Immunologic mechanisms in hypersensitivity pneumonitis: I. Evidence for cell-mediated immunity and complement fixation in pigeon breeders' disease

Immunologic studies were performed on 5 patients with pigeon breeders' disease. Intradermal injection of pigeon serum produced an immediate wheal-and-flare reaction within 15 minutes and a secondary Arthus-type reaction within 4 to 8 hours. Immunofluorescent studies of the secondary reaction site showed IgG, C3, and C4 in 2 patients. Patients' sera produced multiple precipitin bands with pigeon serum when reacted by double diffusion in gel. IgG antibody isolated from each of the patients' serum formed precipitating immune complexes that fixed large amounts of complement (C4) when added to fresh human serum. Peripheral blood lymphocytes from 4 of the 5 patients produced macrophage migration inhibitory factor (MIF) when challenged with dilute pigeon serum. These studies are the first to show complement fixing antibodies and macrophage MIF production by lymphocytes from patients with hypersensitivity lung disease and suggest that both humoral and cellular immunity may be important in the pathogenesis of these disorders.     

Monitoring of basophil activation using CD63 and CCR3 in allergy to muscle relaxant drugs

Allergic or pseudoallergic reactions that occur during anesthesia have been increasing for the last few years. To date, the diagnosis of allergy to muscle relaxants remains difficult. In this respect, we developed a flow cytometric method for the study of drug-induced basophil degranulation using CD63 and CCR3. Fifty patients who developed clinical features evocative of allergic reactions immediately after induction of anesthesia were included and classified into two groups. Group 1 (n = 39) comprised true allergic patients, who developed typical signs of shock associated to positive skin testing. Group 2 (n = 11) consisted of patients whose clinical history was not typical and skin testing was negative or nonconclusive. Seventeen control subjects were also studied in this report. We compared data from flow cytometry to skin tests, specific IgE, and histamine release results. Flow cytometry showed a sensitivity of 54%, while that of specific IgE was similar, at 62%. Interestingly, when considering the sensitivity of IgE + CD63 for diagnosis, we reached a sensitivity value of 80%. Of 15 negative results for specific IgE, we found 7 positive CD63 tests, while histamine release gave positive results in only 2 cases. Furthermore, the CD63 protocol showed good specificity (100%). We conclude that our flow cytometry protocol is a promising tool in allergy diagnosis since it is specific and complementary to specific IgE detection.     

Prediction of the average skin temperature in warm and hot environments

The prediction of the mean skin temperature used for the Required Sweat Rate index was criticised for not being valid in conditions with high radiation and high humidity. Based on a large database provided by 9 institutes, 1999 data points obtained using steady-state conditions, from 1399 experiments and involving 377 male subjects, were used for the development of a new prediction model. The observed mean skin temperatures ranged from 30.7 °C to 38.6 °C. Experimental conditions included air temperatures (T _a) between 20 and 55 °C, mean radiant temperatures (T _r) up to 145 °C, partial vapour pressures (P _a) from 0.2 to 5.3 kPa, air velocities (v _a) between 0.1 and 2 m/s, and metabolic rates (M) from 102 to 620 W. Rectal temperature (T _re) was included in the models to increase the accuracy of prediction. Separate models were derived for nude (clothing insulation, I_cl, ≤0.2 clo, where 1 clo=0.155 m² · °C · W⁻¹, which is equivalent to the thermal insulation of clothing necessary to maintain a resting subject in comfort in a normally ventilated room, air movement=10 cm/s, at a temperature of 21 °C and a humidity of less than 50%) and clothed (0.6 ≤ I_cl ≤ 1.0 clo) subjects using a multiple linear regression technique with re-sampling (non-parametric bootstrap). The following expressions were obtained for nude and clothed subjects, respectively: T _sk=7.19 + 0.064T _a + 0.061T _r + 0.198P _a− 0.348v _a + 0.616T _re and T _sk=12.17 + 0.020T _a + 0.044T _r + 0.194P _a − 0.253v _a + 0.0029M + 0.513T _re. For the nude and clothed subjects, 83.3% and 81.8%, respectively, of the predicted skin temperatures were within the range of ±1 °C of the observed skin temperatures. It is concluded that the proposed models for the prediction of the mean skin temperature are valid for a wide range of warm and hot ambient conditions in steady-state conditions, including those of high radiation and high humidity. Accepted: 7 February 2000     

Expression of a 32-kDa ligand for the CD40 antigen on activated human T lymphocytes

