Primary Immune Deficiencies (PID) are hereditary diseases mediated by the defects of genes controlling immune response. Clinical manifestations and adequate laboratory tests distinguish pathologies on lymphatic level as well as non-lymphatic mechanisms of Ag destruction and removing.
• Summary frequency of PID is 1 per 10,000-100,000 alive new-born babies. Selective IgA deficiency is significantly more frequent: 1 per 500- 1500 subjects of the same population. Most PIDs are manifested in early childhood. If a baby is afflicted with infectious diseases some 10 times per year, PID may be suspected. In children PID infections may acquire a long-term character manifesting in developmental lagging, recurrent sinusitis, otitis, pneumonia, diarrhea, malabsorption, and candidiasis.
• Infectious syndrome. In PID clinical manifestation the so-called clinical syndrome is major. It means an increased susceptibility (hypersuscepti-bility) to infections, extremely severe development and recurrent course; atypical infectious agents (opportunistic pathogens are frequent). Infectious syndrome is characteristic but not pathognomonic for true immune deficiencies. In other words, always accompanying immune deficiencies, the syndrome may as well occur without them.
• Physical examination. Lymph nodes or tonsils may be impalpable.
• Laboratory tests. If PID is suspected by clinical manifestation the following laboratory tests are to be performed: ❖ for HIV-infection; ❖ Haemo-gram; ❖ blood serum IgG, IgA, and IgM; ❖ DTH in skin samples for the following Ag: tetanic, diphtheritic, streptococcal Ag, tuberculin, Ag of Proteus mirabilis, Trichophyton mentagrophytes, Candida albicans; ❖ T-and B-lymphocytic subpopulations count by specific indications; phagocytosis state (the most simple and informative test is tetrazolium blue reduction); ❖ Complement components (beginning with C3 and C4) analysis; ❖ Molecular genetic studies (if genetic therapy is perspective).