Immunologic tolerance: role of the regional lymph node.

Dansyl chloride, a skin setnsitizer when injected in complete Freund's adjuvant, induced marked tolerance and no sensitization when applied to the intact skin of guinea pigs. Application of this chemical to alymphatic skin islands failed to induce tolerance or sensitization. Lymnphatic connections between skin and regional lymph nodes were essential for the developmnent of ismmunologic toleance.

Calcium regulates parathyroid hormone messenger ribonucleic acid (mRNA), but not calcitonin mRNA in vivo in the rat. Dominant role of 1,25-dihydroxyvitamin D.

In vivo 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) decreased PTH and calcitonin gene transcription. A low calcium is the major signal for PTH secretion, and a high calcium for calcitonin secretion. We report here that calcium has no effect on calcitonin messenger RNA (mRNA) levels in vivo in the rat, but that a low calcium markedly stimulates PTH mRNA levels. Serum calcium was decreased by ip phosphorus and increased by calcium gluconate (ip or iv infusion) and demonstrated that a low serum calcium markedly increased PTH mRNA levels whereas a high serum calcium had no effect. There was no change in mRNAs for calcitonin or actin in the same thyroparathyroid extracts. After phosphorus ip serum calcium decreased from 10.4 to 8.5 mg/dl and PTH mRNA increased up to 3-fold at 1, 3, and 6 h. Gel blots showed that a low calcium increased PTH mRNA levels with no change in its size (833 base pairs). Calcitonin ip decreased both serum calcium and phosphorus with an up to 5-fold increase in PTH mRNA at 1 h, thus demonstrating that the effect of phosphorus on PTH mRNA was due to the low serum calcium and not the high serum phosphorus. When phosphorus and 1,25(OH)2D3 (100 pmol/100 g) were injected together, despite the low serum calcium, there was a decrease in PTH mRNA levels. These results show a linear relationship between calcium and PTH gene expression, but not calcitonin or actin, with a dominant role for 1,25(OH)2D3.

22-Oxacalcitriol does not interfere with parathyroid hormone-induced phosphaturia or cyclic-AMP excretion.

The vitamin D analogue, 22-oxacalcitriol [22-oxa-1,25(OH)2 vitamin D3], has pleiotropic effects similar to or greater than calcitriol but has markedly fewer calcemic and phosphatemic effects. To test the hypothesis that the lesser phosphatemic effect of 22-oxacalcitriol is due, at least in part, to a lack of interference with the phosphaturic effect of parathyroid hormone, acute clearance experiments were performed in parathyroidectomized rats receiving continuous 1-34 parathyroid hormone (PTH) infusion together with 22-oxacalcitriol (200 pmol.100 g body weight-1.min-1) or vehicle. In contrast to the previously reported inhibitory effect of calcitriol on PTH-induced phosphaturia, fractional excretion of phosphorus increased similarly in both groups, from 0.05 +/- 0.01 to 0.26 +/- 0.02 (p < 0.01) in the vehicle-infused animals and from 0.04 +/- 0.01 to 0.24 +/- 0.02 (p < 0.01) in the 22-oxacalcitriol-treated rats (p between groups not significant [n.s.]). Urinary cyclic AMP excretion also increased similarly, from 45.5 +/- 5.2 to 101.6 +/- 21.6 (p < 0.01) and from 45.4 +/- 5.6 to 102.6 +/- 16.7 pmol/min (p < 0.01), respectively (p between groups n.s.). In search for a nongenomic mechanism that might account for the disparate effects of 22-oxacalcitriol and calcitriol, OK cells, which are reminiscent of the mammalian proximal tubule cell, were stimulated with calcitriol and 22-oxacalcitriol and free intracellular calcium concentration was determined. At high concentrations, calcitriol caused a dose-dependent increase in [Ca2+]i; 22-oxacalcitriol had no effect on [Ca2+]i at any concentration.(ABSTRACT TRUNCATED AT 250 WORDS)

Treatment of primary Sjögren's syndrome with hydroxychloroquine.

