A Blood Disorder You've Never Heard Of Could Be Silently Damaging Your Kidneys

People with myelodysplastic syndromes (MDS)—a rare blood disorder affecting bone marrow—face roughly double the risk of kidney function decline compared to those without the condition. A large Japanese study tracking over 1.6 million adults found that MDS independently predicted both sudden kidney problems and faster, ongoing loss of kidney function over time. The findings suggest that MDS should be recognized as a clinically relevant kidney risk condition warranting closer surveillance in routine medical practice.

What Are Myelodysplastic Syndromes and Why Do They Affect the Kidneys?

Myelodysplastic syndromes are a group of blood disorders in which the bone marrow doesn't produce enough healthy blood cells. While most people associate MDS with blood-related complications, this new research reveals that the kidneys are also a vulnerable target organ. The study, published in the Clinical Kidney Journal, analyzed administrative health claims and standardized checkup data collected between April 2014 and August 2024 across Japan.

Among the 1.6 million participants studied, only 901 individuals (0.05%) had MDS, but their kidney outcomes told a striking story. Over a median follow-up period of about three years, people with MDS experienced significantly higher rates of kidney function decline. The research team found that individuals with MDS had an adjusted hazard ratio of 2.28, meaning they were 2.28 times more likely to experience kidney problems—a statistically significant difference with high certainty.

How Much Faster Do Kidneys Decline in MDS Patients?

The study measured kidney function using estimated glomerular filtration rate (eGFR), a standard test that shows how well kidneys filter waste from the blood. In healthy people, eGFR typically declines very slowly with age. However, in people with MDS, the decline was noticeably accelerated. Those with MDS lost kidney function at a rate of 0.822 mL/min/1.73 m² per year, compared to 0.642 mL/min/1.73 m² per year in people without MDS—roughly 28% faster.

During the follow-up period, the MDS group experienced 3 cases of end-stage kidney disease (the most severe form requiring dialysis or transplant), 3 initiations of kidney replacement therapy, and 36 cases of at least a 30% decline in eGFR. While these numbers may seem small in absolute terms, they represent a substantially higher rate than would be expected in a group of similar size without MDS.

Who Is at Highest Risk?

The study revealed that people with MDS who developed kidney problems tended to share certain characteristics. Individuals in the MDS group were typically older (median age 68 years), more often male, and had higher rates of existing conditions including hypertension, diabetes, and proteinuria (protein in the urine). They also had lower baseline hemoglobin levels and lower starting eGFR values, suggesting their kidneys were already under stress.

The research team adjusted their analysis for these demographic factors and comorbidities to isolate the independent effect of MDS itself. Even after accounting for these other risk factors, MDS remained a powerful predictor of kidney decline, suggesting that something about the blood disorder itself—not just the associated conditions—drives kidney damage.

Steps to Monitor Kidney Health if You Have Myelodysplastic Syndromes

• Regular eGFR Testing: Ask your hematologist or primary care doctor to include estimated glomerular filtration rate testing in your routine blood work at least annually, or more frequently if recommended based on your baseline kidney function.
• Urine Protein Screening: Request urinalysis or urine protein testing to check for proteinuria, which is a warning sign of kidney stress and was more common in MDS patients who developed kidney problems.
• Blood Pressure Management: Work with your healthcare team to keep blood pressure well-controlled, since hypertension accelerates kidney damage and was present in a large proportion of MDS patients in the study.
• Coordinate Care Between Specialists: Ensure your hematologist and nephrologist (kidney specialist) are communicating about your condition, since MDS affects multiple organ systems and kidney monitoring may not be automatic in hematology-focused care.

The authors of the study emphasized the importance of these monitoring strategies, stating: "These results highlight the kidney as a clinically relevant target organ in MDS and underscore the importance of kidney function monitoring. Future studies incorporating genomics, cytokine profiling, and kidney histopathology are warranted to elucidate the underlying mechanisms".

What Does This Mean for MDS Patients Going Forward?

The findings don't mean that everyone with MDS will develop kidney disease. Rather, they suggest that kidney function monitoring should become a standard part of MDS care, similar to how blood counts and bone marrow assessments are already routine. The study's large size—involving over 1.6 million people—and robust methodology, including multiple sensitivity analyses and competing-risks modeling, give confidence in the results.

Researchers acknowledge that the exact biological mechanisms linking MDS to kidney damage remain unclear. The bone marrow disorder may trigger systemic inflammation, alter kidney blood flow, or cause direct cellular damage through mechanisms not yet fully understood. Future research incorporating genetic analysis, inflammatory marker profiling, and kidney tissue examination will help clarify why this connection exists and potentially lead to targeted preventive strategies.

For now, the takeaway is clear: if you have been diagnosed with myelodysplastic syndromes, discussing kidney health monitoring with your healthcare team is an important conversation to have. Early detection of kidney function decline can open doors to interventions that slow progression and preserve kidney health for as long as possible.