Haematological manifestations in patients with severe acute respiratory syndrome: retrospective analysis

TO THE EDITOR: Currently there is no consensus and or FDA approved
treatment for SARS. In June 21 issue, Dr. Raymond S M Wong reported that
for all SARS patients received broad spectrum antibiotics and a
combination of ribavirin and prednisolone 0.5 mg/kg/day as empirical
treatment. Intravenous methylprednisolone at high dosage was used in
patients with respiratory distress or progressive consolidations on their
chest radiograph. (1) But the treatment of SARS patients with ribavarin
and corticosteroids remains controversial.(2) The underlying idea of
administering corticosteroids is the possible suppression of the cytokine
storm that may worsen lung injury caused by the infectious agent. (2) And
the sceptical idea is use of corticosteroids with possibly ineffective
antiviral agents in patients with viral-induced pneumonitis can be
hazardous.(2)

We believe, if one decide to administer corticosteroids, one should
be aware of complications such as superinfections with Aspergillus,(3)
which is a known complication in any patient receiving corticosteroids
(4). Therefore we suggest to monitor SARS patients receiving
corticosteroids for aspergillosis. Since cultures for Aspergillus are
usually very slow (it may take up to six days) and characterized by low
sensitivity, we would advice to introduce a real time polymerase chain
reaction (PCR) assay for the detection of 18SrRNA Aspergillus-specific
sequences with bronchoalveolar lavage (BAL) fluid specimen, especially
when used in association with galactomannan (GM) antigen detection by
Enzyme-Linked Immunosorbent Assay (ELISA) as is recently described by
Sanguinetti et al (5). This promising method for diagnosis of
aspergillosis is a highly sensitive, fast and specific noninvasive
procedure, it is certainly less traumatic than lung biopsy. (5, 4)
However, we also feel that clinical presentation, radiology and direct
microbiological examination from culture for bacteria and fungi remains
essential. These assays may lead to early detection and possible to a very
early treatment of Aspergillus, which is mandatory in any patient
suspected of aspergillosis. It could be argued that if any of the four
tests mentioned is positive for Aspergillus treatment should be
instituted.
In conclusion, when SARS patients are given costicosteroids, patients
should be continuously monitored for possible superinfections. Cultures
together with real time PCR and galactomannan (GM) or other antigen,
antibody ELISA are important diagnostic features in order to make early
treatment of asperagillus possible.

References

1. Wong RS, Wu A, To KF, Lee N, Lam CW, Wong CK, Chan PK, Ng MH, Yu
LM, Hui DS, Tam JS, Cheng G, Sung JJ. Haematological manifestations in
patients with severe acute respiratory syndrome: retrospective analysis.
BMJ. 2003;326(7403):1358-62.

2. Oba, Y. Lee N., Sung JJ. The Use of Corticosteroids in SARS.
Correspondence and the authors reply, N Engl J Med 2003;348(20):2034-2035.

3. Wang H, Ding Y, Li X, et al. Fatal aspergillosis in a patient
with SARS who was treated with corticosteroids. N Engl J Med
2003;349(5):507-508.

4. Muller FM, Trusen A, Weig M. Clinical manifestations and diagnosis
of invasive aspergillosis in immunocompromised children.
Eur J Pediatr. 2002;161(11):563-74.

5. Sanguinetti M, Posteraro B, Pagano L, Pagliari G, Fianchi L, Mele
L, La Sorda M, Franco A, Fadda G. Comparison of real-time PCR,
conventional PCR, and galactomannan antigen detection by enzyme-linked
immunosorbent assay using bronchoalveolar lavage fluid samples from
hematology patients for diagnosis of invasive pulmonary aspergillosis.
J Clin Microbiol. 2003 Aug;41(8):3922-5.

Competing interests:  
None declared