The role of serum tryptase in the diagnosis and monitoring of pediatric mastocytosis: a single-center experience

Abstract

IntroductionIn children, cutaneous mastocytosis (CM) is considered to be a benign disease associated with mast cell mediator-related symptoms. However, systemic mastocytosis (SM) and anaphylaxis may also occur. Since the basal serum tryptase (bsT) level reflects mast cell burden, its determination is recommended in the diagnosis and follow-up.AimTo compare clinical presentation and the course of mastocytosis in children with normal and clearly elevated bsT levels as well as to assess its usefulness in the diagnosis and monitoring of the course of the disease.Material and methodsA retrospective analysis of 102 medical records of children with mastocytosis diagnosed and followed-up in the Gdansk Mastocytosis Center in 2014 was performed.ResultsMaculopapular CM (MPCM) was diagnosed in 91 (89.22%) children, diffuse cutaneous mastocytosis (DCM) in 7 (6.86%) and mastocytoma in 4 (3.92%). The presence of flushing and bullous lesions was more frequent in children with bsT levels > 20 ng/ml in comparison with those who had bsT ≤ 20 ng/ml (p = 0.002 and p = 0.03, respectively). Anaphylaxis occurred in 2 MPCM children with bsT levels in normal ranges. In all of the 3 children with persistently and clearly elevated bsT levels, bone marrow biopsy revealed no mast cells infiltrates corresponding to SM.ConclusionsAlthough mastocytosis children with clearly elevated bsT levels frequently develop mediator-related symptoms, the occurrence of anaphylaxis in this age group may be difficult to predict. In pediatric cases with suspected SM, the bsT level is one of the crucial parameters considered before the decision on bone marrow biopsy.

Immunophenotype of pediatric‐onset mastocytosis does not correlate with clinical course

“…One of the major limitations of study is the lack of basal serum tryptase level (bsT) measurement. bsT level is known to reflect mast cell burden and correlate with disease severity . As this test is not routinely done in our center, we could not correlate the immunophenotype with bsT.…”

“…Pediatric‐onset is usually only cutaneous, with MPCM being the most common form. Most children with mastocytosis remain asymptomatic throughout their lives or have sporadic attacks . Although the course of pediatric‐onset mastocytosis is variable, resolution of the skin lesions generally occurs by adolescence .…”

Elevated Serum Tryptase in Non-Anaphylaxis Cases: A Concise Review

“…Furthermore, within the latter group, those with more extensive disease (diffuse cutaneous mastocytosis), have higher tryptase levels than more limited disease (mastocytoma, maculopapular cutaneous mastocytosis) [17,18]. Children with cutaneous mastocytosis were more likely to have flushing symptoms and bullous skin lesions with hypertryptasemia [19].…”

Mastocytosis in practice of a family doctors

“…Рівень сироваткової триптази зазвичай підвищений. Перебіг захворювання у цих пацієнтів має схильність до хронічного, а підвищений рівень сироваткової триптази і залучення до патологічного процесу інших органів є предиктором розвитку системного М і ускладнень [8,9,22]. Указані симптоми шкірної форми М в дітей можуть виникати, як спонтанно так і під дією провокуючих факторів, що викликають дегрануляцію ТК.…”

“…Найбільш об'єктивним показником в діагностичному алгоритмі постановки діагнозу дитячого М є визначення рівню триптази у сироватці крові (табл.1) [8,12,22]. Для верифікації системного М використовують діагностичні критерії ВООЗ: великий критерійщільна інфільтрація ТК (по 15 і більше клітин) в кістковому мозку або іншій тканині, окрім шкіри; малі критерії: 1) атипові ТК; 2) нетиповий фенотип ТК (CD25+ або CD2+); 3) рівень триптази в крові вище за 20 нг/мл; 4) наявність мутації в кодоні 816 c-KIT в клітинах периферичної крові, кісткового мозку або вражених тканинах.…”