J. Gooi

Mass Spectrometric Characterization of Circulating and Functional Antigens Derived from Piperacillin in Patients with Cystic Fibrosis

A mechanistic understanding of the relationship between the chemistry of drug Ag formation and immune function is lacking. Thus, mass spectrometric methods were employed to detect and fully characterize circulating Ags derived from piperacillin in patients undergoing therapy and the nature of the drug-derived epitopes on protein that can function as an Ag to stimulate T cells. Albumin modification with piperacillin in vitro resulted in the formation of two distinct haptens, one formed directly from piperacillin and a second in which the dioxopiperazine ring had undergone hydrolysis. Modification was time and concentration dependent, with selective modification of Lys541 observed at low concentrations, whereas at higher concentrations, up to 13 out of 59 lysine residues were modified, four of which (Lys190, Lys195, Lys432, and Lys541) were detected in patients’ plasma. Piperacillin-specific T lymphocyte responses (proliferation, cytokines, and granzyme B release) were detected ex vivo with cells from hypersensitive patients, and analysis of incubation medium showed that modification of the same lysine residues in albumin occurred in situ. The antigenicity of piperacillin-modified albumin was confirmed by stimulation of T cells with characterized synthetic conjugates. Analysis of minimally modified T cell-stimulatory albumin conjugates revealed peptide sequences incorporating Lys190, Lys432, and Lys541 as principal functional epitopes for T cells. This study has characterized the multiple haptenic structures on albumin in patients and showed that they constitute functional antigenic determinants for T cells.

Cutaneous granulomas associated with primary immunodeficiency disorders

Cutaneous granulomas are uncommon in primary immunodeficiency disorders. We report cutaneous granulomas in a child with ataxia telangiectasia (AT) and compare the clinical course with similar lesions in an adult with common variable immunodeficiency (CVI). A 4‐year‐old female with AT developed cutaneous granulomas as erythematous plaques. The largest lesion appeared on her left cheek and continued to progress despite treatment with topical and intralesional steroids. Disease control was obtained initially with oral antibiotics and low‐dose oral steroids. On cessation of oral steroids, significant relapse of the facial granuloma occurred. Pulsed and then oral steroids were required to stop the disease process leaving significant scarring. The second case is of cutaneous granulomas in a 66‐year‐old man, with CVI, who presented with an erythematous reticulate rash on the legs. We consider it useful to report this patient here as disease control was obtained in a similar way with systemic immunosuppression. In this patient a combination of oral steroids and azathioprine was used. These cutaneous granulomas are thought to be a manifestation of immune dysregulation. No infectious cause has been found so far. We recommend the use of broad‐spectrum antibiotics in conjunction with systemic steroids for progressive granulomas, as these patients are immunosuppressed and infection with an unidentified organism cannot be excluded.

Rapid desensitization for non-immediate reactions in patients with cystic fibrosis

Non-immediate hypersensitivity reactions to antibiotics in patients with CF represent a real-life challenge for clinicians. Desensitization is often performed in patients who have exhausted all therapeutic options. Whilst desensitization is an established procedure for immediate reactions we assessed the outcomes and safety of desensitization for non-immediate reactions. We retrospectively reviewed 275 desensitization procedures in 42 patients with a range of non-immediate reactions to six commonly used antibiotics. Desensitization was performed using a 7-step rapid intravenous protocol on a normal medical ward. 250 (91%) of overall desensitization procedures were successful; however, this figure incorporates certain individuals having multiple successful procedures. Individual patient success ranged from 55% with tazocin through to 88% with tobramycin. In the 25 patients who failed desensitization the reactions were mild and the majority occurred within 48 h of starting treatment. Prophylactic anti-histamines and steroids did not reduce the risk of reaction. Whilst the mechanisms remain uncertain we can confirm that rapid desensitization is a safe and effective way of re-introducing an antibiotic to a patient with a non-immediate reaction.