Sjögren's syndrome is an autoimmune disease characterized by lymphocytic infiltration of the salivary/lacrimal glands, autoantibody production, and polyclonal hyperglobulinemia. In view of the efficacy and relative safety of hydroxychloroquine in other autoimmune disorders, the potential benefit of hydroxychloroquine (200 mg per day for 12 months) in 10 patients with Sjögren's syndrome was evaluated. Changes in levels of total immunoglobulin, antibody against Sjögren's syndrome-associated antigen B, rheumatoid factor, and in vitro production of immunoglobulin in the serum were evaluated. For comparison, 10 patients matched according to age and sex, who did not receive hydroxychloroquine were studied. In the hydroxychloroquine-treated group, the following observations were made: (1) significantly decreased total immunoglobulin G (IgG) and IgA levels with little change in IgM levels; (2) significant decrease in IgA-rheumatoid factor with a smaller decrease in IgM-rheumatoid factor; (3) decreased IgG anti-Sjögren's syndrome-associated antigen B autoantibody; and (4) decreased erythrocyte sedimentation rate and increased hemoglobin level. Further, a specific idiotype present on their rheumatoid factor (defined by monoclonal antibody 17-109) was significantly decreased, with disappearance of detectable circulating paraprotein in two hydroxychloroquine-treated patients. Finally, rheumatoid factor production in vitro by lymphocytes from hydroxychloroquine-treated patients using a T cell-dependent mitogen was significantly decreased. These results suggest that hydroxychloroquine modulates lymphoproliferation in patients with Sjögren's syndrome and may prevent progression to extraglandular sites of neoplastic transformation.

Successful renal transplantation from two donors with methanol intoxication.

Two patients with acute methanol intoxication are reported, one with acute renal failure. Both were declared brain-dead and kidneys were harvested at 80 and 130 hr after hospital admission. All four kidneys were transplanted and subsequently functioned well. In both donors who had received ethanol treatment, thrombocytopenia was present. The reluctance to use kidneys from such donors and from donors with acute renal failure before harvesting is discussed. Waiting lists for renal transplantation are growing and there is a world-wide shortage of cadaver organs. We were recently surprised to find reluctance to consider two local patients dying from methanol intoxication as suitable organ donors, and we report the outcome of four kidneys transplanted from these donors. We were unable to find any similar cases reported in the English literature.

Ocular findings in systemic cutaneous basophil hypersensitivity.

SCBH was induced by immunizing guinea pigs with a protein antigen and challenging 1 week later with a large intraperitoneal dose of the same antigen. Animals developed a delayed-onset, erythematous skin rash and dermal infiltration by basophils and eosinophils. The uveal tracts of these animals were infiltrated by eosinophils, as were several other internal organs. The eye is affected in SCBH, and as in other forms of ocular cell-mediated hypersensitivity, the eosinophil is a prominent cellular component of these reactions.

Langerhans cell alterations in the guinea pig cornea.

Langerhans cells (LC) are found in virtually all epithelial surfaces, but are rare or absent in the central cornea. LC migration into the cornea can be induced by several different stimuli. The authors studied LC in guinea pig corneal epithelium after: (1) suture placement; (2) suture removal; (3) UV-A irradiation; and (4) UV-C irradiation. Corneal LC markedly increased after suture placement during a 35-day observation period, and decreased by one-half during a 21-day observation period when sutures were removed. Suture-induced corneal LC decreased after UV-A irradiation, but increased after UV-C irradiation. These results demonstrate that ocular LC can be altered by nonimmunologic perturbations of the cornea.

Histopathology of delayed hypersensitivity reacitons in the guinea pig uveal tract.

Two distinct patterns of delayed-onset, cell-mediated hypersensitivity have been induced in the guinea pig eye with the same soluble protein antigen and two different methods of immunization. The predominant histologic feature of these reactions was the large number of eosinophils which infiltrated the uveal tract and the limbus. Skin test reactions in the same animals contained very few eosinophils and were typical of cutaneous basophil hypersensitivity or classic delayed hypersensitivity of the tuberculin type. It is suggested that local factors play a role in determining the character of immune expression in different tissues.

Immediate hypersensitivity in the guinea pig conjunctiva intravitreal and topical sensitization.

