Sensitization to rodents (mouse/rat) in an urban atopic population without occupational exposure living in Naples, Italy.

BACKGROUND: Until now no data on allergic sensitization to rodents allergens in Western Europe and Italy are available. The aim of this report was to investigate clinical significance and characteristics of IgE-mediated sensitization to mouse/rat (M/Rt) allergens in atopic subjects not occupationally exposed to these animals and living in urban area of Naples. METHODS: In 1765 consecutive outpatients, we selected all subjects with an immediate skin reaction to M/WRt dander clinical history including a carefijul evaluation ofthe modality of exposure, the results of skin-prick tests (SPTs) and specific IgE antibodies were recorded. RESULTS: Among 1185 SPT-positive patients, 22 were sensitized to M/Rt dander (respectively 1.60% and 0.59%). No patient was mono-sensitized Only three of 22 patients reported indoor conditions suggesting presence of rodents allergens at home. All patients exhibited low degree of SPT positivity and low levels of circulating IgE antibodies to M/WRt. Highfrequency of concomitant allergic sensitization to pet (and other animal) dander has been found. CONCLUSIONS: Our results suggest that role of allergic sensitization to rodents is negligible in atopic subjects without occupational exposure living in urban area of Naples. However, highly atopic individuals especially those already sensitized to common pet dander should be tested by SPTs/evaluation of serum specific IgE to rodents in the case they could begin an occupational exposure to M/Rt or keeping these animals as pets.

Respiratory allergy induced by exclusive polysensitization to serum albumins of furry animals.

In this report we describe un unusual case of exclusive allergic sensitization to furry animals, as a possible study model to speculate about different modalities ofsensitization to allergens of common and less common mammalian species. A 27-year-old woman referred in our Allergological Centre for the occurrence of conjunctival and severe respiratory symptoms after contact with several animals such as cats, dogs, rabbits, horses, cows etc. Patient underwent clinical and anamnestic evaluation including a detailed information on the modality of exposure to different furry animals. Skin-prick-test (SPT) was performed with our routine panel of commercial standardized extracts (Lofarma Laboratories, Milan, Italy). Some animal allergenic extracts (rabbit, horse, rat, mouse, cavia, cow and hamster) have been tested by SPT one week after the routine SPT A blood sample was taken for measurement of total IgE and specific IgE (CAP System, Phadia, Uppsala, Sweden) as well as Immunoblotting procedures. The results of in vivo and in vitro procedures revealed allergic sensitization only to animal-derived allergens. Total IgE were 59.3 kU/L. Immunoblotting showed a specific IgE-mediated sensitization of the patient to cow's, rabbit's and horse's serum albumins (SA). In conclusion, our case report confirms the role of SA as cross-reacting agent in allergic sensitization to furry animals. This finding suggests to perform SPTs to several furry animal allergens in all individuals with high level of allergic sensitization to common pets (cats and/or dogs) in order to identify allergy to other animals and consequently to avoid future exposures at risk.

Rabbit allergens: a significant risk for allergic sensitization in subjects without occupational exposure.

BACKGROUND: Although rabbits are becoming popular as pets, data about the characteristics of allergic sensitization to rabbit allergens in patients without professional exposure are scarce. AIMS OF THE STUDY: To determine the characteristics of allergic sensitization to pet rabbits, and the role of direct and indirect exposure to rabbits and rabbit allergens in non-professionally exposed patients. METHODS: From among 1124 consecutive outpatients, we selected all subjects with an immediate skin reaction to rabbit dander. A clinical history including a careful evaluation of the modality of rabbit exposure, the results of skin-prick tests (SPTs) and total/specific IgE antibodies were recorded. The prevalence of rabbit ownership in the Naples area was also calculated. RESULTS: Among 753 SPT-positive patients, 20 (2.65%) were sensitized to rabbit dander (5 patients were mono-sensitized). Fifteen patients reported direct rabbit contact (7 were rabbit owners and 8 had occasional contact outside the home); 3 patients had indirect exposure through contact with rabbit owners and 2 patients denied any direct or indirect exposure. Rabbit mono-sensitized owners of pet rabbits had persistent (moderate-severe) symptoms. The prevalence of rabbit ownership is 1.56%. CONCLUSIONS: In susceptible not professionally exposed individuals, direct rabbit contact and, in some cases, indirect or no apparent exposure, may induce allergic sensitization to rabbit allergens. A progressive increase in rabbit sensitization (also by indirect exposure) may be expected as a consequence of the increase in rabbit ownership.

The degree of serological sensitization to cat allergen in patients with or without cat at home.

