Cross-reactivities between date palm (Phoenix dactylifera L.) polypeptides and foods implicated in the oral allergy syndrome.

BACKGROUND: Date fruit and pollen antigens share a number of cross-reactive epitopes. Date pollen has been shown to cross-react with antigens from Artemisia, cultivated rye (Secale cereale), Timothy grass (Phleum pratense), Sydney golden wattle (Acacia longifolia) and Bermuda grass (Cynodon dactylon) pollen. The present study was carried out to examine any cross-reactivities between date palm polypeptides and antigens of some common foods and vegetables that have been implicated in the oral allergy syndrome (OAS). Because most of such cross-reactivities in other allergens are attributable to the presence of carbohydrate chains and profilin, their role was also investigated. METHODS: Fresh extracts of 20 common fruits and vegetables were prepared. Putative date profilins were isolated by affinity chromatography using a poly L-proline column. Date fruit extracts were digested by various endoglycosidases and the immunoglobulin (Ig)E binding of the postdigest products was assessed in immunoblots. Rabbit antisera to whole date fruit extracts, Timothy grass profilin and putative date profilins, as well as human sera from date sensitive individuals were used in immunoblotting, ELISA and in inhibition experiments. RESULTS: IgG, ELISA and immunoblot results with the different rabbit antisera and date-sensitive atopic sera showed several antigenic cross-reactivities and similar cross-reactivities were seen with birch, date and timothy grass profilins. IgE, ELISA and immunoblot experiments with pooled date sensitive human sera showed a range of cross-reactivities with some food extracts. A number of the IgE cross-reactivities could be inhibited after preabsorption of pooled sera with date extracts. Sixty-six percent of individual date hypersensitive human sera bound IgE in putative date fruit profilin and their pooled sera bound IgE in birch pollen profilin. IgE-binding of the endoglycosidase digested date fruit extracts to atopic serum pool was restricted to only a very low molecular weight band of 6.5-8 kDa. CONCLUSION: These results indicate that date palm polypeptides share cross-reactive IgG and IgE epitopes with a number of foods implicated in the oral allergy syndrome, bind to birch and Timothy grass profilins and bind IgE through glycosyl residues. The clinical relevance of these cross-reactivities needs to be further elucidated.

Cultivar-specific IgE-epitopes in date (Phoenix dactylifera L.) fruit allergy. Correlation of skin test reactivity and ige-binding properties in selecting date cultivars for allergen standardization.

BACKGROUND: Date fruits are allergenic and standardized extracts are required for diagnosis and therapy of this allergy. Since there are several cultivars of dates, this study was carried out to assess the allergenicity of different cultivars in order to select suitable source material for standardization. METHODS: The protein profiles of 18 of the most commonly sold varieties were compared by SDS-PAGE and their relative allergenicity assessed by SPT and IgE-based ELISA and immunoblotting. Thirty-two date fruit-sensitive patients were skin tested with a pooled extract from all the cultivars. Six of the patients with high SPT results (> or =3+) who volunteered were further tested with the 18 cultivars and their sera used in ELISA and immunoblotting. RESULTS: Six of the cultivars gave high SPT-positive reactions in > or =4 of patients. Five of these high SPT-reactive cultivars gave high IgE ELISA scores (> or =0.58) but individual cultivars varied in their number of IgE immunoblot bands. Cultivar-specific IgE-binding patterns indicated that only certain cultivars bound IgE at molecular weights of < or =14.3 and 27-33 kDa whilst all cultivars bound to a 54-58 kDa doublet. Cultivars that bind to the < or =14.3 and 27-33 kDa bands appeared to form the majority of the high SPT-reactive cultivars. When individual sera of 24 of the 32 SPT-positive patients were used in IgE immunoblots with the pooled cultivar extract, all sera bound IgE at < or =14.3 and 27-33 kDa and about 60% of sera bound to a 54-58 kDa doublet bands. CONCLUSIONS: These results indicate that allergenicity of date fruits is a cultivar-specific phenomenon. Sixty to 100% of sera from date fruit-allergic patients bind IgE to three major allergens of < or =14.3, 27-33 and 54-58 kDa. Five of the cultivars that evoke high SPT reactions, high IgE ELISA scores and bind IgE to the major allergens, can be selected for the preparation of 'in-house' allergen extracts and for allergen standardization.

Latex allergy in Saudi children with spina bifida.

