制作人： 董天一 付金秋 李玉叶 齐霞风 王 哲 相晓娟 赵 静 朱 莎

CASE STUDY A 29-year-old man had a history of cough, sputum and hemoptysis for 22 years. The disease outbreaks 3 to 5 times with a duration of one month.. He had attack of viral myocarditis, pleuritis, sinusitis and bacterial pneumonia. When he was admitted into hospital, he was in fever( T=39-41 ℃ ), cough, blood-tinged sputum with night sweat for 17 days.

CASE STUDY T=38.7 ℃ Heart Rate=96times/min Blood Pressure=136/75mmHg Quantitation of serum immunoglobulins showed: IgG<1.89g/L(NR:8-15g/L) IgM<0.225g/L(NR:0.83~3.0g/L) IgA<0.183g/L(NR:0.5~2.5g/L) B cell count is normal.

Diagnosis Lower respiratory tract infection Common variable immunodeficiency (CVID)

*QUESTIONS**QUESTIONS* What is CVID? Why does the patient suffer from frequent infections? How dose it treated and what about the prognosis?

CVID Common variable immunodeficiency is a group of unclarified immune diseases with low blood level of gamma immunoglobulin as its character.

Mechanism 1.Genetic factor 1.Genetic factor 2.B cell abnormality 2.B cell abnormality 3.T cell abnormality 3.T cell abnormality 4.Autoimmunity

YES!! Patients with CVID has something wrong with Ig production ↓ The patient is lack of immunoglobulin

Let ’ s come to the function of Ig!

The function of Ab 1) Neutralization 2) Activate complement system 3) Opsonization – macrophage 4) ADCC — NK

ADCC

IgG 1.Highest concentration in serum(75% of total Ig) 2.Functions of IgG: against bacteria and virus, neutralize toxin some belong to the auto-antibodies: eg. long active thyroid stimulator (LATS) combine with the Fc receptor (FcγR)

Now, we know the antibody plays an important role in anti-infections of our bodies oh oh! If we are lack of antibody, our bodies will be susceptive to infections!! Such as in CVID!!

Treatment Immunoglobulin and frequent use of antibiotic are usually required. Additional immunoglobulin should be given during an acute illness. The gamma-immunoglobulin is the first choice ( g/Kg every month) to keep the level of serum IgG at 3- 4g/L. If plasma is used, the dosage is 100mg/Kg every month.

Prognosis Even though the patients may live a long life(70 )with proper treatment mentioned above, the prognosis can not be considered satisfied enough. Because many patients may induced into chronic infections, especially the chronic respiratory infections; part of the patients complicated with autoimmunity disease and cancer.

There is still a long journey before we cure the CVID! Let’s start,NOW!!

1 Genetic Factor Even though most cases are scattered, some cases have family history, especially occur along with selective IgA abscent disease. From the truth above, we can induce that both diseases due to some gene mutation. MHC Ⅲ complement gene mutation is the most suspicious.

B cell abnormality (1)Abnormal B cell production (2)Disorder of B cell differentiation (3)Disfuntion of B cell (4)Inhibitory factor of B cells

T cell abnormality (1)Disfunction of Th 2 cell (1)Disfunction of Th 2 cell (2)Disfunction of Treg cell (2)Disfunction of Treg cell

Normal Th 2 help B cell activation

T reg cell T reg cell is a kind of CD4+T cell with CD25 expressed on it and it can produce a kind of protein called foxp3. T reg cell plays an important role in regulation of immune response. It suppresses B cell response by secreting cytokines such as TGF-beta and IL-10.

4 Autoimmunity In some cases, serological test showed positive anti-B cell antibody or anti-T cell antibody, the finding indicated the present of autoimmunity. Serum dialysis is an efficient way to eliminate anti-B cell or anti-T cell antibodies, thus the B cell count rise dramatically in the patient ’ s serum.