The right eyes of guinea pigs were injected with 1.5 mg sterile ovalbumin. Two months later, one drop of ovalbumin (approximately 0.6 mg) was applied to the conjunctiva of both eyes. All challenged eyes developed an immediate hypersensitivity reaction within 5 min. The reaction subsided within 2 hrs. Prechallenge antibody titers, as determined by passive hemagglutination, passive cutaneous anaphylaxis, and by an ELISA test were low. Titers rose rapidly after two conjunctival applications at weekly intervals. The hypersensitivity reaction was elicited each time antigen was applied to the conjunctiva of the intravitreally sensitized guinea pigs. Control guinea pigs received weekly conjunctival application of ovalbumin, without prior intravitreal sensitization. Most animals developed an immediate hypersensitivity reaction following the fourth application of the antigen. There was no detectable hemagglutinating or ELISA (IgG1, IgG2) antibody at the time the conjunctival reaction was first elicited. These experiments demonstrated that high circulating IgG1 or IgG2 antibody is apparently not necessary to initiate an immediate hypersensitivity reaction in the guinea pig conjunctiva. The authors also demonstrated that weekly topical application of ovalbumin sensitized guinea pigs for immediate hypersensitivity.

Treatment of herpes simplex keratitis with levamisole.

A model of chronic herpetic keratitis was developed by injecting rabbits subconjunctivally with a corticosteroid. A levamisole hydrochloride-treated group of these rabbits developed milder, more rapidly healing epithelial lesions than an untreated group. Although most of the untreated rabbits developed stromal disease, almost all of the lesions in the levamisole-treated animals were limited to the epithelium.

Tretinoin and corneal epithelial wound healing.

The entire corneal epithelium of each of 16 rabbits was removed bilaterally. Tretinoin (vitamin A acid) ointment was applied topically twice daily to the eyes of one half of the experimental animals, and the ointment base alone was applied to the eyes of the other half (the controls). On days 1, 2, and 3 after the removal of the epithelium, the healing of the denuded corneas of the animals receiving tretinoin was significantly (P = .01, .01, and .05, respectively) more advanced than the healing of the corneas of the control animals.

Herpes simplex keratitis treatment with vitamin A.

We produced chronic experimental herpetic keratitis by dropping PH-strain herpes simplex virus on scarified rabbit corneas and then injecting the rabbits subconjunctivally with low doses of corticosteroid (namely, triamcinolone acetonide suspension). Vitamin-A-treated rabbits developed milder, more rapidly healing epithelial lesions than untreated rabbits. Whereas most of the untreated rabbits developed moderate or severe stromal disease, most of the vitamin-A-treated rabbits developed only mild stromal disease or none at all.

Diagnosis of allergic conjunctivitis.

Itching was cited as a major symptom of their ocular disease by 49 (80%) of the 61 patients with allergic conjunctivitis. Conjunctival scrapings from 51 patients (84%) demonstrated intact eosinophils or eosinophil granules. Eosinophil granules were a useful and recognizable cytologic feature of allergic conjunctivitis even in the absence of intact eosinophils. We believe that a history of itching and the presence of eosinophils or eosinophil granules in conjunctival scrapings are helpful in diagnosing allergic conjunctivitis.

Natural and cloned human leukocyte interferon in herpesvirus infections of rabbit eyes.

Human buffy-coat interferon and a leukocyte subtype (LeIF-A) obtained by gene cloning in Escherichia coli were equally effective in ameliorating the course of herpetic keratitis in rabbits when applied topically at a daily dose of 0.5 X 10(6) units per eye for six days commencing one day before infection. When given intramuscularly at the same dose, there was no alteration in the course of the disease. Topical treatments with LeIF-A were equally effective in suppressing epithelial damage seven days after infection, regardless of whether treatment commenced one day before infection or two days after infection. However, treatment from the day before infection also caused a significant decrease in epithelial defect two days after infection.

Leukotrienes in the aqueous humor of patients with uveitis.

