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Biomedical subjects

K Dellagi

Publications and source records attributed to K Dellagi.

At least 73 records · Page 4Linked to original sources

[Primary immunodeficiency in Tunisia: study of 152 cases].

BACKGROUND: Primary immunodeficiencies are rare immunopathological disorders. A multidisciplinary study group was set up in Tunis in 1988 and has since identified 152 cases of such diseases. We herein present our series and compare it to the international registries. POPULATION AND METHODS: Over a period of 8 years (April 1988-April 1996), 295 children suffering from recurrent infections were investigated; primary immunodeficiency was confirmed in 152 out of them. The immunological investigation included a study of specific and/or non specific humoral and cellular immunity. RESULTS: These 152 patients belonged to 129 families among which 70 were consanguine (54%). Familial primary immunodeficiency occurred in 23 of them. In 39 families (30%), one or more deaths occurred during early childhood. In more than half of the cases (89 cases), the immunological investigations revealed a cellular or combined immunodeficiency with a majority of ataxia-telangiectasia syndromes (53 cases), T cell activation immunodeficiencies (12 cases) and HLA class II deficiency (nine cases). A predominant antibody defect was observed in 35 patients with a majority of agammaglobulinemia (11 cases) and hyper-IgM syndromes (11 cases). A defect of non specific cellular immunity was found in 18 cases (11.8%) including seven cases of chronic granulomatous disease and five cases of leukocyte adhesion deficiency. Three children (1.9%) were deficient in the complement system. Deaths occurred so far in 37 patients (24.3%). CONCLUSIONS: Primary immunodeficiencies are relatively frequent in Tunisia, probably because of the high rate of consanguinity among the general population. The distribution of the different groups of primary immunodeficiencies is characterized by high frequency of ataxia-telangiectasia and hyper-IgM syndrome and scarcity of severe combined immunodeficiencies and Wiskott-Aldrich syndrome.

Child↗

[Interference of factor VIII excess on the detection of lupus anticoagulants by the activated partial thromboplastin time].

Antiphospholipids antibodies (AAP) were investigated in plasma of 62 patients with systemic lupus erythematosus, and studied for the possible interference of the excess in factor VIIIc-Von Willebrand factor (VWF-VIIIc) complex in the detection of lupus anticoagulants (LA) by the activated partial thromboplastin time (APTT). We used four commercial reagents and noted that each one exhibited a different level of sensitivity of LA; the most sensitive one allowed the detection of 16 LA positive plasmas while the less sensitive reagent detected only 6 positives. The Elisa test for IgG and IgM AAP detection was positive in 25 out of 62 plasmas (40%). Comparison of the Von Willebrand factor antigen level and the APTT values showed a significant negative corrélation with 2 reagents (r = 0.369, p < 0.01 and r = 0.272, p < 0.05 respectively) that were also the less sensitive to LA. The interference of an excess in VWF-VIIIc complex was further studied by the addition of purified factor VIII in 3 LA positive plasmas. Our results suggests that an excess of factor VIIIc could lead to false negative LA, using certain APTT reagents. We conclude that a more accurate LA detection require: sensitive reagents, a pool of normal plasmas selected with normal factor VIII level, as well as repeated testing of blood sampling withdrawn away of an inflammatory process to avoid false negative LA detection.

Adolescent↗

[Hemorrhagic syndrome and isolated alpha 2-antiplasmin deficiency. Apropos of a case].

An isolated alpha 2 plasmin inhibitor deficiency is reported in a 33 years old male, presenting repeated intramuscular hematomas since 5 years, spontaneously or after minor traumas. None of other family members were suffering from abnormal bleeding. Screening hemostatic examinations were normal except for a moderately shorted euglobulin lysis time (2 hours). Evaluation of fibrinolysis parameters (plasminogen, plasminogen activator inhibitor type 1, tissue plasminogen activator, fibrin and fibrinogen degradation products, alpha 2 plasmin inhibitor) showed normal values except for alpha 2 plasmin inhibitor which is markedly decreased (activity: 14%, antigen: < 5%). Familial hemostasis investigations have not been performed. This isolated alpha 2 plasmin inhibitor deficiency has been confirmed by two repeated control prelevments. Bleedings episodes were treated with antifibrinolytics agents (tranexamic acid). This case report shows the importance of the diagnostic approach in the laboratory to detect such rare hemostatic abnormalities associated with bleeding tendency.

Adult↗

New procedures and parameters for better evaluation of Androctonus australis garzonii (Aag) and Buthus occitanus tunetanus (Bot) scorpion envenomations and specific serotherapy treatment.

