What is autoimmune thyroid disease

Autoimmune thyroid disease is a disease caused by autoimmune disorder. The incidence rate of female patients is higher than that of male patients, and most of the patients are middle-aged and elderly people. The main symptom of the disease is proteinuria. Some tests and clinical diagnosis are needed to determine whether you have autoimmune thyroid disease. Let’s learn more about what autoimmune thyroid disease is.

The prevalence of autoimmune thyroid disease in women is significantly higher than that in men, and most people believe that estrogen plays a very important role. The positive rate of thyroid peroxidase antibody (TPOAb) in women under 70 years old is significantly higher than that in men, and the levels of serum IgG and IgM in women are higher. However, some studies have also obtained completely different results. For example, the incidence of thyroid autoantibodies and some AITD such as Graves' disease (GD) in women is significantly reduced after they use estrogen replacement therapy (HRT) or contraceptives.

pathology

Autoimmune thyroid disease (AITD) is a thyroid disease caused by autoimmune disorders. Autoantibodies against thyroid antigens, including thyroglobulin antibodies and thyroid microsomal antibodies, can be detected in the blood of patients. Patients may have mild proteinuria and a few may even develop nephrotic syndrome. A literature report on 85 AITD patients found that proteinuria was as high as 40%. Studies have shown that the occurrence of this type of proteinuria may be related to autoimmunity. Many reports on renal biopsy of AITD combined with proteinuria have shown thyroid antigen deposition in renal tissue. It is believed that thyroid antigen-antibody complexes may be deposited in renal tissue through blood circulation, leading to immune complex nephritis.

Foreign scholars believe that the pathogenesis of AITD membranous nephropathy may be the deposition of thyroid globulin and thyroid microsomal antigens outside the glomerular basement membrane, leading to the formation of in situ immune complexes, and in some cases, circulating immune complex mechanisms may be involved.

symptom

There are mainly two symptoms: clinical manifestations of AITD and proteinuria. Proteinuria is mostly mild, but sometimes it presents as nephrotic syndrome. AITD and proteinuria occur simultaneously or successively. Sometimes AITD appears first and sometimes proteinuria appears first. The interval between the two can even be as long as more than 10 years.

Clinical diagnosis

This disease should be considered when AITD is combined with proteinuria, but attention should be paid to distinguishing whether the two are two independent diseases. The confirmation that proteinuria is caused by AITD depends on the discovery of thyroid antigen deposition in renal tissue during renal biopsy. Since AITD and proteinuria do not necessarily occur at the same time, when diagnosing AITD, attention should be paid to checking for the presence of proteinuria. Conversely, when diagnosing various immune complex nephritis, care should be taken to exclude AITD.

Differential diagnosis: AITD should be differentiated from various immune complex nephritis.

examine

Laboratory examination: There may be laboratory manifestations of nephrotic syndrome. Proteinuria and AITD may occur simultaneously or sequentially, occasionally accompanied by microscopic hematuria, but without hypertension or renal impairment.

Other auxiliary examinations:

Renal biopsy shows that the most common pathological type of AITD-related nephrotic syndrome is membranous nephropathy, which may also be accompanied by mesangial proliferative nephritis and focal glomerulosclerosis. Specific changes are the presence of thyroid antigen deposition in renal tissue biopsy.