Pharmacologic treatment of kidney stones: Current medication and pH monitoring

Nephrolithiasis is a globally prevalent urologic condition associated with significant morbidity and patient discomfort. Current management of kidney stones includes both surgical and pharmacologic interventions. Though surgery may be necessary under certain circumstances, pharmacologic treatment is a more affordable, readily available, and a less invasive option for patients. A comprehensive scoping review was conducted to summarize the available literature on the pharmacologic strategies for managing the predominant stone types including calcium oxalate, calcium phosphate, uric acid, struvite, and cystine stones. Central to these therapeutic approaches is the regulation of factors such as urine pH, stone crystallization, and patient metabolics that precipitate stone development and growth. This review highlights the pharmacological options available for treating each kidney stone type, emphasizing the importance of patient tailored medical management that should be considered by every physician.

Motivators, resources and barriers in voluntary international migration of the elderly: The case of Israel-bound aged

A conceptual model was developed and tested to identify personal and situational factors which differentiate successful from unsuccessful planners of voluntary long-distance moves among the elderly. Potential migrants to Israel were identified at their point of origin and followed-up to ascertain whether they actually moved. This group generally shared a desire for a more challenging lifestyle and for opportunities to help others. A comparison group of movers (N = 97) revealed that 'push' and 'pull' factors in the environment of destination were far more important in differentiating these two groups than were factors in the environment of origin. Attachments, personal ties and familiarity with the new environment also emerged as significant predictors of moving. Selective evaluations of advantages of the new environment and obstacles to the move also differentiated movers from non-movers. Being married and in good health served as useful resources to facilitate the move. ka]Key Words kb]cross-national migration kb]voluntary relocation kb]elderly migration kb]migrant characteristics kb]environments kb]migration.

Economic transition should come with a health warning: the case of Vietnam

STUDY OBJECTIVE

s: To assess the affordability of health care to poor rural households in Vietnam under conditions of transition from a planned to a market economy and, in light of other transitional experience, inform policy on increasing access of the poor to affordable care of acceptable quality.

DESIGN

Observational study by cross sectional socioeconomic survey, longitudinal healthcare seeking survey, and qualitative semi-structured interviews and focus group discussions; qualitative follow up over six years.

SETTING

Four rural communes in north of Vietnam between 1992 and 1998. SURVEY PARTICIPANTS: 656 households (2995 people) selected by systematic random sampling.

MAIN RESULTS

Compared with non-poor households, poor households had significantly lower average per capita rates of healthcare consultation and expenditure (p<0.01 in both cases). Poor households delayed and minimised healthcare seeking, especially of expensive hospital services. Two thirds of average healthcare spending by poor households was on relatively inexpensive but frequent acts of local ambulatory care. The poor restrained their healthcare seeking but not in proportion to income: for households reporting illness, the average proportion of income devoted to health care was 21.9% for the poor compared with 8.2% for the non-poor (p<0.01). To meet healthcare costs, many poor households reduced essential consumption, sold assets and incurred debt, threatening their future livelihood.

CONCLUSIONS

In the short-term the poor need exemption from public sector user fees in both primary and hospital care. In the longer run the government budget and prepayment schemes should replace direct user charges in healthcare finance. Transitional economies like Vietnam should preserve the public health services built up under the planned economy. Market reforms that stimulate growth in the economy appear inappropriate to reform of social sectors.

Three new DP alleles identified in a study of 800 unrelated bone marrow donor-recipient pairs

HLA-DP genotyping of 800 unrelated donor-recipient pairs in phase 5 of a retrospective analysis of unrelated bone marrow transplantation, sponsored by the National Marrow Donor Program (NMDP), has identified two new DPB1 alleles (DPB1*8701 and DBP1*8801) and one new DPA1 (DPA1*0108) allele. Sequencing confirmed that all three of these new alleles represent novel combinations of previously described sequence motifs, reinforcing the notion that "gene conversion-like" events play an important role in generating HLA allelic diversity. The identification of these new alleles brings the total number of DPA1 alleles to 20 and the total number of DPB1 alleles to 94.

