Objective To determine the clinical significance of measuring the levels of 25-(OH) vitamin D3 [(25-(OH) D3)],immune globulins and serum alkaline phosphatase(AKP) in children with recurrent community-acquired pneumonia(CAP).Methods Serum samples were collected in children with recurrent CAP (recur-rent CAP group,n =38),first CAP (first CAP group,n =123),and age matched normal children (heath control group,n =39).The 25-(OH) D3 level,IgG,IgM,IgA and AKP levels were measured.Results The serum 25-(OH)D3 concentration of the recurrent CAP group was (47.87 ± 2.28)nmol/L,that of the first CAP group was (84.43 ± 4.12) nmol/L,and that of the heath control group was (91.2 ± 7.85) nmol/L,the differences among the three groups were statistically significant (t =3.716,8.881,all P ＜0.05).The differences of the serum IgA concen tration among the three groups had statistically significant differences (t =4.596,5.319,9.230,all P ＜ 0.05).But the serum IgG concentration among the three groups had no statistically significant differences(t =1.115,1.887,1.090,all P ＞ 0.05).The serum IgM concentration among the three groups had no statistically significant differences (t =0.804,0.942,0.918,all P ＞ 0.05).The serum AKP concentration among the three groups had no statistically signifi cant differences(t =0.277,0.661,0.866,all P ＞ 0.05).The serum 25-(OH) D3 levels in 161 cases of CAP patients were not correlated to any of the levels of IgM,IgG,IgA,or AKP.Conclusion The levels of 25-(OH) D3 and IgA are significantly lower in children with recurrent CAP,indicating that vitamin D deficiency may play a role in the pathogenesis of recurrent CAP.Prophylactic use of vitamin D supplementation may improve the immune function and reduce the development of recurrent CAP in children.

Objective To investigate the relationship and clinical significance between the concentration of 25-hydroxy vitamin D3 [25-(OH)D3 ]in the serum and community-acquired pneumonia(CAP)in infants.Methods The study recruited 98 infants.There were 68 cases of mild pneumonia and 30 cases of severe pneumonia.The con-centration of 25-(OH)D3 in serum,IgA and alkaline phosphatase(AKP)were measured.33 infants who accepted physical examination in the outpatient department were selected as control group at the same time.Results The serum 25-(OH)D3 concentration of severe pneumonia was (21.09 ±7.32)ng/mL,mild pneumonia was (25.77 ± 8.06)ng/mL and the control group was (37.13 ±6.94)ng/mL.The differences among the three groups had statisti-cally significant differences(t =9.18,3.72,5.34,all P <0.05).The differences of serum IgA concentration among the three groups had statistically significant differences (t =5.42,3.96,8.92,all P <0.05).But serum AKP concen-tration among the three groups had no statistically significant differences(t =0.86,0.58,0.47,all P >0.05).The prevalence of Vitamin D deficiency was 40.0%,which was higher than mild pneumonia patients(20.6%)and the healthy children(9.1%)(χ2 =8.43,17.55,all P <0.05).Conclusion The serum 25-(OH)D3 concentration and IgA of CAP patients were lower than healthy children,especially in severe pneumonia cases.The prevalence of Vita-min D deficiency was significantly higher than healthy children.There were no relevance between the serum concentra-tion of 25-(OH)D3 ,IgA and AKP.25-(OH)D3 plays an important role in the development of CAP.The low level of serum 25-(OH)D3 concentration may be one of the risk factors and has correlation to the severity of pneumonia.