New procedures describing intoxication with variable amounts of scorpion venoms (from 1 to 5 LD50) allowed us to introduce new parameters to evaluate Aag and Bot envenomations. Significant differences between the fatal limit time (FLT) and the last mortality time (LMT) were observed when the amount of Aag and Bot venom injected was equal to 1 LD50 and equal to or higher than 2 LD50. For Aag and Bot, the percentage of the fast mortality (FM) and the delayed mortality (DM) varied conversely when the amount of injected venom increased from 1 to 5 LD50. The relationship between the venom LD50 (from 2 to 20), the median protective dose (PD50) and the neutralizing activity of specific antivenom have been established. PD50 increased in a parallel manner with LD50. The neutralizing titres (LD50/ml) of Aag antivenom decreased from 74 +/- 3 to 44 +/- 2 and that of Bot antivenom from 52 +/- 2 to 36 +/- 1 when the number of LD50 injected increased from 2 to 20. Antivenom potency was evaluated using different protocols based on the presence or the absence of preincubation of the venom with the antivenom. In experiments where venom and antivenom were simultaneously but immediately injected, PD50 were twice as high as those found when venom and antivenom were preincubated (30 min at 37 degrees C). On the contrary, the corresponding neutralizing titres were two times lower. In an attempt to simulate accidental envenomations and subsequent serotherapy, Aag and Bot venom (4 LD50) were subcutaneously injected and the appropriate PD50S of antivenom were intravenously administered at different time intervals after envenomation. When the time of antivenom administration was shorter than the FLT, all envenomed mice might be protected by increasing volume of antivenom. However, when the antivenom is injected closer to the FLT only 50 to 60% of mice envenomed, respectively, by Aag and Bot could be saved even when more than 5 PD50 were injected.

Animals↗

Recombinant BCG expressing the leishmania surface antigen Gp63 induces protective immunity against Leishmania major infection in BALB/c mice.

We have cloned and expressed the gp63 gene of Leishmania major in BCG to develop a recombinant vaccine against zoonotic cutaneous leishmaniasis. Two different expression systems were investigated. The first system consists of pAN, a Mycobacterium paratuberculosis promoter, which drives expression of ORF2, an open reading frame in IS900. This system allows the production of heterologous polypeptides as hybrids with the ORF2 gene product. The second expression system relies on the production of antigenic fragments as fusion proteins with the N-terminal region of Mycobacterium fortuitum beta-lactamase. Both constructs resulted in the production of Gp63 in BCG. The ability of the two recombinant BCG strains to induce protective immunity against a challenge with L. major amastigotes was evaluated after vaccination of susceptible (BALB/c), and resistant (C57BL/6) mice. Recombinant BCG producing Gp63 as a hybrid protein with the N-terminal region of the beta-lactamase elicited significant protection against a challenge with L. major in BALB/c-immunized mice.

Animals↗

A randomized, placebo-controlled trial in Tunisia treating cutaneous leishmaniasis with paromomycin ointment.

A randomized, placebo-controlled, double-blind trial was carried out in 1992 in central Tunisia to assess the tolerability and efficacy of paromomycin ointment against zoonotic cutaneous leishmaniasis caused by Leishmania major. One hundred fifteen patients, 2--60 years of age, with a single lesion of parasitologically confirmed cutaneous leishmaniasis, were included in the trial. The ointment was applied twice a day from day 1 through day 14. Clinical and parasitologic evaluations of lesions were done at days 0, 15, 45, and 105. Fifty-seven patients were allocated the treatment and 58 the placebo. Based on local toxicity and laboratory evaluation, there was no difference in tolerability between the two groups. Parasitologic evaluation at day 15 showed that 74.5% of the treated group had negative smears compared with 56.4% among controls (P = 0.06). This difference was no longer apparent at days 45 and 105. Clinical evaluation at days 15, 45, and 105 did not indicate any difference between the two groups. The clinical evaluation at day 15 was a good predictor of the final prognosis of the lesion in the two groups when analyzed separately, suggesting no clinical relapse in either group. These findings suggest that paromomycin ointment should not be used in the present formulation as a treatment for zoonotic cutaneous leishmaniasis in Tunisia.

Adolescent↗

[Spontaneous course of lesions of Leishmania major cutaneous leishmaniasis in Tunisia].