From cooperation to competition in national health systems--and back?: impact on professional ethics and quality of care

Ethical behaviour in health workers is the jewel in the crown of health services. Health system policies need to nurture a professional service ethic. The primary health care policy envisioned a national health system led by the public sector and based on a philosophy of cooperation. A common theme of 'health sector reform' in OECD countries, introduced in the context of neoliberalism, has been the use of 'managed competition' to increase efficiency. Some countries that flirted with health system competition have returned to cooperation. Market relationships tend to be oppositional and to stimulate self-seeking behaviour. Health system relationships should encourage patient and community centred behaviour. The World Bank and bilateral donors have exported health sector reform theories from the north to the south, involving privatization and marketization policies. This is despite the lack of evidence on their desirability or feasibility of implementing them. Private health care has increased in many developing countries, more as a result of economic crisis and liberalization than specific health sector reforms. Much of this private practice is unlicensed and unregulated, and informal privatization has had a damaging effect on health worker ethics. The lead policy should be reconstruction of the public health system, involving decentralization, democratization and improved management. Commonsense contracting of an existing private sector is different from a policy of proactive privatization and marketization. Underlying the two approaches is whether health care should be viewed as a human right best served by socialized provision or a private good requiring governments only to correct market failures and ensure basic care for the poor. It is a matter of politics, not economics.

Recipient tumor necrosis factor-alpha and interleukin-10 gene polymorphisms associate with early mortality and acute graft-versus-host disease severity in HLA-matched sibling bone marrow transplants

The proinflammatory cytokine tumor necrosis factor-alpha (TNF-alpha) is strongly implicated in graft-versus-host disease (GVHD) and other acute bone marrow transplant (BMT) complications. The antiinflammatory interleukin-10 (IL-10) antagonizes TNF-alpha and reduces GVHD. We previously showed association of recipient TNF (TNFd) and IL-10 (IL-10(-1064)) gene polymorphisms with acute GVHD severity in matched sibling BMT using only cyclosporin A monotherapy. The current study tested association of GVHD with TNFd and IL-10(-1064/-1082) polymorphisms in a large cohort (144 matched sibling donor/recipient pairs) given both cyclosporine A (CyA) and methotrexate (MTX) prophylaxis. Genotype results were correlated with acute and chronic GVHD and mortality. Patients homozygous for the TNFd microsatellite allele 3 had higher early mortality: 23.7% of TNFd3/d3 homozygotes died before day 30, compared with 6.80% of non-d3/d3 recipients (P =.013). Recipients possessing longer IL-10(-1064) microsatellite alleles developed more severe acute GVHD: 22.3% of recipients possessing alleles 12 to 15 developed grade III to IV GVHD, versus 3.92% of those with smaller alleles (P <.01). Other recipient or donor genotypes tested did not significantly affect GVHD or mortality. We conclude that recipient TNFd and IL-10(-1064) polymorphisms associate with early mortality and severe acute GVHD in matched sibling BMT with dual prophylaxis. This supports the hypothesis of genetic predisposition towards GVHD and other BMT complications other than histocompatibility antigen disparity.

Four new DP alleles identified in a study of 500 unrelated bone marrow donor-recipient pairs

HLA-DP genotyping of 500 donor recipient pairs in a retrospective analysis sponsored by the National Marrow Donor Program (NMDP) identified four new DP alleles, two DPB1 and two DPA1. DNA sequencing confirmed that DPB1*8001 and *8101, each found in a single individual, are novel combinations of previously described sequence motifs in the six variable regions of DPB1. DPA1*02014, found in two individuals, is identical to DPA1*02011 except for a novel silent substitution, a G to A transition at the third position of codon 14. DPA1*01032, found in one individual, is identical to DPB1*01031 except for a silent G to A transition at the third position of codon 20. The identification of these novel alleles brings the total number of reported DPB1 alleles to 85 and DPA1 alleles to 15.

