Nearly all CVID patients possess a concomitant reduced amount of IgA and or IgM furthermore to reduced IgG levels . B) and will need to have supportive lab proof (either category C or D criteria). Table 2 New diagnostic criteria for CVID A. Must meet all major criteriaimmune system failure (ISF) (1 or more criteria)etc hr / D. Presence of any one of relatively specific histological markers of CVID (Not required for diagnosis but presence increases diagnostic certainty) hr / ?? Lymphoid interstitial pneumonitis hr / ? Granulomatous disorder hr / ? Nodular regenerative hyperplasia TBK1/IKKε-IN-5 of the liver hr / ? Nodular lymphoid hyperplasia of the gut hr / ? Absence of plasma cells on gut biopsy Open in a separate window Meeting criteria in categories ABC or ABD indicates probable CVID. Patients meeting criteria ABC and ABD should be treated with IVIG/scIG. Patients meeting criteria A alone, AB or AC or AD but not B, are termed possible CVID. Some of these patients may need to be treated with TBK1/IKKε-IN-5 IVIG/scIG. Patients with levels of IgG 5 g/l, not meeting any other criteria are TBK1/IKKε-IN-5 termed hypogammaglobulinemia of uncertain significance (HGUS). A detailed review of these criteria have been recently published . This patient did not meet category C or D criteria. Analysis of his serum immunoglobulin profile of reduced IgG with preserved IgM was compatible with protein-losing enteropathy induced by NSAID abuse. His IgA level returned to the normal range (0.8 g/l, nr 0.8) just before he was lost to follow up. The majority of CVID patients have a concomitant reduction of IgA and or IgM in addition to reduced IgG levels . Review of his blood transfusion records showed the presence of isohemagglutinins, indicating preserved antibody responses to carbohydrates. The presence of normal numbers of switched memory B cell subsets, although only undertaken on one occasion  makes it is unlikely this patient had CVID. We did not measure his IgG3 level and we did not undertake studies of susceptibility genes for CVID . He does not have category D criteria, which are the presence of characteristic histological TBK1/IKKε-IN-5 markers of CVID, such as granulomatous disease . Retrospective review of his intestinal biopsies confirmed the presence of plasma cells, again making LSM6 antibody CVID very unlikely . He therefore does not meet the proposed new criteria for CVID (Table?2) . Application of these criteria will be helpful in distinguishing CVID from cases of secondary hypogammaglobulinemia. Patients with factitious disorder are notoriously difficult to treat . When their deception is uncovered, it may provoke anger and patients frequently discharge themselves from medical care. They may continue to seek treatment at other medical institutions (peregrination). There is usually lack of insight and these patients rarely engage in on-going psychotherapy. Long-term follow up studies of large cohorts of such patients are absent from the medical and psychiatric literature . Like many others, our patient had a link to the medical profession . This is the first factitious presentation of a well-defined primary immune deficiency disorder, which we have termed hypogammaglobulinemia factitia. Given the uncanny resemblance to refractory CVID, factitious disorder was not suspected for several months. It is unclear if this patient intended to simulate CVID. His behaviour does not suggest drug addiction. Although ibuprofen products in New Zealand often contain codeine, it is unlikely that the non-disclosure of the NSAIDs was due to substance abuse as there was no drug seeking behaviour or requests for more potent opiates. If codeine abuse was main issue, there would have been no need for the patient to use a combination drug. Furthermore there was unquestioning willingness C even eagerness – to undergo more invasive and dangerous treatments as has been described in factitious disorder . The family also reported that the patient avidly discussed his ongoing medical care.