It has been reported that during pregnancy, levels of thyroid peroxidase and thyroglobulin antibodies decrease. After giving birth, Tregs rapidly decrease and immune responses are re-established. It may lead to the occurrence or aggravation of the autoimmune thyroid disease. In up to 50% of females with thyroid peroxidase antibodies in the early pregnancy, thyroid autoimmunity in the postpartum period exacerbates in the form of postpartum thyroiditis. Higher secretion of IFN-γ and IL-4, and lower plasma cortisol concentration during pregnancy has been reported in females with postpartum thyroiditis than in healthy females. It indicates that weaker immunosuppression during pregnancy could contribute to the postpartum thyroid dysfunction. Fetal microchimerism
Several years after the delivery, the chimeric male cells can be detected in the maternal peripheral blood, thyroid, lung, skin, or lymph nodes. The fetal immune cells in the maternal thyroid gland may become activated and act as a trigger that may initiate or exaggerate the autoimmune thyroid disease. In Hashimotos disease patients, fetal microchimeric cells were detected in thyroid in significantly higher numbers than in healthy females. See also
Hashimotos encephalopathy
Myxedematous psychosis
Hashitoxicosis


== References ==
It has strong antimicrobial activity because of its high affinity for penicillin binding protein 2X, which responsible for cephalosporin resistance when mutated. Cefditoren pivoxil high intrinsic activity against Streptococcus pneumoniae, including penicillin-resistant strains. Cefditoren holds a balanced antimicrobial spectrum that includes the three major pathogens of community-acquired lower-respiratory tract infections: Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. Aerobic Gram-positive microorganisms: Staphylococcus aureus (methicillin-susceptible strains, including β-lactamase-producing strains), Streptococcus pneumoniae, Streptococcus pyogenes
Aerobic Gram-negative microorganisms: Haemophilus influenzae (including β-lactamase-producing strains), Haemophilus parainfluenzae (including β-lactamase-producing strains), Moraxella catarrhalis (including β-lactamase-producing strains. Pharmacokinetics
Absorption
Oral bioavailability: following oral administration, cefditoren pivoxil is absorbed from the gastrointestinal tract and hydrolyzed to cefditoren by esterases. Maximal plasma concentrations of cefditoren under fasting conditions average 1.8 ± 0.6 µg/mL following 200 mg dose and occur 1.5 to 3 hours following dosing. Cefditoren does not accumulate in plasma following twice daily administration to subjects with normal renal function. Under
fasting conditions, the estimated absolute bioavailability of cefditoren pivoxil is approximately 14%. Distribution
Binding of cefditoren to plasma proteins averages 88%, and the mean volume of distribution of cefditoren at steady state is 9.3L. Cefditoren has been shown to penetrate into bronchial mucosa, epithelial lining fluid, skin blister fluid and tonsillar tissue and clinically relevant concentrations against common pathogens are achieved in these tissues for at least 4 hours. Metabolism and Excretion
Cefditoren is predominantly eliminated by the kidneys as unchanged drug and has a renal clearance of 4.1–5.6 L/h after multiple doses; its elimination half-life is 1.5 hours.