Dear Editor,

In the context of clinically suspected non-thyroidal illness(NTI) the advice to retest patients with raised levels of thyroid stimulating hormone(TSH)(1) may extend even to those in whom TSH levels are in the range 20-32.4 mIU/L(2). In one study, over a period averaging 88 days(Standard Error ie SE=34), seven such subjects, with mean baseline TSH of 32.4 mIU/L(SE=3.6), experienced a spontaneous fall in that parameter to levels averaging 12.3 mIU/L(SE=3.7)as a result of recovery from NTI. In two of those subjects, both of whom tested negative for antimicrosomal antibodies, TSH fell to 2.1 mIU/L, and 2.3 mIU/L, respectively. In the other five, all of whom were antibody positive, TSH levels fell to 9.9, 10.1, 11.5, 21.7, and 28.5 mIU/L,respectively. In order to check whether or not patients tested for TSH have significant but clinically unsuspected NTI it might even be advisable to test for the acute phase marker, C reactive protein(CRP). This was the strategy followed in one study so as to check if patients with suspected hypoferritinaemia might have spurious "normalisation" of their serum ferrtin levels attributable to an acute phase response. In that study 10.2% and 44% of patients in primary care and in secondary care, respectively, had elevated CRP levels(3). Where necessary, TSH levels also need to be interpreted in the context of advanced age, given the recent analysis of the age-specific distribution of TSH levels in 14,376 subjects who were not only disease-free, but also tested negative for thyroid antibodies. In that analysis the 95% confidence limits for TSH yielded the range 6.17-10.85 mIU/L in patients aged 80 or more(4). One interpretation of these findings was that the age- related shift in the reference range "could either facilitate or be a consequence of healthy aging"(4). This view resonated with the findings in a cohort of 599 subjects 37 of whom had overt hypothyroidism, the latter characterised by the association of subnormal levels of free thyroxine and TSH levels in the range 4.86-33.0 mIU/L. The enrollment age was 85, and the mean follow up was 3.7 years(standard deviation 1.4). Over that period, in spite of non-treatment, these overtly hypothyroid participants showed a significant trend towards the lowest mortality rates when compared with the rest of the cohort(Cox regression, P for trend=0.03). Furthermore, increasing baseline levels of TSH were not associated with an accelerated increase in phsical disability, cognitive decline, or depressive symptoms(5). Accordingly, in primary care best practice is to take account of NTI, using clinical criteria, and, possibly, CRP as well, and to take cognisance of advanced age.

Oscar M Jolobe
Retired Geriatrician

References

(1) Smellie WSA., Vanderpump MPJ., Fraser WD., Bowley R., Shaw N Best Practice in primary care pathology; review 11 Journal of Clinical Pathology 2008:61:410-18

(2)Spencer C ., Elgen A., Shen D et al Specificity of sensitive assays of thyrotropin(TSH) used to screen for thyroid disease in hoispitalised patients Clinical Chemistry 1987:33:1391-6

(3) O'Broin S., Kelleher B., Balfe A., mCMahon C Evaluation of serum transferrin receptor assays in a centralised iron screening service Clinical and Laboratory Haematology 2005:27:190-4

(4) Surks MI., Hollowell JG Age-specific distribution of serum thyrotropin and antithyroid antibodies in the U.S. population: Implications for the prevalence of subclinical hypothyroidism Journal of Clinical Endocrinology and Metabolism 2007:92:4575-82

(5) Gussekloo J., van Exel E., de Craen AJM et al Throid status, disability and cognitive function, and survival in old age Journal of the American Medical association 2004:292:2591-9

Dear Editor

I fully endorse the recommendations of Reddy and co-workers concerning management of potential Brucella isolates and those staff potentially exposed 1. The authors highlight that clinical information may not always suggest potential brucellosis, especially if time has elapsed since exposure, thus suspicion may not be raised. The authors then proceed to describe four blood culture isolates obtained from patients with travel histories to endemic regions. Although recovery of Brucella from blood cultures taken from patients with undulant fever is the typical text book scenario, readers should be aware that brucellae may result in focal lesions affecting nearly every organ 2. Unusual sources for isolation of brucellae are typified by the recent recovery of a Brucella-like organism from a breast implant 3.

The importance of non-blood samples for diagnosis of brucellosis must also be stressed. Where there is a suitable degree of clinical suspicion, bone marrow is the sample of choice for isolation. This is further substantiated by the recent findings of Mantur and co-workers who undertook a comparative study of Brucella recovery from various specimens. During these investigations, recovery was only achieved from 45.6% of blood cultures whereas 82.5% of bone marrow biopsies yielded growth 4.

Although the United Kingdom is officially Brucella-free, I would like to draw the attention of medical colleagues to recent human infections with marine mammal-associated brucellae. A paper by Sohn et al described two patients with neurological disease attributed to infection with strains of Brucella derived from marine mammals 5. Brucella was isolated following surgical intervention although only one patient was positive serologically. A further infection initially mistaken as B. suis, was reported from New Zealand 6. Previously, laboratory-acquired infection with a similar strain had been described 7. Serological and cultural evidence suggests that brucellosis is very widespread in a range of cetaceans, pinipeds around the coasts of the British Isles and elsewhere, and there is similar evidence that otters located inland are also infected 8.

Finally, regarding the application of PCR to identify Brucella in clinical material as used in case 4, this provides a useful diagnostic tool, negating the need to handle large quantities of this highly infectious microbe. Indeed, this has proven particularly valuable to confirm infection in patients, and household contacts with potential shared exposures 9. Molecular diagnostics have now evolved to offer equivalent discriminatory power to more traditional identification methods, however, cultivation and classical microbiological biotyping remain the gold standard, underscoring the need for precise recommendations for reduction of laboratory exposure, or appropriate management of exposed individuals, as outlined in the afore mentioned article.

