by cytology of the drained fluid and/or histopathological examination of the excised cyst. Negative serology would indicate ultrasound-guided aspiration of cyst fluid for cytological verification or enzyme immunoassay.

Induced malaria and antibody titres in acute infections and in blood donors in Kuwait

Concurrent with the increase in the number of imported cases of malaria into non-endemic Kuwait during the past 5 years, induced infections have been identified for the first time. We report 10 such cases over a 4-year-period. Of 8 transfusion-induced infections, 4 were due to Plasmodium falciparum and 4 to P. vivax. The mean incubation period for P. falciparum patients was 13 d and for P. vivax, 17 d. An accidental syringe-needle transmission and a congenital infection were due to P. falciparum and P. vivax respectively. Malarial antibody levels were assayed on commercially-available cultured P. falciparum schizonts by the indirect fluorescent antibody (IFA) test. To establish a base line, the sera of patients with blood film-confirmed P. falciparum and P. vivax were assayed. 96% of the P. falciparum sera were positive, the geometric mean titre (GMT) being 10,280. However, all sera from P. vivax patients were reactive but the GMT was lower at 505. 28% of sera from Kuwaitis and 45% of sera of a consecutive group of blood donors were also reactive, the respective GMTs being 38 and 51. The risk of transfusion malaria was calculated as 79 per million units drawn, an unacceptably high figure for a non-endemic country. We suggest a revised blood donor policy.

Autosomally inherited recessive spastic ataxia, macular corneal dystrophy, congenital cataracts, myopia and vertically oval temporally tilted discs. Report of a Bedouin family. A new syndrome

A Bedouin family is described with an unusual form of spinocerebellar degeneration. Spastic ataxia was found to be associated with congenital cataracts, macular corneal dystrophy and non-axial myopia, in the absence of retardation of somatic or mental maturation. Immunological abnormalities were common. Genetic analysis revealed that the pedigree is expressing the transmission and segregation of a single mutant autosomal recessive gene.

Analysis of the in vitro lymphoproliferative responses and antibody levels to the arc-5 antigen in patients with cystic hydatid disease

Using a commercially-available, purified, arc-5 antigen, we examined the in vitro proliferative responses of peripheral blood mononuclear cells from hydatid patients and from healthy controls. Antibody levels of different immunoglobulin classes were also measured against the same antigen, in sera of both groups. Our findings indicate that lymphocytes from healthy controls do not proliferate to the arc-5 antigen, whereas lymphocytes from the majority of patients do. The negative or weak responses observed among a few patients were not due either to increased release of prostaglandins in culture or to a lack of responsiveness to Interleukin-2. Antibodies of all three classes, G, M and A, measured by an ELISA, were elevated in sera of patients when compared with controls. However, only levels of specific IgG antibodies gave an excellent discrimination of the disease state and these were of diagnostic value. No direct or inverse correlations between lymphoproliferative responses and antibody levels were observed in either group, although a few patients with relatively low antibody titres demonstrated very high proliferative responses. The possible use of the proliferative assay as an adjunct to serology in the diagnosis of hydatid disease is indicated.

Specificity of counterimmunoelectrophoresis with an arc-5 antigen for the diagnosis of cystic hydatid disease

Abstract A rapid and simple counterimmunoelectrophoresis (CIEP) on a cellulose acetate membrane with antigen that elicits an arc-5 precipitin line in immunoelectrophoresis (IEP) is sensitive for the diagnosis of cystic hydatid disease (CHD). Specificity was proven by assaying the sera of patients with amoebiasis, schistosomiasis, filariasis, infections due to a variety of soil-transmitted nematodes and Taenia solium cysticercosis. Other sera analysed were from healthy controls, and patients with malignancies and conditions in which a space-occupying mass or lesion was presumed to be a hydatid cyst on ultrasound (US) and/or computerized tomography (CT). Compared to the indirect haemagglutination (IHA) test, the CIEP was almost 100% specific.