BACKGROUND: Children with spina bifida (SB) are exposed to latex soon after birth during bladder catheterization, rectal disimpaction, and multiple surgical procedures. IgE-mediated latex-allergic reactions have been reported recently in these children. Our study was designed to assess the prevalence of allergic reactions to latex products in a group of Saudi Arabian children with SB in a tertiary care hospital. METHODS: Fifty-nine patients, aged 1-20 years, with SB were evaluated by a questionnaire on type of latex reactions; family and personal history of other allergic disorders, such as asthma, rhinitis, and urticaria; type and number of surgical procedures; and frequency of bladder catheterization and manipulation with latex materials. Confirmation of latex sensitivity was measured by skin prick test (SPT), CAP test, and latex skin challenge. RESULTS: Allergy to latex was detected in 25% of the study group. There was a significant variation in allergic reaction by sex (males 42%, females 12%) (P<0.01), use of catheters (yes 38%, no 13%) (P<0.05), and urologic surgery (yes 60%, no 18%) (P<0.01). The number of surgical procedures, age of patient, and V-P shunt were not significantly related to allergic reactions. CONCLUSIONS: Our findings support previous studies indicating a high prevalence of latex allergy among SB patients. The CAP test was a more sensitive measure of latex allergy in SB patients than SPT or latex challenge. There was significant correlation with urologic procedures and the use of urethral catheters.

Allergy to date fruits: characterization of antigens and allergens of fruits of the date palm (Phoenix dactylifera L.).

BACKGROUND: Date-palm (Phoenix dactylifera L.) fruits are eaten daily by most inhabitants of the Middle East and the neighboring countries. Recent reports have indicated that dates are allergenic. This study aimed to investigate the antigenic and allergenic potential of date fruits. METHODS: Date-fruit extracts from eight cultivars were evaluated in skin prick tests (SPT) in an atopic population, used to produce antisera, analyzed by SDS-PAGE, and fractionated by gel-filtration chromatography. Sera from SPT-positive individuals were evaluated by ELISA and RAST, and in anti-igE immunoblot experiments. RESULTS: About 13% of patients were SPT-positive for at least two extracts. SDS-PAGE of whole extracts revealed 15-18 protein bands of 6.5->100 kDa, and Sephacryl S-200 fractions gave distinct peptide bands. RAST and anti-IgE ELISA gave a range of positive results, which could be abrogated when sera were preabsorbed with fruit extracts. IgE immunoblots of different extracts with pooled positive sera revealed different anti-IgE-binding immunoprints. All the positive sera from fruit-allergic and pollen-allergic individuals bound strongly to two anti-IgE reactive bands of 6.5 to 12-14 kDa and 28-33 kDa, respectively, and about 50% of sera bound to a 54-58-kDa band. CONCLUSIONS: These results strongly indicate that 1) date-palm fruit is a potent allergen 2) sera from fruit-allergic as well as pollen-allergic patients recognize common fruit-specific epitopes 3) there is heterogeneity in patient responses to the different extracts.

Aeroallergens and viable microbes in sandstorm dust. Potential triggers of allergic and nonallergic respiratory ailments.

Aeroallergens and antigens in sandstorm dust, extracts of which were skin prick test (SPT) positive in allergic patients, were detected by rocket immunoelectrophoresis and ELISA. Fungi and bacteria isolated by agar settle plates and soil dilution and soil washing methods were enumerated and identified. Cat dander, Acacia, Alternaria, Aspergillus, Chenopodium, Cladosporium, Bermuda grass, Pithecellobium, Prosopis, Rumex, cultivated rye, and Washingtonia palm allergens were detected by both methods. Viable microbes including 1892 +/- 325 colony-forming units (cfu) of bacteria, and 869 +/- 75 cfu of fungi were isolated per gram of dust by the soil dilution method. Randomly selected microbial colonies on streaking and subculture were found to consist of between two and seven mixed colonies. Fungi including Alternaria, Aspergillus, Botrytis, Cladosporium, Mortierella, Mucor, Mycelia sterilia, Penicillium, Pythium, Ulocladium, Verticillium, and some yeasts were isolated. Actinomyces, Bacillus, Pseudomonas, and mostly coagulase-negative Staphylococcus species were identified, but the bulk of unidentified bacterial isolates were mainly mixed colonies of rods, cocci, coccobacilli, and some filamentous types. Six-hour agar settle-plate counts during sandstorms were 100 and 40% higher for bacteria and fungi, respectively, than without sandstorms. The most abundant aeroallergens were those of Acacia, Alternaria, Aspergillus, Bermuda grass, Cladosporium, cultivated rye, Prosopis, and cat dander. Pithecellobium dulce, Rumex crispus, and Washingtonia palm allergens were detectable for the first time in Riyadh. IgE reactivities of the dust in man were demonstrated by ELISA using sera from atopic, exposed, and normal subjects. These results indicate that sandstorm dust is a prolific source of potential triggers of allergic and nonallergic respiratory ailments, and the methods mentioned here should be routinely used for quick sampling of the environment.