Utilizing chromatographic and radioimmunoassay techniques, we measured the concentration of leukotriene (LT) B4 and LTC4/D4/E4 in the aqueous humor of 14 patients with uveitis and seven patients undergoing penetrating keratoplasty or routine cataract extraction. Leukotriene B4 was detected in 11 of 14 patients with uveitis (mean, 0.96 pmole/mL), and LTC4/D4/E4 was found in 12 of 14 patients with uveitis (mean, 2.0 pmole/mL). In the control group, LTB4 was detected in six of seven patients (mean, 0.57 pmole/mL), and LTC4/D4/E4 was found in six of seven patients (mean, 1.9 pmole/mL). Leukotriene levels did not correlate with clinically assessed aqueous cell and flare. Mean levels of LT in patients with uveitis receiving corticosteroids were nearly double those found in non-steroid-treated patients. Despite apparent differences in LT levels, none of the above differences reached statistical significance.

Histopathology of corneal neovascularization.

We have developed an experimental model for the quantitative examination of the kinetics of the inflammatory cell response to thermal corneal injury. Using this model, we found a considerable difference in the type of inflammatory cell response to vasculogenic (peripheral) and nonvasculogenic (central) thermal cautery of the cornea. We found that infiltration of the corneal stroma with polymorphonuclear leukocytes preceded the growth of blood vessels in this model. This quantitative model will be useful in future studies of the role of inflammatory cells in different models of corneal neovascularization, and may provide quantitative evidence of how known inhibitors of corneal neovascularization exert their effect.

Ocular microbial flora in immunodeficient patients.

The eyes of 20 patients with primary immunodeficiency syndromes were examined, and microbial cultures of their lids and conjunctivae were made. Nine patients had a history of recurrent external ocular infections, and six of these had active blepharitis or blepharoconjunctivitis at the time of examination. A single pathogenic bacterium was isolated from the lids and conjunctivae of six patients with a history of infection; a mixture of two possible pathogens was cultured from eyes of three other patients. Three of the nine patients with infections had impaired B-cell and intact T-cell immunity, whereas three patients had impaired B cell and T-cell immunity. Two patients had chronic granulomatous disease in which a defect in phagocytosis was the predominant immunologic abnormality, and one patient (with mucocutaneous candidiasis) had intact B- and T-cell function at the time of testing. Although the immunodeficient patients had a higher incidence of lid or conjunctival infection than 20 age-matched controls, the microbial flora of the lids and conjunctivae did not differ between the two groups.

Ocular manifestations of Sjögren's syndrome: keratoconjunctivitis sicca.

As part of the triad of Sjögren's syndrome (SS), keratoconjunctivitis sicca (KCS) can be found in virtually all SS patients. This term emphasizes not only the reduced tear production but also the pathologic changes in the epithelial cells of the ocular surface. The symptoms of dry eye may vary from one patient to another depending on the severity of dryness, the ability of the diminished tear film to moisten the ocular surface, and the patient's tolerance for ocular discomfort. Treatment of the dry eyes is remarkably effective, and most patients benefit from moisturizing eyedrops to replace their own deficient tears. Major issues include the pathogenesis of decreased tear flow and ocular surface disturbances, as well as the roles of wound healing agents and anti-inflammatory medications in KCS therapy.

Conjunctivitis of allergic origin: clinical presentation and differential diagnosis.

Conjunctivitis of allergic origin is associated with a diversity of clinical presentations. Common features include pronounced itching, a milky conjunctival appearance, a stringy or ropy discharge and papillary hypertrophy of the tarsal conjunctiva in severe cases, and a family history of allergy. The diagnosis should be based on thorough history-taking and careful ophthalmic examination, and, when necessary, confirmation by laboratory testing. An IgE-mediated immediate hypersensitivity mechanism is associated with most types of allergic conjunctivitis, although contact allergy is mediated by lymphocytes rather than antibody. Treatment is based on the diagnosis and severity of signs and symptoms. An array of medications is available to control symptoms, and the regimen of choice should be based on the response to milder forms of therapy and consideration of drug side effects.

Retroviruses and their play-pals.

A 28-year-old man with a previous history of Neissena infection presented with diminished vision, disc swelling, and panuveitis. Serologic tests revealed positive titers for both HIV and syphilis. Current epidemiology and treatment of such cases are discussed.