Clinical diagnosis
Case 147
【Progress】
Two days after admission, purpura appeared in the dorsal skin of bilateral feet. Laboratory data 3 days after admission; D dimer still elevated to 24.4μg/mL: XIII factor 56 %. She was given steroid treatment. Her sister also previously experienced to be admitted two times in our hospital because of getting IgA vasculitis when she was in the first grade and the third grade of the elementary school.
【Discussion】
Vasculitis of the artery is largely categorized into large vessel vasculitis, medium vessel vasculitis and small vessel vasculitis. As representative examples, aortitis (Takayasu disease) belongs to the large vessel vasculitis. Polyarteritis nodosa and Kawasaki disease belong to the medium vessel vasculitis. ANCA associated vasculitis (microscopic polyangiitis, granulomatosis polyangiitis, eosinophilic granulomatous polyangiitis) and IgA vasculitis belong to small vessel vasculitis.
IgA is one of the immunoglobulins in human which is produced by B cell. IgA exists in mother’s milk, respiratory tract and digestive tract. It is believed that IgA is a key player for mucosa immune system to protect our body from the attack of virus and bacteria. Lowering of IgA concentration induces the body feel tired and makes the immune function weakened leading to be susceptible to catch cold. In short, when virus (adenovirus, rhinovirus, coronavirus) and bacteria (streptococcus, staphylococcus, streptococcus pneumoniae) invades the respiratory tract or the digestive tract, the opposed immune cells are M cells, B cells and T cells. M cells sample antigens and transport to the mucosa associated lymphoid tissue (MALT) and act a trigger or initiation of immune system. B cells alerted by M cells secret IgA and T cells alerted by M cells secret IgG, and leucocytes alerted by M and T cells infiltrate from blood and attack bacteria (1).
Allergic reactions are classically categorized into four types; Type 1, IgE mediated hypersensitivity (A, allergic anaphylaxis and atopy); Type 2, IgG mediated cytotoxic hypersensitivity (B, antiBody); Type 3, Immune complex (antigen-antibody) hypersensitivity (C, immune Complex): Type 4, Cell (mostly T cell) mediated hypersensitivity (D, delayed) (2). Although IgA vasculitis does not enter the classical category strictly, IgA vasculitis might be able to be categorized into subtype of Type 2 because it is a kind of antibody vasculitis (2).
IgA vasculitis formally called Henoch-Schoenlein purpura occurs following various infections such as β hemolytic streptococci, Helicobacter pylori and virus such as Hepatitis B, measles and mumps. These infections induce the production of abnormal IgA. Abnormal IgA combined with complement of component 3 (C3) deposits vascular wall, leading to vasculitis. It is unknown whether the main cause is overproduction of or decreased removal of abnormal IgA (2, 3).
Clinical manifestations of IgA vasculitis are 5 points; abdominal angina; digestive tract hemorrhage; hematuria; purpura with neither thrombocytopenia nor coagulopathy; Arthralgia and/or arthritis; less than 20 year-old. The presence of three or more of these indicators has an 87% sensitive for predicting IgA vasculitis (4, 5).
In our case, she was a five year-old girl and had abdominal angina, gastrointestinal duct hemorrhage and purpura, indicating four points of the five manifestations were found. Further, she had symptom got nasal fluid and cough a few days before and laboratory examination of stool revealed hemolytic streptococcal infection. Her sister had experienced IgA vasculitis twice, indicative of IgA relating to genetic proposition.
【Summary】
We present a five year-old girl suffering from tonsillitis and pharyngitis followed by abdominal angina, gastrointestinal duct hemorrhage and purpura. Laboratory examination revealed hemolytic streptococcal infection. She was given steroid treatment. Her sister had experienced IgA vasculitis twice, indicative of IgA relating to genetic proposition. It is borne in mind that IgA vasculitis belongs small vessel vasculitis and IgA vasculitis can be categorized into subtype of Type 2 because it is a kind of antibody vasculitis. IgA vasculitis formally called Henoch-Schoenlein purpura occurs following infections of β hemolytic streptococci, Helicobacter pylori and virus. Clinical manifestations of IgA vasculitis are 5 points; abdominal angina; digestive tract hemorrhage; hematuria; purpura with neither thrombocytopenia nor coagulopathy; Arthralgia and/or arthritis; less than 20.
【References】
1.Gross WL, et al.ANCA and associated diseases: immunodiagnostic and pathogenetic aspects. Clin Exp Immunol. 1993 Jan; 91(1): 1–12.
2.Michel BA, et al. (1992). "Hypersensitivity vasculitis and Henoch-Schönlein purpura: a comparison between the 2 disorders". Journal of Rheumatology. 19 (5): 721–8.
3.Rai A, et al. Henoch-Schönlein purpura nephritis. Journal of the American Society of Nephrology. 1999; 10: 2637–44.
2019.6.5