High burden of clonal mast cell disorders and hereditary α-tryptasemia in patients who need Hymenoptera venom immunotherapy.

BACKGROUND: In patients who require venom immunotherapy (VIT), there is a need to identify underlying mast cell (MC) disorders since these may affect the risk and severity of future sting reactions and the long-term effectiveness of VIT. METHODS: 1319 individuals with Hymenoptera venom allergy (HVA) who needed VIT from referral centers in Slovenia, Austria, Croatia, and Poland underwent examination for KIT p.D816V in peripheral blood leukocytes (PBL) using a highly sensitive PCR test and tryptase genotyping by digital droplet PCR. We also included 183 control individuals with large local reactions (LLRs) to Hymenoptera stings and with asymptomatic sensitization to Hymenoptera venoms. RESULTS: 285 of 1319 individuals recommended for VIT (21.6%) were positive for KIT p.D816V in PBL, preferably those who present with severe reaction (33.9% [n = 207 of 610] with Ring-Messmer grade 3-4 vs. 11% [n = 78 of 709] with Grade 1-2; p < .0001), whereas only 1.3% (n = 2 of 152) of controls with LLR and none with asymptomatic sensitization (n = 31) had KIT p.D816V. KIT p.D816V allelic burden was higher in those with severe reaction (median 0.018% [n = 207] in Grade 3-4 vs. 0.001% [n = 78] in Grade 1-2; p < .0001), and the majority had normal baseline serum tryptase levels (69% [n = 196 of 285]). All KIT p.D816V-positive individuals (n = 41) who underwent bone marrow (BM) biopsy were found to have underlying clonal diseases, principally BM mastocytosis. HαT was also associated with severe HVA and symptoms (p < .01), and remarkably, 31.0% (n = 31 of 100) were found to have concomitant KIT p.D816V. Concomitant HαT and KIT p.D816V showed an additive effect, and having both was associated with the highest risk for severe HVA, even higher than having either HαT or KIT p.D816V alone (OR = 3.8; p < .01). CONCLUSIONS: By employing prospective universal tryptase genotyping and examination for KIT p.D816V in PBL in large HVA populations, we have demonstrated a high burden of clonal MC disorders and HαT in patients who require VIT.

Foamy Macrophages in a Case of Mononucleosis With Amoxicillin-Induced Rash, Hyperlipidemia, and Hemophagocytic Lymphohistiocytosis.

ABSTRACT: A 38-year-old man presented with fever, cough, and jaundice. Four days before, he had started taking amoxicillin/clavulanic acid. He subsequently developed a morbilliform rash, and, according to clinical features and blood analyses, a diagnosis of mononucleosis with Epstein-Barr virus-associated antibiotic-induced exanthema and secondary hemophagocytic lymphohistiocytosis was made. A skin biopsy revealed a superficial perivascular lymphohistiocytic infiltrate with interface dermatitis and many foamy macrophages in the papillary dermis and around the vessels of the superficial dermal plexus. A blood lipid test uncovered marked hypercholesterolemia and hypertriglyceridemia. After treatment with dexamethasone and immunoglobulin, the skin rash, liver function, and lipid profile progressively improved. Xanthomatous cells have been observed in skin biopsies of acute graft-versus-host disease with liver involvement, and these cells have been suggested to represent a clue to the presence of hepatic disease. In our case, underlying cholestatic hepatopathy with hyperlipidemia was present. We believe that the incidental finding of foamy cells in graft-versus-host disease cases and in our case are likely related to the presence of severe liver disease with cholestatic hepatopathy and secondary hyperlipidemia in different background conditions.

Risk factors for severe sting reactions and side effects during venom immunotherapy.

Understanding the risk factors leading to severe systemic sting reactions (SSR) is crucial for initiating venom immunotherapy (VIT) and for educating affected individuals and their families. Some of these risk factors are well-established, some are no longer considered risk factors, and some remain controversial. Well-established risk factors for severe SSR include clonal mast cell disease, high baseline serum tryptase, and advanced age. The absence of skin symptoms and the rapid onset of symptoms are indicators of severe SSR. Recent publications indicate that antihypertensive treatment and stings in the head and neck area are not risk factors for severe SSR. VIT is the only available treatment that can potentially prevent further anaphylactic reactions. Although rare and generally manageable, individuals undergoing VIT may experience systemic adverse events (sAE). More sAE are expected in patients undergoing bee VIT compared to vespid VIT. The role of elevated baseline serum tryptase as a risk factor for sAE remains debated, but if it is a factor, the risk is increased by only about 1.5-fold. Rapid up-dosing protocols, depending on the specific regimen, can also be associated with more sAE. Severe initial SSR, antihypertensive medication, high skin test reactivity, and high specific IgE levels are not risk factors for sAE.

[Urethritis due to coinfection with Neisseria gonorrhoeae and Enterobius vermicularis in a 27-year-old man]. / Urethritis durch Koinfektion mit Neisseria gonorrhoeae und Enterobius vermicularis bei einem 27-jährigen Patienten.

Urethritis is mainly caused by sexually transmitted pathogens, such as Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) [1]. Close to 90 million adults are infected annually with NG [2]. Treatment shall be performed according to national guidelines and resistance profiles [2, 3]. Enterobius vermicularis (EV) is the most common helminth in humans with 1 billion people globally infected [4-6]. Symptoms include anal pruritus; however, many infections are asymptomatic [4-7]. A case of urethritis due to simultaneous infection with NG and EV is reported.