Differences in hygienic habits and base-line secretory
immunoglobulin (Ig) A which might have contributed to the prevalence of skin
infections and/or absence of increased serum
IgA values were sought in patients with poststreptococcal acute
glomerulonephritis (
nephritis) in contrast to patients with
acute rheumatic fever in Trinidad by studying patients and their siblings after the patients had recovered from these diseases. The overall history of skin
infections was similar at this time in all groups, although they had been much more common in patients with
nephritis and their families at the time of acute illness. The recovered
nephritis patients bathed slightly less often than the other individuals, used a cream or lotion after bathing rather than
coconut oil, and tended to sweat less than the others, but none of these differences was statistically significant. Neither were significant differences demonstrated in amounts of
IgA and
IgG in serum and saliva of recovered
nephritis patients and their siblings compared to recovered
rheumatic fever patients and their siblings, while only small amounts of
IgA and
IgG were present in any sweat, and probably had been transuded rather than secreted. These studies suggest that the lower serum
IgA titers in patients with
nephritis compared to patients with
rheumatic fever in Trinidad do not reflect basic differences in serum
IgA or
secretory IgA as measured in saliva, and that
IgA is not secreted by the eccrine glands.