Familial ureteral abnormalities syndrome: genomic mapping, clinical findings

Abnormal development of the ureter during embryogenesis, when occurring in multiple family members, appears to be a genetically determined defect with autosomal dominant inheritance and high penetrance, which can lead to significant kidney damage, renal failure, and death. We have studied 48 individuals within a large kindred in which ureteral-related abnormalities (including vesicoureteral reflux, ureteropelvic junction obstruction, duplicated ureters, and medullary sponge kidney) were segregated. Family members who had not had previous diagnostic studies were evaluated for presence or absence of ureteral abnormalities and we attempted to map the locus for this familial ureteral abnormalities syndrome (FUAS). These studies identified 11 asymptomatic individuals, previously assumed to be unaffected, with minor abnormalities. When linkage analysis between the inheritance of ureteral abnormalities and six marker loci glyoxalase I (GLO- ), major histocompatibility antigens (HLA-A, B, and DR/DQ), D6S288, and factor XIII antigen (F13A1) on the short arm of chromosome 6 was performed, the lod scores significantly rejected linkage over a 77.1-cM distance. These findings are in contrast to previous data suggesting linkage between the presence of ureteral abnormalities and HLA, and indicate the possibility of genetic heterogeneity of FUAS.

Identification of the DRB1*1313 allele in a sibling pair

Sequence-specific oligonucleotide probe hybridization (PCR/SSOP), which is now routinely used in HLA laboratories to type for alleles of the class II loci, can also detect the presence of previously unknown alleles. In the course of clinical typing for DRB1, we identified two samples with probe hybridization patterns appropriate for DRB1*1313, a previously submitted sequence that had been withdrawn. Direct sequencing showed that the two individuals carried an allele with an exon 2 sequence identical to that previously submitted for DRB1*1313.

Six new DPB1 alleles identified in a study of 1,302 unrelated bone marrow donor-recipient pairs

Six new DPB1 alleles were identified by PCR-SSOP methodologies in the course of a retrospective study of the role of HLA matching in the outcome of unrelated donor bone marrow transplantation. Sequencing confirmed that five of these alleles (DPB1*5901, *6801, *7101, *7201, and *7301) represent novel combinations of previously described sequence motifs in the variable regions of DPB1; the sixth (DPB1*7001) appears to result from a novel point mutation. These data support previous observations which suggest that multiple mechanisms, including segmental exchange and mutation, appear to be responsible for generating sequence diversity at the DPB1 locus. The extremely low discrepancy rate of 0.1% between the two laboratories which typed the samples, and the ability to predict the new sequences from probe hybridization patterns, indicate that SSOP is an accurate and efficient method for studying polymorphism at DPB1.

Lack of correlation of MLC reactivity with acute graft-versus-host disease and mortality in unrelated donor bone marrow transplantation

Acute graft-versus-host disease (AGvHD) is a significant cause of morbidity and mortality in patients receiving a bone marrow transplant from an unrelated donor, and in an effort to reduce this problem, donors are selected for the least possible HLA incompatibility with the recipient. Selection criteria have included minimal incompatibility for the HLA-A, -B, and -DR loci and low reactivity in mixed lymphocyte culture (MLC); however, the value of MLC reactivity for prediction of development of AGvHD has been questioned. We therefore examined the correlation of MLC reactivity with AGvHD in recipients of unrelated bone marrow transplants. Reactivity in the GvH direction was assessed as relative response (RR) of donor lymphocytes to recipient stimulator lymphocytes. In 126 transplanted pairs with technically satisfactory MLC tests, the RR was divided into quartiles (0-1, 2-5, 6-16, and 17-117% RR). HLA-DRB1 incompatibilities were more frequent in the highest quartile (P < 0.001); there were no significant differences among quartiles in donor or recipient age, diagnosis, or frequency of HLA-A or -B incompatibility. Incidence of AGvHD during the first 100 days post-transplant was assessed by Kaplan-Meier analysis. There was no significant difference in incidence of AGvHD among quartiles for the entire group of 126 pairs, for a subset with hematologic malignancy, for a subset selected by a more stringent standard for "technically satisfactory" MLC, or for a subset matched for A, B, and DRB1. The MLC response of donor lymphocytes to recipient stimulator lymphocytes is thus not predictive of development of AGvHD in our patient population receiving unrelated donor bone marrow. Since there was no difference in mortality related to high and low MLC responses, our data also suggest that MLC results are not predictive of survival in this population.

