One hundred fifty war veterans with ankylosing spondylitis were entered into a prospective study in 1947. In 1957, 142 were traced, and they have been reviewed periodically. Eighty‐one of these patients were still alive in 1980. Information was obtained from 67 (83%) of the survivors and 51 were reexamined. This report is based on the clinical findings in these 51 patients, who have a mean disease duration of 38 years. Forty‐seven (92%) were functioning well. The disease in 21 (41%) had progressed to cause severe spinal restriction. Of those, 12 had peripheral joint involvement early in their course and 9 had iritis. Seventy‐four percent of the patients who had mild spinal restriction after 10 years did not progress to having more severe restriction. Eighty‐one percent of the patients who had severe spinal restriction in 1980 were severely restricted within the first 10 years. Hips that were normal after 10 years of disease did not become diseased subsequently. This study suggests that a predictable pattern of ankylosing spondylitis emerges within the first 10 years of the disease.

HLA-B27 appears to play a direct role in the pathogenesis of ankylosing spondylitis and almost all patients with this disease have HLA-B27. Therefore, a diagnosis of ankylosing spondylitis can virtually be excluded in the absence of HLA-B27. Many techniques have been used for HLA-B*27 typing. Of these, molecular methods are the most sensitive and specific but require extracted DNA as the testing material. A technique where HLA-B*27 is amplified directly from whole blood using sequence specific primers has been developed. This technique uses small sample volumes, is not restricted by choice of anticoagulant or sample age up to at least six weeks, and can be applied to other clinical polymerase chain reaction based procedures. (J Clin Pathol: Mol Pathol 1999;52:300-301) Keywords: ankylosing spondylitis; HLA-B*27; whole blood; sequence specific primers Testing for HLA-B27 is of clinical importance for the diagnosis of ankylosing spondylitis. Excluding HLA-B27 virtually excludes ankylosing spondylitis.1 Serological techniques such as microcytotoxicity and flow cytometry for testing for HLA-B27 require viable cells that adequately express HLA-B27 and may give false negative results if HLA-B27 is downregulated or "masked".2 3 Flow cytometry is rapid and relatively inexpensive, but has been reported to lack specificity, especially in the presence of antigens that crossreact with HLA-B27, such as HLA-B7. 4 Molecular techniques are sensitive and specific. However, DNA extraction makes the procedure cumbersome, time consuming, and therefore unattractive to routine clinical laboratories.We have developed a procedure for the detection of HLA-B*27 after amplification with sequence specific primers directly on whole blood (WBSSP).Previous attempts to amplify directly from whole blood have been inconsistent, probably because of the physical entrapment of DNA by blood proteins that are denatured as a result of the high temperatures encountered during the polymerase chain reaction (PCR). However, incorporating formamide into the PCR mix reduces the melting temperature of DNA and allows the PCR cycles to be performed at much lower temperatures, resulting in successful amplification. 5 Materials and methods TEST SAMPLESOne hundred and forty two samples of blood collected into tubes containing acid citrate dextrose (Becton Dickinson, New Jersey, USA) were used in the initial WBSSP evaluation. All samples were selected randomly from routine HLA typing requests and were tested by microcytotoxicity and WBSSP. Ankylosing spondylitis was clinically indicated in 79 of these cases.Microcytotoxicity was performed on cells after positive selection with magnetic beads (Dynabeads; Dynal, Oslo, Norway) using conventional techniques. SAMPLE PREPARATION Whole bloodSamples were mixed on a rotating mixer for one hour. An aliquot of 0.5 µl was removed and mixed with 6 µl of formamide (Sigma, St Louis, USA) and 3.5 µl of water and incubated at 95°C for five minutes. The final concentration of formamide in the PCR mix was 12%. This had bee...

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