BACKGROUND: The relationship between exposure to cat/dog in domestic environments and development of allergic sensitization to pet allergens is still controversial. OBJECTIVE: To test the role of indirect exposure to cat, we aimed to evaluate the amounts of cat specific IgE in sensitized subjects with or without cat at home. METHODS: Three hundred six adult patients with a previous diagnosis of allergic sensitization to cat allergens (by skin prick test) were enrolled for this study. Among 306 men and women sensitized to cat (and other allergens), 150 owned a cat for at least 10 years ( direct exposure) and 156 had never owned this animal (indirect exposure). An internal questionnaire specifically designed for the study was completed by the same allergists during the screening consultation: the results of skin prick tests, personal and clinical data, periods of symptoms and characteristics of cat ownership were carefully recorded. Specific IgE to cat extract was determined by the Pharmacia CAP System FEIA (Pharmacia Diagnostics, Uppsala, Sweden) and Immulite 2000 (Diagnostic Products Corporation, Los Angeles, USA) RESULTS: Although specific IgE to cat allergen were significantly higher in patients with cat at home (F = 42.77; p < 0.001), high amounts of these antibodies were found also in sera of subjects indirectly exposed to cats. DISCUSSION: The results of our study demonstrate that the degree of serological sensitization to cat allergens may be relevant also in subjects without any direct contact with cats (indirect exposure).

A multicenter evaluation of the CARLA system for the measurement of specific IgE antibodies vs. other different methods and skin prick tests.

The evaluation of specific IgE by using appropriate immunoassays represents a useful alternative diagnostic procedure where skin prick tests (SPTs) are not conclusive in clarifying the etiological role of suspected allergens. This study compares the results of the evaluation of specific IgE by using the CARLA system vs. other commercially available immunoassays (CAP system, Ala-STAT Medical system, ALLERgen IFCI Clone System) carried out on the same blood samples obtained from allergic/SPTs negative patients and vs. SPTs. We evaluated serum specific IgE produced against five selected allergens (Dermatophagoides pteronyssinus, Olea europaea, Parietaria judaica, Lolium perenne and Phleum pratense) by using these immunoassays and the correlations between the results of SPTs and IgE evaluations. We demonstrated a good correlation between these last parameters including a high degree of sensitivity and specificity. The reproducibility of the CARLA system was very high by comparing the results obtained by two different laboratories. The results of the CARLA system were well correlated to those of other well-known immunoassays such as CAP system and Ala STAT system. In conclusion, the CARLA system represents an efficient and reliable immunoassay for the evaluation of serum specific IgE.

Development of progressive kidney damage and myeloma kidney in interleukin-6 transgenic mice.

Interleukin-6 (IL-6) is a pleiotropic cytokine that has been postulated as playing a role in the pathogenesis of multiple myeloma, chronic autoimmune diseases, and alcoholic liver cirrhosis. We generated transgenic mice carrying a fusion between the mouse metallothionein-I (MT-I) gene promoter and the human IL-6 cDNA. MT-I/IL-6 transgenics express IL-6 constitutively in the liver and secrete the cytokine in the blood. They show initially activation of acute-phase response genes and accumulation of alpha 2- and beta-globulins in the plasma, which is followed by polyclonal hypergammaglobulinemia. MT-I/IL-6 transgenics die between 12 to 20 weeks of age. Histologic examination of transgenic animals at different ages and after necropsy showed, as expected from previous studies of IL-6 disregulation in vivo, an increase in the number of megakaryocytes in the spleen and bone marrow and, at later stages, IgG plasmacytosis in the spleen, lymph nodes, and thymus. However, no plasma cell infiltration was detected in other organs. The distinguishing feature of MT-I/IL-6 transgenics is the development of a progressive kidney pathology, in which the initial membranous glomerulonephritis is followed by focal glomerulosclerosis and finally by extensive tubular damage that reproduces the damage observed in patients at terminal stages of multiple myeloma (myeloma kidney). The pathogenetic role of IL-6 overproduction and of the resulting serum protein overload in the kidney damage is discussed.

T and B lymphocytes in patients with chronic active liver disease and in healthy HBsAg carriers.

E-rosette and surface Ig tests were used to study circulating T and B lymphocytes in 65 patients with chronic active liver disease (CALD), 15 healthy HBsAg carriers and 30 healthy controls. No significant variation in B lymphocytes was observed in CALD and in healthy HBsAg carriers. On the other hand, the absolute number and the percentage of T lymphocytes were significantly decreased in CALD, especially in cases negative for HBV infection markers.