A 37-year-old man presented to the emergency department of a level III hospital in the city of Cali (Colombia) complaining of respiratory distress, fever and cough with greenish expectoration of approximately one week duration, with worsening dyspnea in the past 48 hours until being unable of performing any minimal effort. At admission, he presented hypotension (78/36), tachycardia (126 beats/min), and tachypnea (38 breaths/min), with saturation of 76% O2 (O2 atmosphere); lung auscultation revealed multiple over-aggregate and overall decreased breath sounds. The patient reported having immunodeficiency antibody. Few minutes after admission, he presented respiratory failure requiring intubation and vasoactive support with mechanical ventilation. On suspicion of septic shock, antibiotic coverage was initiated with vancomycin and cefepime, after taking blood cultures.
The patient is native to, and came from Cali (Valle province, in Colombia). As relevant background, he refers pneumonia, sinusitis and recurrent otitis since he was aged 18 yrs, with countless episodes (6 to 10 per year) requiring long courses of oral or intravenous antibiotics and multiple hospitalizations. Since 2002 cylindrical and cystic bronchiectasis had been documented in all four quadrants (Fig. 1A), equally documented in the cross sections at the level of the aortic arch and the left ventricle (Fig. 1B y1C).
Studies for cystic fibrosis and autoimmunity were performed with negative results. In 2006, he received six months of supervised shortened treatment for pulmonary tuberculosis, diagnosed by positive sputum culture at 12 weeks (serial smear negative), with microbiological cure. He had consulted countless times different specialties and subspecialties of internal medicine, and despite having documented very low titers of total serum immunoglobulins (at least 5 yrs prior to this hospitalization), for unclear reasons he did not receive any replacement therapy. Tests for HIV antibodies were performed for over 7 times with negative results.
Paraclinical income tests showed leukocytosis (17,820/mm3) at the expense of neutrophilia (79%), major bandemia (11%) without anemia (Hb 13.8 g/dL), normal platelets (281,000/mm3), and elevated acute phase reactants (94 CRP mg/L). Kidney function was normal, with no proteinuria; however, the patient had a markedly hypoproteinemia at the expense of globulins (total protein 4.8 g/dL albumin 3.6 g/dL, globulins 1.2 g/dL). Quantification of total serum immunoglobulins by nephelometry showed severe hypogammaglobulinemia (Total IgG <140 mg/dL, Total IgA, 2.9 mg/dL; Total IgM <5 mg/dL) with an electrophoresis protein value compatible with agammaglobulinemia. The same day of admission, intravenous human immunoglobulin (IVIG) was initiated at a rate of 800 mg/kg. Mechanical ventilation was required for 5 days, with no pathogen documented in the cultures. The patient received outpatient oral antibiotics, for which he completed 14 days of empirical antibiotic therapy. 
The patient was examined by the Immunology service prior to the start of IGIV, it was found that both the responses to vaccine antigens and infectious pathogens were absent; anti-core antibodies (Anti core-HBV) and antibodies to Hepatitis B surface antigen were determined (Anti-HBsAg), as well as fourth generation EIA for HIV, total antibodies against hepatitis C virus (HCV), IgM and IgG antibodies against cytomegalovirus (CMV), herpes simplex IgG for 1-2 virus (HSV), and IgG antibodies against tetanus and rubella. The findings demonstrated not only the (specific) quantitative deficiency but also a defective functional humoral immune response. Evaluation of lymphocyte subpopulations in peripheral blood showed an absolute B lymphocyte count of 420 normal cells/microL (100-500) (Fig. 2C), accompanied by inversion of the lymphocyte T CD4+/CD8+ ratio, at the expense of a decrease in CD4+ T lymphocytes to 190 cells /L (300-1,400) (Fig. 2B).
At present, the patient receives IGIV 10% at a dose of 800 mg/kg every 4 weeks, he receives prophylaxis with TMP/SX 160/800 mg every other day, he completed a cycle of 22 sessions of pulmonary rehabilitation, and he is managed jointly by the Immunology, Pneumology and Internal Medicine services. His evolution has been satisfactory during the last year after the start of replacement therapy with IVIG, the patient had only one episode of pneumonia that required a short course of levofloxacin with excellent response; however, his lung capacity is very limited, which requires continuous oxygen therapy. The clinical picture of this patient, the serologic findings, the low titers of serum immunoglobulins, and the presence of B lymphocytes (CD19+/CD20+) in peripheral blood determine a diagnosis of Common Variable Immunodeficiency (CVID).