Does re-exposure to mismatched HLA antigens decrease renal re-transplant allograft survival?

We analyzed 420 kidney retransplants at the University of Minnesota, 87 of which did and 333 which did not share HLA mismatches with the previous transplant. There was no difference in outcome. We conclude that exceptions to routine HLA matching policies do not have to be made for kidney retransplants.

OBJECTIVE

To determine if the kidney graft functional survival rate for retransplants is influenced by presence of HLA mismatches in common with the previous (failed) transplant.

SUMMARY BACKGROUND DATA

Kidney retransplants have a lower function rate than primary grafts. An anamnestic response to HLA antigens shared with the previous donor could be one factor responsible, but reports in the literature are conflicting.

METHODS

Of 420 kidney retransplants with HLA information done at the University of Minnesota, 87 shared > or = 1 HLA antigens specifically mismatched with the previous donor (63 cadaver and 24 living donor retransplants), while 333 did not (247 cadaver, 86 living donor). Patient and graft survival rates were calculated by life-table analysis for recipients with vs. without repeat mismatches, with the significance of differences determined by the Lee-Desu statistic.

RESULTS

Patient and kidney graft retransplant survival rate curves were not significantly different (p > or = 0.41) for those exposed or not exposed to the same HLA mismatches as before. At 2 years, 70% vs. 61%, respectively, of cadaver grafts and 71% vs. 78%, respectively, of living donor grafts were functioning.

CONCLUSIONS

The probability of a successful outcome with a kidney retransplant is no different for patients who do than for those who do not receive an organ sharing HLA mismatches with the previous donor. Exceptions to routine HLA matching policies do not need to be made for kidney retransplants.

HLA class II genes associated with REM sleep behavior disorder

Twenty-five white men with rapid eye movements (REM) sleep behavior disorder, but without narcolepsy, underwent HLA class II antigen typing: 84% (N=21) were DQwl (DQB1*05,06) positive (28% [N=7] were DR2 positive); DQB1*0501 (N=9) and DQB1*0602 (N=7) were the most common phenotypes. The 84% DQwl rate in men with REM sleep behavior disorder was significantly greater (p=0.015) than the 56% DQwl rate found in a local white comparison group (N=66), and was greater than the 39 to 66% DQwl rates published for 12 white groups (N=40-418/group). Thus, another disorder of REM sleep dysregulation (besides narcolepsy) appears to be strongly associated with specific HLA class II genes.

Cooperative medical schemes in contemporary rural China

Improvements in rural health care in China in the 1950s, 1960s and 1970s were largely due to the development of cooperative medical schemes (CMSs) and the establishment of a three-tier rural health network. Since the economic reforms were instituted in the late 1970s, the financing and delivery of rural health services have seen many changes, some positive, others not. Most CMSs have collapsed. In the absence of CMSs, the rural population has to pay for health care out-of-pocket and poor families have greater difficulty in getting access to essential health care. In the meantime, emphases of health services have tended to shift from lower to higher levels, from preventive to curative services, and from planning and management to market forces. This paper outlines the evolution of CMSs, reasons for their collapse, and their likely impact on rural health services. The main focus is on the development of a new generation of rural cooperative health care schemes, given their importance in the process of consolidating the rural three-tier health network after the impact of the economic reforms: the characteristics of some schemes, the apparent conditions for success, and government policy towards the development of cooperative health care financing are presented.