INTRODUCTION: The evolution of zoonotic cutaneous leishmaniasis (ZCL) caused by L. major, was usually described with crosssectional studies of patients under anti-leishmanial drugs. This work aimed to describe the clinical and parasitological status by a follow-up study of patients with ZCL and treated with a placebo. MATERIAL AND METHODS: In 1992, 58 patients with unique lesion of ZCL confirmed parasitologically and treated with vaseline twice a day for 15 days were followed in days 0, 15, 45 and 105. During every visit we have performed a clinical description of the lesion, a direct smear and a culture on NNN medium. RESULTS: 81 p. 100 of the lesions were ulcerated in day 0. A rapid clinical healing was noticed in 6.9 p. 100 of patients and the lesion remained active in 25.9 p. 100 of cases until day 105. Direct smears became negative among 56.4 p. 71 p. 100 and 92.3 p. 100 in days 15, 45 and 105 respectively. DISCUSSION: The ulcer was the most frequent sign during the diagnosis. The rapid conversion of positive parasitological tests suggest that the diagnosis of ZCL in endemic zones should be based mainly on clinical criteria.

Adolescent↗

Purification from Vipera lebetina (desert adder) venom of a protein that depletes human complement.

A rapid and efficient procedure for purification from Vipera lebetina venom of a low molecular weight anticomplement protein is described. The procedure used gel filtration on Superose 12, followed by ion-exchange chromatography on a Mono Q column. The purified protein migrated on SDS-PAGE as a single band of about 25,000 Da under nonreducing conditions and as a band of 16,000 Da under reducing conditions. Its isoelectric point was estimated to be 7.6 +/- 0.1. The isolated Vipera lebetina protein was found to decrease the hemolytic activity in human serum measured by assays for classical pathway and alternative pathway activation. The loss of the complement activity could be ascribed, at least in part, to a proteolytic cleavage of the alpha chains of C3 and C4. This protein was also found to be without action on human blood coagulation and on purified fibrinogen and Factor B.

Blood Coagulation↗

A unique mutation underlying carbonic anhydrase II deficiency syndrome in patients of Arab descent.

We have investigated, in the genomic DNA of ten Tunisian patients, the presence of a splice junction mutation at the 5' end of intron 2 in the carbonic anhydrase II gene (CAII) previously described in six CAII-deficient patients presumed to be of Arab origin. All our patients were homozygous for this mutation and were mentally retarded, a characteristic feature of the phenotype of patients with an Arabic background. This mutation is found exclusively in patients with an Arabic background and thus may be confined to this ethnic group.

Acidosis, Renal Tubular↗

Genomic and phenotypic diversity of Tunisian Theileria annulata isolates.

This study describes polymorphism in Theileria annulata, an intracellular protozoan parasite of bovine leucocytes and red blood cells. Fifty-three different stocks of T. annulata, isolated from 17 sites (districts) in Tunisia, have been characterized by anti-parasite monoclonal antibody (MAb) reactivity, glucose phosphate isomerase (GPI) isoenzyme electrophoresis, and Southern blotting with two genomic DNA probes. These appears to be considerable diversity amongst T. annulata stocks from Tunisia, no two isolates being identical, even those from animals on the same farm. Two distinct antigenic populations were detected by MAb 7E7. They were defined by negative and positive cells in the indirect fluorescent antibody test. The percentage of positive cells in different isolates ranged between 0 and 100%. The population variation seen by GPI analysis and DNA probes was greater; 7 different GPI phenotypes were identified amongst the stocks studied, while DNA probes T. annulata Tunis (TaT) 17 and 21 detected up to 5 different variants. The majority of isolates were shown to contain more than one parasite population, the number of variants per isolate ranging from 1 to 4. No correlation between particular parasite phenotypes or genotypes and their geographical site of isolation was observed. Selection of parasite populations in vivo and in vitro is also discussed.

Animals↗

Natural autoantibodies, IgG antibodies to tetanus toxoid and CD5+ B cells in patients with Mediterranean visceral leishmaniasis. The Leishmania Study Group.

Natural autoantibodies (NaAb) and IgG antibodies to tetanus toxoid (TT) were analysed in the sera of 38 children with active visceral leishmaniasis (VL) previously vaccinated with TT and in 30 healthy controls matched for sex and age. Patients exhibited high levels of NaAb to a panel of self antigens (tubulin, myosin, myoglobin, actin) contrasting to a low level of IgG to TT. Analysis of the circulating B cells in 26 untreated patients showed a low percentage of CD5+ per total B cells (3-66%, mean 36.6%) compared with 14 normal controls (17.8-66.6%, mean 52.7%) (P < 0.001). Evaluation of these parameters after antimonial therapy showed a significant decrease of the level of the NaAb (P < 0.0005), and a spontaneous increase of the level of the IgG to TT without any vaccine boosting (P < 0.01). In contrast, there was a significant increase in CD5+ B cells (P < 0.0005). This result suggests that CD5+ B cells may be sequestrated in parasitized lymphoid organs and may be released after remission. These findings show that the polyclonal B cell activation that occurs during active VL involves mainly B cells bearing NaAb and are in favour of a functional dichotomy of B cells.

