Aukrust P, Müller F, Ueland T, Svardal A M, Berge R K, Frøland S S
University of Oslo, Oslo; University of Bergen, Bergen, Norway.
Eur J Clin Invest. 2000 Mar;30(3):252-9. doi: 10.1046/j.1365-2362.2000.00619.x.
Vitamin A has a broad range of immunological effects, and vitamin A deficiency is associated with recurrent infections. Common variable immunodeficiency (CVI) is a group of B-cell deficiency syndromes with impaired antibody production and recurrent bacterial infections as the major manifestations, but the immunological dysfunctions may also include T cells and macrophages. In the present study we examined the possible role of vitamin A deficiency in CVI.
We analysed plasma vitamin A levels in 20 CVI patients and 16 controls, and examined the relationships between vitamin A and clinical, immunological and metabolic parameters in CVI. In the six CVI patients with the lowest vitamin A levels we also studied the effect of vitamin A supplementation in vivo on several immunological functions in these patients.
(i) The majority of CVI patients had decreased vitamin A levels compared with healthy controls, as found in both cross-sectional and longitudinal testing. (ii) Low vitamin A levels were associated with the occurrence of chronic bacterial infections and splenomegaly as well as high neopterin levels. Decreased levels of carrier protein and malabsorption were not observed. (iii) Vitamin A supplementation in patients with low vitamin A levels resulted in increased interleukin-10 (IL-10) and decreased tumour necrosis factor-alpha (TNFalpha) levels, as found in both plasma and monocyte supernatants, possibly favouring anti-inflammatory net effects. (iv) Vitamin A supplementation in vivo also enhanced anti-CD40-stimulated IgG production, serum IgA levels and phytohaemagglutinin (PHA)-stimulated peripheral blood mononuclear cell (PBMC) proliferation.
A considerable subgroup of CVI patients appears to be characterized by low vitamin A levels. Our findings support a possible role for vitamin A supplementation in CVI, perhaps resulting in enhanced immunoglobulin synthesis and downregulated inflammatory responses.
维生素A具有广泛的免疫效应，维生素A缺乏与反复感染有关。普通可变免疫缺陷（CVI）是一组以抗体产生受损和反复细菌感染为主要表现的B细胞缺陷综合征，但免疫功能障碍也可能包括T细胞和巨噬细胞。在本研究中，我们探讨了维生素A缺乏在CVI中的可能作用。
我们分析了20例CVI患者和16例对照者的血浆维生素A水平，并研究了CVI患者中维生素A与临床、免疫和代谢参数之间的关系。在维生素A水平最低的6例CVI患者中，我们还研究了体内补充维生素A对这些患者多种免疫功能的影响。
（i）横断面和纵向检测均发现，与健康对照相比，大多数CVI患者的维生素A水平降低。（ii）低维生素A水平与慢性细菌感染、脾肿大以及高新蝶呤水平的发生有关。未观察到载体蛋白水平降低和吸收不良。（iii）维生素A水平低的患者补充维生素A后，血浆和单核细胞上清液中的白细胞介素-10（IL-10）水平升高，肿瘤坏死因子-α（TNFα）水平降低，这可能有利于抗炎净效应。（iv）体内补充维生素A还增强了抗CD40刺激的IgG产生、血清IgA水平和植物血凝素（PHA）刺激的外周血单个核细胞（PBMC）增殖。
相当一部分CVI患者似乎以低维生素A水平为特征。我们的研究结果支持在CVI中补充维生素A可能发挥的作用，这可能会增强免疫球蛋白的合成并下调炎症反应。