Cultivar-specific epitopes in date palm (Phoenix dactylifera L.) pollenosis. Differential antigenic and allergenic properties of pollen from ten cultivars.

Pollen from ten staminate cultivars of the date palm (Phoenix dactylifera L.) were compared for their antigenic and allergenic potentials. Crude extracts from the various cultivars were tested in 6 atopic patients with confirmed allergy to date pollen in order to determine any differences or similarities in the antigenic and allergenic properties of these cultivars. Results of skin prick tests, ELISA, IgG and IgE immunoblot analyses, peripheral blood lymphocyte proliferation and concomitant interleukin-4 (IL-4) production indicated inter-cultivar heterogeneity. One of the cultivars, No. 8, failed to elicit any skin test reactivity or bind IgE in atopic sera as determined by ELISA, immunoblotting or any of the other parameters examined. However, there were individual differences in patient responses but in the main and contrary to the results obtained with cultivars No. 1, 2, 4, 5 and 8, five of the cultivars, namely No. 3, 6, 7, 9 and 10, showed more enhanced differential antigenic and allergenic properties. Our results strongly indicate that the antigenicity and allergenicity of date palm pollen is more of a cultivar-specific phenomenon than a species-specific phenomenon, which is governed by the number, quantities or both of the major allergen epitopes possessed by that variety or cultivar.

Cladosporium as an airborne allergen in Saudi Arabia.

Airborne mold monitoring in three cities in Saudi Arabia has documented the presence of Cladosporium in high concentrations. The spore counts reached threshold levels for sensitization at Jeddah and Al-Khobar with prominent seasonal variations. The concentration in Riyadh (central region) showed levels with minor fluctuationgs and a minor peak towards the month of Novermber. Indoor monitoring also revealed the presence of Cladosporium. Ten species of Cladosporium were idenified with C. sphaerospermum, C. herbarum, C. cladosporoides and C. macrocarpum being most prevalent. The species are relevant in relation to extracts for diagnosis. Skin testing of asthmatic children in Riyadh and Makkah revealed reactivities to Cladosporium extract of 5.8% and 31.3%, respectively. This indicates that Cladosporium may be an important allergen in the region that necessitates further biochemical and immunochemical studies to confirm the allergic impact of the species of Cladosporium prevalent in the region.

Chediak-Higashi syndrome: Report on five Saudi Arab children and review of the literature.

Five cases of the Chediak-Higashi Syndrome (CHS) among Saudi Arab children were diagnosed between June 1978 and December 1990. All patients were males, ages 18 months to ten years, born to first degree consanguineous parents. All showed the typical somatic and laboratory characteristics of this syndrome with characteristic hyperpigmented irides in four patients. Three patients were in the accelerated phase, two of whom responded to a combination chemotherapy (vincristine and prednisone) and one improved after splenectomy. All patients died before they passed the first decade of their lives. This report is the first detailed description of CHS among Arab children in the Arabian peninsula.

Partial albinism, immunodeficiency, and progressive white matter disease: a new primary immunodeficiency.

We studied 12 children who presented with a recently recognized syndrome. The salient features of this new syndrome were recurrent fever; hepatosplenomegaly; pancytopenia; blond, golden to silvery gray hair; hypopigmented skin, progressive white matter demyelination; and early death. Seven patients died, four with severe central nervous system (CNS) involvement, and three with bone marrow failure and sepsis. Cutaneous anergy to recall antigens was present in all patients. Other immunological abnormalities were poor antibody responses; deficient T-cell responses to phytohemagglutinin (PHA), concanavalin A (Con-A), and allogeneic lymphocytes; hyperresponsiveness of B lymphocytes to pokeweed mitogen; and variable phagocytic defects. Histopathologic examination of the hair and skin biopsies showed characteristic distribution of melanin with melanocytes present in normal numbers but with fewer short dendritic processes. Langerhans' cells were present in normal numbers in some patients and sparse in others. This syndrome seems to cluster into two tribes from two different geographical areas in the Arabian Peninsula. In the eight families studied, 12 other siblings and close relatives were found to be affected. The mode of inheritance in this syndrome is that of an autosomal recessive pattern. We propose the term "PAID syndrome" to identify patients with the above features.

