Immunohistochemical study for the diagnosis of Alport's syndrome.

BACKGROUND: Alport's syndrome (AS) is the most common cause of inherited glomerular disease in Thailand. The majority of cases show X-linked inheritance, which is caused by mutations in the gene coding for the alpha5 chain of type IV collagen in the glomerular basement membrane (GBM) and epidermal basement membrane (EBM). Such mutation usually leads to a reduction in protein amount, thus, immunohistochemical studies have been considered in diagnostic evaluation. OBJECTIVE: To study the expression of alpha[IV] collagen chains in the skin as an alternative approach to diagnose AS. MATERIAL AND METHOD: Eleven unrelated probands with proven AS, 7 relatives with abnormal urinalysis, 4 suspected individuals, and 8 normal controls were enrolled. A punch skin biopsy and immunofluorescence staining of the tissue specimens for alpha1, alpha3 and alpha5[IV] collagen chains was performed. RESULTS: The alpha5[IV] chain was absent in the EBM in all male AS patients while a discontinuing pattern was observed in all females except one. The findings are specific for AS with a sensitivity of 91%. Studies in relatives and suspected individuals also confirmed the advantage of this approach as demonstrated by the absence and discontinuation of alpha5[IV] staining in all males and females, respectively. We also analyzed their expressions in the kidney tissue and demonstrated abnormal alpha3 and alpha5[IV] staining in five of six samples. CONCLUSION: Immunohistochemical study of the skin should be used as a screening method in patients suspected of AS, as it is much less invasive. Moreover, it is a useful adjunct to conventional examination of biopsied renal tissue.

The efficacy of combined mefloquine-artesunate versus mefloquine-primaquine on subsequent development of Plasmodium falciparum gametocytemia.

An open randomized controlled study of mefloquine-artesunate and mefloquine-primaquine for the treatment of uncomplicated Plasmodium falciparum malaria was carried out in Kanchanaburi in the Saiyok District in western Thailand. Weekly parasite counts from thick and thin blood films were done for six weeks. The gametocyte carriage rate was calculated and compared between the two treatment groups. Gametocytes on presentation, recrudescent infection, and reinfection were the significant factors associated with subsequent development of gametocytemia. It is the increased propensity of recrudescent infections to produce gametocytes that drives drug resistance. The results of this study confirmed that the complete eradication of a sexual forms of P. falciparum by effective antimalarial treatment, but not by combination treatment with primaquine, is the most effective means to prevent subsequent gametocytemia.