Potter E V, Shaughnessy M A, Poon-King T, Earle D P
Infect Immun. 1982 Jul;37(1):227-34. doi: 10.1128/iai.37.1.227-234.1982.
Serum immunoglobulin A (IgA) was markedly increased in 80% of 50 patients with acute rheumatic fever in Trinidad in contrast to 20% of 63 patients with acute glomerulonephritis, whereas serum IgG was increased in nearly all of both groups. Since total antibody to M-associated protein (MAP) (assessed by complement fixation) is the only antibody as yet consistently found to be of higher titer in patients with acute rheumatic fever than in patients with acute glomerulonephritis in Trinidad, it was measured and the titers were related to serum levels of IgA. The titers of total antibody to MAP were greater than or equal to 40 in 58% of the rheumatic fever patients, 43% of the nephritis patients, and 8% of well school-children. However, its presence in rheumatic fever patients did not correlate directly with amounts of serum IgA present (r = 0.0507). Moreover, titers of total antibody to MAP related equally well to enzyme-linked immunosorbent assay indicated amounts of IgG antibody (r = 0.3939) and IgA antibody (r = 0.3054) to MAP in rheumatic fever patients but not in nephritis patients (r = 0.0301 for IgA antibody and 0.6909 for IgG antibody to MAP), whereas they related best to IgM antibody to MAP in the school-children (r = 0.4204).
特立尼达50例急性风湿热患者中，80%的患者血清免疫球蛋白A（IgA）显著升高，相比之下，63例急性肾小球肾炎患者中这一比例为20%，而两组中几乎所有患者的血清IgG均升高。由于在特立尼达，急性风湿热患者中总抗M相关蛋白（MAP）抗体（通过补体结合法评估）是目前唯一始终被发现滴度高于急性肾小球肾炎患者的抗体，因此对其进行了检测，并将滴度与血清IgA水平相关联。风湿热患者中58%的总抗MAP抗体滴度大于或等于40，肾炎患者中这一比例为43%，健康学童中为8%。然而，其在风湿热患者中的存在与血清中IgA的含量并无直接关联（r = 0.0507）。此外，在风湿热患者中，总抗MAP抗体滴度与酶联免疫吸附测定所示的抗MAP IgG抗体量（r = 0.3939）和IgA抗体量（r = 0.3054）的相关性同样良好，但在肾炎患者中并非如此（抗MAP IgA抗体r = 0.0301，抗MAP IgG抗体r = 0.6909），而在学童中，它们与抗MAP IgM抗体的相关性最佳（r = 0.4204）。