Antibody Specificity↗

Identification of an immunodominant 32-kilodalton membrane protein of Leishmania donovani infantum promastigotes suitable for specific diagnosis of Mediterranean visceral leishmaniasis.

Sera from 35 patients suffering from Mediterranean visceral leishmaniasis (caused by Leishmania donovani infantum) and 59 patients with various forms of cutaneous leishmaniasis prevalent in the sub-Mediterranean countries (caused by Leishmania major, L. donovani infantum, or Leishmania tropica) were tested by immunoblotting and enzyme-linked immunosorbent assay (ELISA) with both membrane and soluble antigens prepared from L. donovani infantum parasites. Control sera were from healthy children (n = 41), adults with nonleishmanial diseases (n = 40), and patients with Chagas' disease (n = 12). A P32 antigen present in the membrane preparation from L. donovani infantum parasites was recognized by 95% of serum specimens from patients with Mediterranean visceral leishmaniasis but not by serum specimens from patients with cutaneous leishmaniasis or sera from control individuals. An ELISA with electroeluted P32 antigen was found to have a specificity and sensitivity of 94% in the serodiagnosis of Mediterranean visceral leishmaniasis. Healthy children with asymptomatic Leishmania infection were seronegative for the P32 antigen by ELISA. These results suggest that antibodies to P32 antigen develop only in patients with visceral leishmaniasis and that the P32 ELISA may be useful in areas where the disease is endemic for discriminating between patients with this disease and those with other clinical conditions.

Animals↗

Use of recombinant DNA probes for species identification of Old World Leishmania isolates.

Recombinant DNA probes from a genomic Leishmania major library were screened for their potential to distinguish among Old World Leishmania taxa by Southern blot analysis. A probe, pDK10, was selected and tested on a panel of 58 Old World Leishmania strains that had already been typed isoenzymatically; these strains belong to the different species described so far and had been isolated from various hosts and vectors in 14 countries. In the present study, 45 zymodemes were represented. Using the pDK10 probe, we were able to differentiate between the different phenetic complexes. No variations in hybridization patterns were found within these complexes. In addition, there was a good concordance between identification based on DNA hybridization with the pDK10 probe and that based on isoenzyme typing. The probe has been applied in identifying Leishmania strains that were isolated in Tunisia from humans, animals, or insects. Our results show that the application of the pDK10 probe, in combination with a Pst I digestion of Leishmania DNA, could be a possible alternative to isoenzyme analysis for the identification of Leishmania strains.

Animals↗

[Successful treatment of chronic active hepatitis with high-dose intravenous immunoglobulins in agammaglobulinemia].

BACKGROUND: Rapid progression of chronic active hepatitis can occur in patients with hypogammaglobulinemia. This report describes the successful use of i.v. immunoglobulins to treat chronic hepatitis in a child with agammaglobulinemia. CASE REPORT: A 17 month-old boy was admitted because he had suffered from recurrent infections since the age of 6 months. His family history was normal. Clinical and laboratory investigations showed hepatomegaly, agammaglobulinemia with absence of IgG, IgA, IgM and IgE, absence of beta cells, normal T cells, normal T cell proliferation and normal levels of complement, elevated ALAT (70 and 200 IU/ml) and ASAT (60 and 188 IU/ml). Liver biopsy showed typical features of chronic active hepatitis. The cause of this hepatitis (B and C virus, EBV, autoimmune markers) was not found. The patient was first given gammaglobulins (80 mg/kg) every week, subcutaneously, for 9 weeks, which did not change his transaminasemia. A second course of gamma-globulins, 400 mg/kg every 3 weeks, intravenously, for 6 months, resulted in a transient normalization of transaminases for 3 months. Definitive normalization was only obtained when the patient was given i.v. gammaglobulins (400 mg/kg/week) which gave a residual level of blood IgG of 10 g/l. This apparent cessation of hepatitis activity was confirmed by a second liver biopsy. The patient is now given i.v. gammaglobulins, twice a month, producing a residual blood IgG concentration of 5 g/l. CONCLUSIONS: The activity of this chronic hepatitis is closely correlated with the residual blood IgG concentration. Gammaglobulins could help neutralize virus extra-cellularly, although the viral origin of this hepatitis has not been-demonstrated.

Agammaglobulinemia↗

[Myoepithelioma (or myoepithelial cell adenoma). Report of a case].

One case of myo-epithelioma occurring in the parotid gland is reported. This tumor was composed of spindle cells. The diagnosis was confirmed by ultrastructural and immunohistochemical analysis demonstrating myofilaments aggregation pattern and positive staining for S100-protein and keratin antibodies. Of all salivary gland tumors, myo-epithelioma accounts for less than 1% of the total and has a good prognosis. Conservative surgical management is curative.

Adenoma↗