Complement membrane attack complex and hemodynamic changes during human orthotopic liver transplantation

Hemodynamic changes and elevation of intracellular calcium following reperfusion in human liver transplantation occur rapidly and do not match the time course of cytokine expression, therefore, we postulate involvement of other, pre‐formed substances, such as complement. We studied 40 adult patients undergoing liver transplantation. Blood was drawn for estimation of C3, C4, C3 degradation product, membrane attack complex, and CH100 levels and elastase (a marker of neutrophil activation) at induction of anesthesia, 5 minutes before reperfusion, 5 minutes and 60 minutes after reperfusion. Cardiac output was measured by thermodilution and systemic vascular resistance was calculated at these same time points. There was a significant rise in C5b‐9 membrane attack complex (P = .0012) with a corresponding fall in C3 (P = .0013) and C4 (P = .0002) levels and a rise in C3 degradation product levels (P = .0006). There was no significant change in CH100. These changes very closely followed the hemodynamic changes of a significant fall in systemic vascular resistance index (P = .0024) and increase in cardiac index (P = .0005). Elastase rose from 356 ± 53 to 557 ± 40 μg/L (P < .0001). There is complement activation and neutrophil activation at reperfusion in liver transplantation. Dilution alone cannot explain the fall in C3 and C4 levels as there is a corresponding increase in membrane attack complex and C3 degradation product levels with time. As both C3 and C4 are consumed, the classical pathway must be active, though alternative and lectin activated pathways may also be involved. These findings may, at least in part, explain the hemodynamic changes typically seen at reperfusion in liver transplantation. (Liver Transpl 2004;10:273–278.)

A child with laryngo-onychocutaneous syndrome partially responsive to treatment with thalidomide

Laryngo‐onychocutaneous syndrome (LOCS) is a condition characterized by erosive or ulcerative skin lesions associated with excessive granulation tissue, at sites of trauma such as the digits, elbows and knees. Similar lesions can occur within the conjunctival mucosa, leading to corneal scarring and blindness. The main complications, however, occur in the respiratory tract, where a similar process of erosions and subsequent formation of granulation tissue causes airway obstruction which may lead to premature death. LOCS is now believed to be a nonblistering variant of junctional epidermolysis bullosa and to date there are no efficacious treatments available. We report a 16‐year‐old girl with LOCS who failed to respond to methylprednisolone and cyclophosphamide, but had a partial response to oral thalidomide with marked decrease in granulation tissue and tracheal secretions. Interruption of treatment resulted in prompt resurgence of the granulation tissue which was again controlled by reintroduction of thalidomide. We propose that in the absence of effective therapies for LOCS, a trial of thalidomide in these patients should be considered.

Laryngo-Onycho-Cutaneous Syndrome

Laryngo-onycho-cutaneous syndrome (LOC) is a rare autosomal recessive genodermatosis characterized by altered cry at birth, skin erosions, nail abnormalities, and excessive granulation tissue in the conjunctivae and larynx. Shabbir first described this condition in 1986 in several affected individuals born to consanguineous families from the Punjabi regions of India and Pakistan. In 2003, the molecular basis of LOC syndrome was elucidated with the discovery of a unique mutation affecting the N-terminus of the α3 chain of laminin-332. In 2008, LOC syndrome was reclassified as a variant of junctional epidermolysis bullosa-other (JEB-O) and termed JEB-LOC. In this chapter, we provide an overview of the clinical features, pathogenesis, and management of LOC syndrome.

190 Elevated specific IgG against colomycin in patients with neurotoxicity

189 Peculiarities of the local immunity of intestine in children with cystic fibrosis T. Simanova1, A. Tsyganok1, A. Ozhegov2, L. Scheplyagina3, I. Kruglova3, N. Matveevskaya4. 1Republican Children’s Clinical Hospital, CF Centre, Izhevsk, Russian Federation; 2Izhevsk State Medical Academy, Izhevsk, Russian Federation; 3Federal Research Center of Pediatric Hematology, Oncology and Immunology, Medical University, Moscow, Russian Federation; 4Moscow Institute of Epidemiology and Microbiology G.N. Gabrichevskogo, Moscow, Russian Federation