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Recently, the case of a 9 year old boy presenting with cardiac failure was presented in the Annals of the Rheumatic Diseases.1 It was reported as a case of Takayasu's arteritis in a child with a CD4+ lymphopenia and dysgammaglobulinaemia. I have a number of problems with this case:
As presented in table 1 in the letter, this 9 year old child has a normal CD4 cell count with a low total lymphocyte count. Is the table wrong or did this child actually have a normal CD4 lymphocyte count?
The dysgammaglobulinaemia actually consisted of a modest rise in the IgG level, with a normal IgA, and a borderline low IgM level of rather questionable relevance in such a sick young child.
The evidence for Takayasu's arteritis is rather circumstantial, based entirely on magnetic resonance imaging with some suggestive clinical findings in a very sick child presenting with cardiac failure. Surely in such a case, especially when the end result was death soon after initiating immunosuppressive treatment, attempts should have been made to secure a pathological diagnosis, either before or after the final outcome. No mention of this was made in the report.
I remain unconvinced that this was a case of Takayasu's arteritis and there is no evidence presented to suggest that this child did have a CD4+ lymphopenia,
We thank Dr Smith for his comments and would like to reply to the points he made.
Firstly, we agree that the absolute CD4 number was not correct in the table. It was incorrectly converted in the editorial process from the value/mm3 and should have been 0.2×109/l rather than 2×109/l. We regret that this point was overlooked on the proofs.
Secondly, a polyclonal hypergammaglobulinaemia is present in one third of cases with Takayasu arteritis. The serum immunoglobulin levels of our patient are consistent with Takayasu arteritis. Dr Smith mentioned a modest rise in the IgG level, with a normal IgA level, but our patient had high levels of both IgG and IgA.
Finally, the classification criteria for Takayasu arteritis according to the American College of Rheumatology (ACR) are: (a) age at disease onset in years <40; (b) claudication of the arms and legs; (c) decreased brachial artery pulse; (d) blood pressure difference >10 mm Hg, (e) bruit over subclavian arteries or aorta; (f) arteriogram abnormality. Our patients had all six of these criteria. In addition to the ACR criteria, our patient had one obligatory, one major, and five minor criteria for the clinical diagnosis of Takayasu's disease according to Ishikawa's criteria.1 These criteria comprise one obligatory criterion, two major criteria, and nine minor criteria. In addition to the obligatory criterion, one major and two or more minor criteria suggest a high probability of the presence of Takayasu's disease.
These data prove that there is no reason to doubt the diagnosis of this case as Takayasu arteritis. Additionally, the patient had a low CD4 count associated with hypergammaglobulinaemia.