Unrelated donor bone marrow transplantation: influence of HLA A and B incompatibility on outcome

We have studied the outcome of 211 consecutive unrelated donor (URD) bone marrow transplants (BMT) performed at the University of Minnesota (Minneapolis, MN) between May 1985 and December 1992. Ninety patients (43%) received marrow matched serologically at HLA A, B, and DR loci; 86 (41%) received marrow with a major and 32 (15%) marrow with a minor serologic mismatch at the HLA A or B locus. Multivariate analysis revealed that older age had an adverse effect on survival. In younger (age less than 18 years) recipients, survival after fully matched (A, B, and DR sub-type) or major mismatched (A or B locus), DR subtype-matched donor BMT was not significantly different (P = .4; survival: 53% v 41%, respectively, at 3 years). For adults, survival after matched donor BMT was significantly better than that with mismatched donors (P < .01; survival: 30% v 10%, respectively, at 3 years). Formal quality of life assessment by telephone interview demonstrated similar functional status in survivors of URD and related donor (RD) BMT at least 2 years post-BMT. URD BMT provides effective therapy for a variety of lethal hematopoietic diseases that rivals outcome of RD transplant in some cases. Use of URD marrow with a major mismatch at one HLA A or B locus is well tolerated in young, but not in older, recipients. These observations should be used to improve donor selection and counseling for URD BMT candidates.

Iatrogenic arterial dissection: treatment by percutaneous transluminal angioplasty

Iatrogenic arterial dissection may require intervention, depending on the severity of resulting stenosis and the degree of symptoms. We present 5 cases of iatrogenic arterial dissection: 1 with dissection of the lower abdominal aorta, common iliac artery, and external iliac artery, and 3 with external iliac artery dissections, all managed with percutaneous transfemoral transluminal angioplasty; and 1 with dissection of the superior mesenteric artery with angioplasty performed by the translumbar approach. Four of the 5 patients had no additional therapy; 1 patient eventually underwent surgery for an asymptomatic residual pseudoaneurysm seen on abdominal computed tomography. Angiographic follow-up in 2 patients demonstrated persistent improvement in stenosis, 1 at 2 weeks after angioplasty, and the other, 6 weeks following angioplasty. None of the 5 patients required further therapy for recurrence of symptoms on clinical follow-up obtained up to 1 year after angioplasty. Though the incidence of recurrent arterial stenosis following angioplasty for dissection may be greater than that incurred after intravascular stent placement or surgery, angioplasty may be effective, and has the advantage of being less expensive than both of these treatment modalities, and more widely available and applicable than intravascular stents.

Hypoxic pulmonary hypertension: changes in platelet size and number

Circulating platelets have been implicated in the hypoxic pulmonary pressor response. This study was undertaken to assess the effects of acute hypoxia-induced pulmonary hypertension on platelet volume and number across the pulmonary circulation in anesthetized newborn lambs. Seven animals were instrumented for measurement of pulmonary vascular resistance. All measurements were made during normoxia and after 5 and 30 minutes of hypoxia (10 to 12% oxygen breathing). Hypoxia caused a doubling of the pulmonary vascular resistance. During hypoxic vasoconstriction, platelet volume decreased rapidly while traversing the lung but was not affected on return to the lung after traversing the systemic circulation. Platelet numbers were unchanged on leaving the lung but were decreased on entering the lung during hypoxia. Our data are consistent with the release of platelet contents in the lung during hypoxic pulmonary hypertension.

Serology, restriction fragment length polymorphism, and sequence analysis of a unique HLA class II antigen, DR5x6

We analyzed a new class II HLA haplotype, which we have designated DR5x6, by serology, restriction fragment length polymorphism (RFLP), and sequence analysis. As the name DR5x6 implies, the antigen is serologically closely related to both DR5 and DRw6. RFLP analysis of this haplotype suggests a close similarity with DRw11 haplotypes. The DNA sequences encoded by the second exon of its DRB1, DRB3, and DQB1 genes were also determined. Comparison of these sequences with those of alleles at these loci in other haplotypes suggests that this haplotype could have evolved from a DRw11 ancestor haplotype (DRw11-DRw52b (Dw25)-DQw7) by means of: (a) a gene conversion at the DRB1 locus involving DRw8 (Dw8.3) as the sequence donor, plus a point mutation or a gene conversion involving DR4-Dw4; and (b) a recombination event by which this haplotype would have acquired the DRw5a (Dw24) allele at the DRB3 locus.