Sally J Cutler

References:

1.Reddy S, Manuel R, Sheridan E, et al., Brucellosis in United Kingdom - a risk to laboratory workers? Recommendations for prevention and management of laboratory exposure. Journal of Clinical Pathology, 2008:jcp.2007.053108.

2.Al Dahouk S, Nockler K, Hensel A, et al., Human brucellosis in a nonendemic country: a report from Germany, 2002 and 2003. Eur J Clin Microbiol Infect Dis, 2005;24:450-6.

3.De BK, Stauffer L, Koylass MS, et al., Novel Brucella Strain (BO1) Associated with a Prosthetic Breast Implant Infection. Journal of Clinical Microbiolology 2008;46:43-49.

4.Mantur BG, Mulimani MS, Bidari LH, et al., Bacteremia is as unpredictable as clinical manifestations in human brucellosis. Int J Infect Dis, 2008;12:303-7.

5.Sohn AH, Probert WS, Glaser CA, et al., Human neurobrucellosis with intracerebral granuloma caused by a marine mammal Brucella spp. Emerging Infectious Diseases, 2003;9:485-488.

6.McDonald WL, Jamaludin R, Mackereth G, et al., Characterization of a Brucella sp. Strain as a Marine-Mammal Type despite Isolation from a Patient with Spinal Osteomyelitis in New Zealand. Journal of Clinical Microbiolology, 2006;44:4363-4370.

7.Brew SD, Perrett LL, Stack JA, et al., Human exposure to Brucella recovered from a sea mammal. Veterinary Record, 1999;144:483.

8.Foster G, MacMillan AP, Godfroid J, et al., A review of Brucella sp. infection of sea mammals with particular emphasis on isolates from Scotland. Vet Microbiol, 2002;90:563-80.

9.Mendoza-Nunez M, Mulder M, Franco MP, et al., Brucellosis in Household Members of Brucella Patients Residing in a Large Urban Setting in Peru. Am J Trop Med Hyg, 2008;78:595-598.

We thank the reader for the careful and critical evaluation of our publication “Value of multicolor Fluorescence in situ Hybridization (UroVysionTM) in the differential diagnosis of flat urothelial lesions” published by Stephan Schwarz, Michael Rechenmacher, Tomas Filbeck, Ruth Knuechel, Hagen Blaszyk, Arndt Hartmann and Gero Brockhoff. The reader realized some inconsistency in the Material and Methods section of our paper regarding HER2 immunohistochemistry (IH). In our lab for some purposes a manual IH procedure is performed, for others we execute an automated one. In fact for the study published by Schwarz et al. we used a combination of both: section preparation was done manually and the subsequent staining procedure was performed on the NexES immunostainer (Ventana Medical Systems, Tucson, Arizona, USA). However, we agree with the reader that we produced some inconsistency and incorrectnesses in the Material & Methods. Hence we would like to provide this amended description of immunohistochemical HER2 staining and interpretation as follows:

“HER2 immunostaining was done on 2 mm sections using a HER2 antibody (CB11 CB11-Pathway, prediluted, FDA approved, Ventana Medical Systems, Tucson, Arizona, USA). Before staining, the tissue slides were deparaffinised and rehydrated at room temperature. For antigen retrieval the sections were immersed in 10 mmol/l citrate buffer and microwaved for 30 min using 300 Watt (no pressure cooker was used). Subsequently the sections were cooled by rinsing water for a couple of minutes. Then an automated staining protocol on the NexES immunostainer (Ventana Medical Systems, Tucson, Arizona, USA) was performed featuring some slight modifications with respect to the recommendation given by Ventana (http://www.ventanamed.com/msds/files/14160USb2.pdf). The protocol described here numerously proved to work reliably on the NexES immunostainer. After a 30-minute incubation at 37°C with the primary antibody, sections were incubated for another 10 minutes at 37°C with a secondary biotinylated antibody and then with avidin-peroxidase for another 10 minutes; 3',3-diaminobenzidine was used as the chromogen. All products needed for these steps are included in the DAB detection kit provided by the manufacturer (Ventana Medical Systems, Tucson, Arizona, USA). Slides were haematoxylin counterstained, dehydrated, and mounted. A multiblock control consisting of four cell lines representing different staining intensities ranging from 0 to 3+ (MDA-MB-231: Score 0, MDA-MB-175: Score 1+, MDA-MB-453: Score 2+, and SK-BR-3: Score 3+) served as controls for all specimens.

Again we would like to thank for the careful reading of our manuscript and for coming up with the letter to the editor. This procedure assures appropriate publication quality of JCP.

Gero Brockhoff (correspondence author)

Dear Editor,

I was very interested to read your article which was based on work we carried out a number of years ago. We feel it is important that the safety aspects of handling fish under the conditions described in the work are widely publicised.

If readers would like a more detailed account of the work carried out they will find it in: James, S.J., James, C , Jones, S & Swain, M.J. 2000 Toxin production in fishing vessels Institute of Chemical Engineering Food & Drink 2000 Processing solutions for innovative products, Institution of Chemical Engineers, UK, ISBN 0 85295 438 7 121-124.

We would also be very interested in becoming involved in any further work that would ensure that further occurrences of the problem and the subsequent loss of life and suffering are eliminated.

Stephen J James

(Director FRPERC)

University of Bristol