Some of these activated B-cells mature directly into plasma cells and produce IgM antibodies.

其中一些被激活的B细胞直接成熟分化为浆细胞并产生IgM抗体。

These centroblasts have a rearrangement of their immunoglobulin genes, and some of them undergo a class switch where they change from producing IgM antibodies to producing IgG or IgA antibodies.

这部分中心母细胞的免疫球蛋白基因发生了重排，其中的一些会经历Ig类别转换，从产生IgM变成产生IgG或IgA。

Immunoassays may detect IgG antibodies, the most abundant class, and IgM antibodies, the type that's first produced in response to a new infection.

免疫测定可以检测 IgG 抗体（最丰富的一类）和 IgM 抗体（应对新感染而首先产生的抗体）。

The presence of IgM antibodies suggests a recent infection, but since it can take the body over a week to produce a detectable amount, they're unreliable in diagnosing current infections.

IgM 抗体的存在表明近期感染，但由于身体需要一周以上的时间才能产生可​​检测的量，因此它们在诊断当前感染方面并不可靠。