Common variable immunodeficiency (CVID) is a highly heterogeneous disease with an unpredictable pattern. CVID appears to have an immunologic and clinical phenotype similar to some hereditary humoral immunodeficiencies, including X-linked lymphoproliferative disease (XLP). The differential diagnosis of CVID and XLP is clinically of importance, because the two diseases have markedly different prognoses and treatment. The recent identification of the XLP gene, known as SH2D1A, has permitted a definitive diagnosis of XLP. In this report, we describe a male patient with XLP who initially received a diagnosis of CVID and developed a fatal course. Using genetic analysis, we confirmed that the patient harbored the SH2D1A gene mutation. The results support the notion that the possibility of a SH2D1A gene mutation should be considered in hypogammaglobulinemic male patients before a diagnosis of CVID is made.

Epidemiological studies have shown wide geographical and racial variation in the prevalence and patterns of immunodeficiency disorders. To determine the frequency of primary immunodeficiencies (PID) in Iran, the Iranian Primary Immunodeficiency Registry (IPIDR) was organized in 1999. We extracted the patient's data, by using a uniform questionnaire from their hospital records. The diagnosis of patients was based on WHO criteria. By now, 440 patients with PID, who were observed during a period of 20 years, have been registered in our registry. Among these patients, the following frequencies were found: predominantly antibody deficiency in 45.9% of patients (n = 202), phagocytic disorders in 29.09% (n = 128), T-cell disorders in 24.31% (n = 107), and complement deficiencies in 0.68% (n = 3). Common variable immunodeficiency was the most frequent disorder (n = 98), followed by chronic granulomatous disease (n = 86), ataxia telangiectasia (n = 48), x-linked agammaglobulinemia (n = 45), selective IgA deficiency (n = 42), combined immunodeficiency (n = 15), and severe combined immunodeficiency (n = 14). This study revealed that antibody deficiencies is the most frequently diagnosed primary immunodeficiency disorder in our patients, which is similar to that observed in other registries. A comparative study shows some differences between our results and other registries.

In this retrospective study, the feasibility and implementation of a clinical guideline was evaluated in 130 consecutive patients with chronic urticaria. We analysed how often a questionnaire was used, how often routine laboratory tests were performed and on what information (history-taking, detailed questionnaire, laboratory or provocation tests) the diagnosis was made. In this validation sample, the number of identified diagnoses was compared with the number of identified diagnoses of a prospective study previously performed in the same hospital. A cause was identified in 58 patients (45%): 43 of these had physical urticaria and 15 had chronic urticaria. In 50 of the 58 patients (86%) the cause was identified by history-taking and in 8 patients by additional use of the questionnaire. In 38 patients the questionnaire was not in the patient's file. In 89 of 130 patients (68%), laboratory tests were performed without a reason suggested by the patients' history. This did not reveal a cause in any patient. In general, the diagnostic guideline was followed reasonably well. In identifying a cause of urticaria, careful history-taking was important; routine laboratory tests were not helpful. A detailed questionnaire is presented in an appendix.