To identify the ligand(s) of the human CD40 antigen, a cDNA encoding the extracellular domain of the CD40 antigen was fused to a cDNA encoding the constant region (Fc) of human IgGl. The CD40-Fc fusion protein was able to specifically bind to CD4⁺ and various CD8⁺ T cell clones activated with immobilized anti-CD3. The ¹²⁵I-labeled CD40-Fc fusion protein bound anti-CD3 activated CD4⁺ T cell clone (MT9) with an equilibrium dissociation constant (Ka) of 10-20 nM. The human CD40-binding protein expressed on the cell surface of activated T lymphocytes is a monomeric protein of ≈ 32 kDa. Minor components of 29 kDa and 17 kDa were also detected. A small proportion of CD4+ and CD8⁺ blood mononuclear T cells activated by anti-CD3 expressed the CD40 ligand but its detection was best observed following depletion of B cells. Addition of B cells to purified T cells abolished the binding of CD40-Fc obtained after anti-CD3 activation.     

Effect of leukocyte hydrolases on bacteria

Leukocyte extracts, trypsin, and lysozyme are all capable of releasing the bulk of the LPS from S. typhi, S. typhimurium, and E. coli. Bacteria which have been killed by heat, ultraviolet irradiation, or by a variety of metabolic inhibitors and antibiotics which affect protein, DNA, RNA, and cell wall synthesis no longer yield soluble LPS following treatment with the releasing agents. On the other hand, bacteria which are resistant to certain of the antibiotics yield nearly the full amount of soluble LPS following treatment, suggesting that certain heatlabile endogenous metabolic pathways collaborate with the releasing agents in the release of LPS from the bacteria. It is suggested that some of the beneficial effects of antibiotics on infections with gram-negative bacteria may be the prevention of massive release of endotoxin by leukocyte enzymes in inflammatory sites.     

Pituitary corticotroph adenoma with crooke’s hyalinization

The diagnosis of pituitary corticotroph adenoma relies on the demonstration of a loss of the normal feedback control of adrenocorticotropic hormone (ACTH) biosynthesis by cortisol. The marked variability in the degree of ACTH suppression by glucocorticoids in these tumors, however, greatly enhances the difficulty in distinguishing Cushing’s disease from other syndromes of glucocorticoid excess. To illustrate this variability, we describe the clinical, biochemical, and morphological characteristics of a pituitary corticotroph adenoma in a 63-year-old woman, who presented with symptoms of a sellar mass but did not initially have florid Cushing’s disease. Light and electron microscopy of the pituitary tumor showed a corticotroph adenoma with Crooke’s hyalinization of the tumor cells, characterized by the accumulation of keratin immunoreactive microfilaments similar to those observed in normal corticotrophs in the presence of excess glucocorticoids. This case illustrates an unusual clinical presentation that may be associated with pituitary corticotroph adenoma showing Crooke’s hyalinization.     

Ultrastructural Changes Associated with Peripheral Neuropathy in HIV/AIDS

Light and electron microscopic studies were performed on neuromuscular biopsy specimens from 12 neurologically affected seropositive patients, 7 with the acquired immune deficiency syndrome (AIDS), 2 with AIDS-related complex, and 3 with no symptoms except for neuropathy. All patients had an axonal injury associated or unassociated with demyelination and peripheral neurogenic atrophy. Capillary lesions were consistently present, which seems to be a new finding. Moreover, tubuloreticular inclusions (TRIs) were found in endomysial (9 of 12 cases) and endoneurial (7 of 12 cases) vessels. Statistical analysis showed that TRIs in more than 20% of endomysial vessels correlated with a survival time shorter than 12 months (P = 0.028). Thus the quantification of TRIs seems to be one of the vital prognostic elements in this patient population.     

Evidence of a diverse T cell receptor repertoire for acetylcholine receptor,the autoantigen of myasthenia gravis

We utilized two methods to look for T cell clonal expansions in myasthenia gravis (MG). We analyzed TCRBV CDR3 length polymorphism (spectratyping) to look for evidence of clonal expansion of CD4 or CD8 T cells directly from peripheral blood of MG patients. No statistically significant differences were found between the diversity of TCR repertoires in MG patients compared to normal control individuals when analyzed as groups. Rare oligoclonal expansions were detected in some individual MG patients but the significance of these findings is unclear. Next, we analyzed a panel of T cell hybridomas from acetylcholine receptor (AChR) immunized, MG-susceptible HLA-DR3 transgenic mice. The epitope specificity, TCRBV gene usage and CDR3 sequences of these hybridomas were highly diverse. We conclude there is only limited evidence for restricted TCR repertoire usage in human MG and suggest this may be due to the inability of HLA-DR molecules to select for restricted TCR recognition of AChR epitopes.