Chediak-Higashi syndrome: clinical, hematologic, and immunologic improvement after splenectomy.

A 10-year-old boy with Chediak-Higashi syndrome in accelerated phase failed to respond to treatment with ascorbic acid, vincristine, and prednisone. Splenectomy resulted in clinical, hematologic, and immunologic improvement: his leukocyte chemotactic and phagocytic functions returned to normal. We suggest that splenectomy be considered in treatment of the accelerated phase of Chediak-Higashi syndrome unresponsive to other forms of therapy.

Wiskott-Aldrich syndrome.

Five cases of Wiskott-Aldrich Syndrome (WAS) were diagnosed in a tertiary care center in Saudi Arabia between 1981 and 1990. All five cases and two siblings (not reported here) had a history of rectal bleeding during the first week of life. Three of our patients were brothers. Two had classical Wiskott-Aldrich Syndrome and the third had the variant form of the syndrome. These two patients were successfully transplanted with allogenic bone marrow from their sisters. These two patients had complete engraftment with correction of both hematologic and immunologic abnormalities. Serum IgE returned to normal and their eczema cleared up. One patient died of intracranial hemorrhage. Two other patients had splenectomy. In these two splenectomized patients, platelet counts increased to normal values with no further bleeding. To our knowledge, this report is the first detailed description of WAS from Saudi Arabia.

Partial albinism with immunodeficiency: a rare syndrome with prominent posterior fossa white matter changes.

PURPOSE: To describe our experience in infants with partial albinism and immunodeficiency (PAID), a rare, recently recognized, probably autosomal recessive disorder. PATIENTS AND METHODS: Five infants suffering from this disease were examined with CT of the brain and four of these patients also underwent MR. Four of the five children also underwent follow-up CT or MR exams. RESULTS: Three of the patients followed with serial examinations demonstrated a rapid progress of white matter changes together with a loss of brain tissue over a few months. In all four patients subjected to follow-up, the posterior fossa white matter structures were severely involved during the course of the disease. CONCLUSIONS: This syndrome should be added to the list of demyelinating diseases, and should be kept in mind when white matter changes are prominent in the posterior fossa.

Cold urticaria in Saudi Arabia.

During an 8-year period we have seen two cases of cold-induced urticaria at the King Faisal Specialist Hospital and Research Centre, a major tertiary centre in Saudi Arabia. This indicates a lower prevalence in Saudi Arabia compared with other countries. One of our patients did not respond to cyproheptadine but she had an excellent response to ketotifen.

Acquired immunodeficiency syndrome in Saudi Arabia. The American-Saudi connection.

Two Saudi Arabian patients, one adult and one child, developed acquired immunodeficiency syndrome (AIDS) 2 1/2 and 3 1/2 years after blood transfusion. Both patients received blood imported from the United States in 1981. These are the first cases reported in Saudi Arabia. Since an undetermined number of Saudi patients have received blood imported from the United States, an outbreak of AIDS in Saudi Arabia might prove to be a serious problem in the near future. Measures such as limiting the importation of blood products from countries with a high incidence of AIDS and screening for human T-cell lymphotropic virus type III should be taken to stop the spread of this fatal disease.

Gastrointestinal malacoplakia in children.

Four children, whose ages ranged from 1 to 13 years, with malacoplakia of the gastrointestinal tract were treated at King Faisal Specialist Hospital between 1979 and 1983. All patients had either a preceding or a coexisting chronic illness. In one patient, malacoplakia was an incidental finding, while the remaining three patients presented with bloody diarrhea, abdominal pain, recurrent fever, and severe malnutrition. Colonoscopy in two patients revealed markedly inflamed and friable mucosa with focal ulceration alternating with patches of normal mucosa and pseudopolyposis. They were treated with antibiotics and cholinergic agonists. Three patients responded favorably, while one patient continued to have extensive active disease. Although the response to therapy is unpredictable, patients may respond if the treatment is continued on a long-term basis.