Red-cell alloimmunization

Morbidity and mortality due to Rhesus antibodies in pregnant women's serum have steadily declined because of various factors which include, implementation of routine antenatal anti-D prophylaxis and development of non-invasive investigations for monitoring Rhesus affected pregnancies. Because at present this condition is so rare, any case of red-cell alloimmunization should be managed in liaison with a specialist in foetal medicine. Unlike the first immunized pregnancy, maternal antibody titres are not predictive of foetal risk in any subsequent pregnancies. Serial peak middle cerebral artery velocities using Doppler can be used in these pregnancies to detect foetal anaemia. Foetal blood type can now be determined by new techniques to detect free foetal DNA in maternal plasma. In selected cases depending on the gestational age of foetus intrauterine transfusion is necessary through ultrasound directed puncture of the umbilical cord with the direct intravascular infusion of red blood cells. Perinatal survival rates of more than 90% have been reported.     

Percutaneous transluminal coronary angioplasty after non-Q-wave acute myocardial infarction

The value of percutaneous transluminal coronary angioplasty (PTCA) for ischemia after a non-Q-wave acute myocardial infarction (AMI) was assessed prospectively in 33 consecutive patients. In 30 patients the indication for the procedure was post-AMI angina and 3 patients underwent PTCA for silent ischemia. A total of 43 lesions were attempted at 63 +/- 94 days after the non-Q-wave AMI. Primary PTCA success was obtained in 30 (91%) patients and no major complications occurred. Angiographic evaluation was performed either for symptoms or for protocol (7 +/- 1 months after PTCA) in 28 (93%) of the 30 patients with successful PTCA, but 2 patients (7%) who were asymptomatic refused the repeat angiogram. Twenty (71%) had no restenosis and 8 (29%) had restenosis. Of these, 5 patients with restenosis underwent a successful repeat PTCA (6 +/- 1 months after the initial procedure). At the last clinical follow-up (17 +/- 8 months), 2 of the 30 (7%) patients successfully dilated presented with stable angina despite medical treatment, whereas the rest (93%) remained asymptomatic. During the study period no patient died, had an AMI or required coronary artery bypass grafting. Thus, selected patients with ischemia after a non-Q-wave AMI, a "high-risk population," can be effectively treated with PTCA with an initial success rate and angiographic restenosis rate similar to that of the general PTCA population and appear to have sustained symptomatic benefit remaining free of subsequent cardiac events.     

Pulmonary sarcoidosis in a patient with ankylosing spondylitis treated with infliximab

We present a case of a 34 year-old male diagnosed with ankylosing spondylitis. After two years of treatment with infliximab, the patient developed a clinical picture compatible with stage II thoracic sarcoidosis. These findings resulted in the interruption of infliximab therapy. The patient was not administered new treatment since respiratory function testing did not confirm harmful repercussions. After a follow-up of 1 year, the patient is asymptomatic and radiologic tests show complete resolution of pulmonary infiltrates and mediastinal and bilateral hilar lymphad- enopathy.     

Are we prescribing multiple courses of antenatal corticosteroids? A survey of practice in the UK

A postal questionnaire concerned with prescribing antenatal corticosteroids was sent to one named clinician at each of 279 obstetric units in the UK. They were asked whether their unit prescribed repeated courses, the indications for which these would be prescribed, the interval between courses, the drugs and regimens used and whether they would be willing to participate in a proposed randomised controlled trial. The response rate was 75%. Of the respondents, 98% prescribed repeated courses; the indications most commonly cited by units who prescribed steroids were prelabour spontaneous rupture of membranes (84.2%), and suspected preterm labour (81.8%). 70.6% of units were willing to participate in the proposed trial.     

Association analysis of drug metabolizing enzyme gene polymorphisms in HIV-positive patients with co-trimoxazole hypersensitivity

The use of co-trimoxazole in HIV-positive patients has been associated with a high frequency (40-80%) of hypersensitivity reactions. This has been attributed to the bioactivation of the sulphonamide component, sulphamethoxazole (SMX), to its toxic hydroxylamine and nitroso metabolites. The aim of this study was to determine whether functionally significant polymorphisms in the genes coding for enzymes involved in SMX metabolism influence susceptibility to SMX hypersensitivity. HIV-positive patients with (n = 56) and without (n = 89) SMX hypersensitivity were genotyped for allelic variants in CYP2C9, GSTM1, GSTT1, GSTP1 and NAT2 using polymerase chain reaction (PCR) and/or PCR-restriction fragment length polymorphism analysis. The CYP2C9*2/*3 genotype and CYP2C9*3 allele frequencies were nine- and 2.5-fold higher in the hypersensitive group compared to non-sensitive patients, respectively, although they were not statistically significant when corrected for multiple testing. There were no differences in the frequencies of the GSTM1 and GSTT1 null genotypes, and the slow acetylator genotype, between hypersensitive and non-sensitive patients, while GSTP1 frequency was lower (although non-significant) in the hypersensitive group [21% versus 32%, odds ratio (OR) = 0.5, Pc = 0.24]. Comparison of the genotype frequencies in HIV-positive and -negative patients showed that the NAT2 slow acetylator genotype frequency in the HIV-positive patients (74%) was significantly (Pc = 0.0003, OR = 2.3) higher than in control subjects (56%). Our results show that genetic polymorphisms in drug metabolizing enzymes are unlikely to be major predisposing factors in determining individual susceptibility to co-trimoxazole hypersensitivity in HIV-positive patients.