Health sector planning led by management of recurrent expenditure: an agenda for action-research

Health services in developing countries face a crisis of recurrent costs. Far from being able to fund primary health care (PHC) developments, governments now have difficulty in keeping existing health services in operation. This article proposes an approach to the problem based on the proactive planning and management of recurrent health expenditure. The system addresses existing services as well as future plans and allows explicit trade-offs to be made in resource allocation. This may be termed 'recurrent-expenditureled planning'. The article describes a diagnostic health sector review, which incorporates a recurrent expenditure profile in four planes: by type of provider, source of finance, level of care and recipient population group. A fifth dimension of time trends for certain expenditure categories can be added. The steps of a strategic planning cycle for health services resources are then described, which allows health service strategies to be tested for broad economic feasibility. It also results in the establishment of resource targets that can act as benchmarks against which actual levels of funding can be compared. The targets help to maintain sectoral priorities in resource allocation even in times of economic constraint and to channel funds preferentially to localities and facilities in greatest need. The system calls for innovations in the methods of health planning and financial management in the health sector. Implementation will require health systems action-research at the country level. The essential purpose is to promote PHC policy-led resource allocation and use. No amount of planning can substitute for political action to realize 'health for all', but this system provides technical support to the political forces in favour of distributive PHC policies.

HLA and genetics of IDDM. Holism vs. reductionism?

Analysis of HLA-associated susceptibility to insulin-dependent diabetes mellitus (IDDM) has largely focused on identifying the susceptibility gene. Adherents of a countertrend have long suggested the importance of analysis of HLA haplotypes (combinations of alleles on 1 chromosome) rather than individual genes. Accumulating data suggest that the relationship between IDDM susceptibility and HLA is much more complex than a single susceptibility gene. Consideration of this question should include the possibilities that 1) more than one HLA gene is involved in determining susceptibility or resistance; 2) different alleles of the same gene may be associated with different pathogenetic mechanisms; and 3) different susceptibility-associated haplotypes, even if they share an allele at an IDDM-relevant locus, may behave differently in IDDM. A better understanding of the genetics, and perhaps the pathogenesis, of IDDM may be obtained by following up the clues offered by analysis of the association of HLA haplotypes (rather than individual alleles) with one another, with clinical features of IDDM, and with possible non-HLA-linked susceptibility factors.

Genetic relationships between type I and type II diabetes mellitus

We propose that at least certain subsets of Type I and Type II diabetes share factor(s) responsible for genetic susceptibility. The data presented here to support this contention include: 1. A significantly increased cumulative risk (CR40) to age 40 for Type I diabetes in sibs of probands in families with a Type II diabetic parent (Type II diabetic parent: CR40-24.7 +/- 10.7%; normal parent: CR40 = 7.5 +/- 2.0%, x2 = 12.8, p less than 0.0005). 2. The relative risk (RR) for HLA DR4 in Type I diabetic probands with a Type II diabetic parent is higher than in probands with normal parents (RR = 2.4). 3. The haptoglobin genotype 2-2 is increased in Type I diabetics with Type II parents and the sharing of both HLA and haptoglobin haplotypes in affected sib pairs is distorted with an excess sharing of both haplotypes.

Primary health care is viable

'Selective primary health care' and other recent vertical health strategies have been justified on the grounds that the broad primary health care (PHC) approach cannot be afforded by developing countries in the present constrained economic circumstances. This judgement is too sweeping. A simulated case example is presented, starting with baseline health expenditure data that are representative of the situation in many developing countries. It is assumed that real economic growth occurs and that government funding of health care is allowed to grow in parallel. Two annual growth rates are considered: 2 and 5 per cent. Two restrictive conditions are applied: none of the main health services is subjected to absolute cuts; and, additional funds from existing or new sources of finance are not considered. It is shown that, even with slow growth rates, substantial increases in the funding of priority (rural and PHC) services can be achieved if the growth in expenditures of lower-priority services is curtailed. Also, savings from improved health service efficiency can be channelled to priority services. The message is that the PHC approach is viable even with slow economic growth. What is required is the technical capacity to identify and plan resource flows in the health sector, and the political will to effect resource allocations according to PHC priorities. A strategic policy like PHC should not be 'adjusted' out of effective existence because of reversible economic problems. Rather, actions should be taken to reverse the adverse economic environment. International health-related agencies should continue to support countries to develop national health systems based on PHC, and should campaign for reforms in the world economy to create at least the minimum economic conditions necessary for PHC implementation.

