Early and late humoral rejection: a clinicopathologic entity in two times.

Humoral rejection is an important cause of early and late graft loss. The late variant is difficult to diagnose and treat. There is a close correlation between sclerosing nephropathy and anti-HLA antibodies. We analyzed 113 renal allograft recipients between August 2004 and April 2007. Acute humoral rejection was defined as acute graft dysfunction in presence of donor-specific antibodies (DSA) detected by flow panel reactive antibodies (PRA) and/or C4d positive pericapilary tubules (PTC) detected histopathologically by immunofluorescent or immunoperoxidase at less than 3 months postransplantation. Late humoral rejection was defined as dysfunction occurring after 3 months postransplantation with histopathologic glomerulopathy or vasculopathy and positive C4d PTC. We included all patients who were diagnosed with early or late graft dysfunction and underwent biopsy, all of which were examined for C4d. Four patients had acute humoral rejection treated with IVIG or plasmapheresis. The patient and graft survivals were 100% and serum creatinine averaged 1.7 mg/dL. Three recipients experienced late humoral rejection at 3 to 10 years posttransplantation All received high-dose IVIG; one also was treated with thymoglobulin. Immunosuppression was switched to tacrolimus, mycophenolate mofetil, and steroids. Only one patient recovered renal function; the others returned to dialysis. Among seven patients only one had an actual PRA (>20%) and three showed 10% to 20%. However, six had a positive historical PRA of 10% to 50%. In conclusion, Recognition of acute humoral rejection has contributed to graft rescue by controlling alloantibody production through new specific immunosuppressive therapies in contrast with the clinical response to acute therapy, treatment of a chronic entity has shown poor outcomes, probably because antibody mediated chronic graft damage is already present when the late diagnosis is established by biopsy.

[B-DR (HLA) linkage imbalance and transplants in Chile: a preliminary report]. / Desequilibrio de ligamento B-DR (HLA) y trasplantes en Chile: comunicación preliminar.

Linkage imbalance for the B and DR loci (HLA) was found in a Chilean sample of families where a member had been proposed for transplantation. The B7-DR2 and B14-DR1 haplotypes were significantly more frequent than expected. Most associations were those found in Caucasian populations.

HLA in Chileans with intrahepatic cholestasis of pregnancy.

A possible association between intrahepatic cholestasis of pregnancy (ICP) and human-leukocyte histocompatibility (HLA) antigens--used as genetic markers--was studied in 100 women with ICP compared to 100 multiparous women without a past history of the disease. Because we previously found a higher frequency of ICP in women with an overt Araucanian Indian descent than in Chilean Caucasoids, women from both ethnic groups were studied. Among the 37 specificities of the HLA system studied (17 of HLA-A, 16 of HLA-B, and 4 of HLA-C series), only HLA-BW16 showed a tendency to be more frequent in women with ICP rather than in control women. This finding appears to be related with ethnic origin and not ICP, HLA-BW16 was significantly more frequent in women with Araucanian Indian descent (43.4%) than in Chilean Caucasoids (16.3%) (p less than 0.01). The high frequency of HLA-BW16 in the predominantly Caucasoid population in Chile, in comparison with Caucasians in Europe and in North America, may be another indicator of their ethnic admixture with aborigine groups. The high frequency of HLA-BW16 reported in North American Indian-admixed groups (16%) suggests that HLA-BW16 may be a genetic characteristic common to some aboriginal populations in North and South America.

Inmunidad en fiebre tifoidea. / Immunity in thyphoid fever

El objetivo de esta experiencia consiste de diferentes parametros inmunologicos, humorales y celulares en un grupo de enfermos con fiebre tifoidea; asimismo, en la medida de lo posible, se trata de establecer alguna forma de relacion entre los cambios observados y la evolucion clinico bacteriologica

Distribution of HLA histocompatibility antigens, ABO blood groups and Rh antigens in alcoholic liver disease.

The distribution of 16 antigens of the HLA-A and 15 antigens of the HLA-B series of HLA system, the blood groups ABO, and Rh antigens were studied in 40 alcoholics with cirrhosis, 18 alcoholics without cirrhosis, and in normal control subjects. The group of alcoholics with cirrhosis showed a significantly high frequency of HLA-B13 (corrected P less than 0.01) when compared with normal subjects, while the frequency of HLA-B13 was similar to normal in alcoholics without cirrhosis. On the basis of these findings, its seems that the carriers of HLA-B13 are more susceptible to liver damage caused by alcohol. Both groups of alcoholics and the normal controls had a similar distribution of ABO blood groups and Rh antigens.