Comparison of DR beta 1 alleles from diabetic and normal individuals

Insulin-dependent diabetes (IDD) is positively associated with HLA-D proteins. A critical question is whether or not sequence differences within the HLA-D coding region are the same or different in diabetics and normal individuals of the same haplotype. We have isolated both DR beta 1 alleles from a Dw4/LD MN2 cDNA library and compared them to DR beta 1 genes isolated from normal individuals of the same Dw phenotype. We found no nucleotide differences in the coding region between the normal and diabetic alleles of DR beta 1 suggesting to us that DNA differences other than the DR beta 1 coding region may account for the observed association of HLA-D and diabetes.

DR2+ haplotypes in insulin-dependent diabetes: analysis of DNA restriction fragment length polymorphisms

Insulin-dependent diabetes (IDD) is strongly associated with certain HLA class II (Ia) antigens. The frequency of DR2 is significantly reduced in IDD; among DR2+ patients, the frequency of the subtype specificity Dw2 defined with homozygous typing cells (HTCs) is significantly reduced compared to DR2+ controls, and the specificity LD-MN2, which we have defined using primed lymphocyte typing reagents, is significantly increased. We have studied DNA restriction fragment length polymorphisms (RFLP) of DR2-LD-MN2+ individuals and homozygous typing cells carrying specificities antigenically related to LD-MN2. Using a number of different restriction enzymes, a characteristic pattern of fragments could be defined for DR2-LD-MN2 using both DQ beta and DR beta cDNA probes. This pattern was shared with some but not all of the antigenically related HTCs, and was distinct from that of DR2-Dw2. The RFLP pattern of DR2-LD-MN2 obtained with the DQ beta probe is identical, except for one band, to that of DR1-Dw1, suggesting that at least some part of the DQ region is identical in these two haplotypes. These results indicate that analysis of RFLP patterns can be used to help identify the genetic regions and, eventually, genes most important in the association of HLA and IDD.

DNA restriction fragment length polymorphisms characteristic for Dw subtypes of DR2

DNA restriction fragment length polymorphisms (RFLP) can be easily demonstrated in DNA of cells expressing different DR specificities when class II cDNA probes are used for hybridization. Previous studies of DR4+ homozygous typing cells (HTCs) carrying different Dw subtypes, however, detected no RFLP correlating with subtypes. In contrast, we report here Southern blotting studies of DR2+ HTCs carrying different subtypes which showed RFLP patterns characteristic for each subtype, using both DR beta and DQ beta probes and several restriction enzymes. The RFLP between subtypes of DR2 was, however, appreciably lower than that found between DR specificities.

Dw subtypes of DR4 in rheumatoid arthritis: evidence for a preferential association with Dw4

We have determined the frequency of the DR4-associated Dw subtypes, defined by homozygous typing cells, in a group of rheumatoid arthritis (RA) patients on second-line drug therapy. The frequency of DR4 in these patients was 86%. Among Caucasians, the frequency of Dw4 in the DR4-positive patients was significantly increased (68%) as compared to DR4-positive normal individuals (46%; p less than 0.025). Dw4, as compared to the other DR4 subtypes tested, may also be associated with more severe disease as judged by indices of functional impairment and joint damage. In a small subgroup of non-Caucasian (black and Native American) patients, the Dw13 (DB3) subtype of DR4 was often seen, suggesting that RA may have different Dw associations in different ethnic groups.