Wednesday, May 28, 2008

What is Loin Pain Hematuria Syndrome?

by Marc F. Brazie, MD
Division of Nephrology
University of Maryland Medical Center, Baltimore, MD

What is Loin Pain Hematuria Syndrome (LPHS)?
LPHS is a rare kidney disorder causing attacks of severe flank pain and blood in the urine.

Who gets LPHS?
LPHS was first reported in three patients in 1967 who were found to have recurrent attacks of severe flank pain and blood in the urine (hematuria) in whom no other explanation could be found [2]. Since that time, it has been reported in several hundred people worldwide, although it is likely that there are many more unreported cases. It is more common in women (70% of all cases) [3-5], and has been seen mostly in the United States, Great Britain, Australia, and Canada, suggesting a white predominance. While it can start at almost any age, most patients will first develop symptoms in their 20’s [6].

How do I know if I have LPHS?
The predominant features of LPHS are recurrent flank pain and blood in the urine. The pain can occur on only one side or both, and may radiate to the abdomen, groin, or inner thigh. Pain episodes may be associated with low-grade fevers and a burning discomfort with urination. The blood in the urine may be overt (called “macroscopic hematuria”), or only detectible on a urine dipstick test or by examining the urine through a microscope (called “microscopic hematuria”). Up to 47% of patients with LPHS also have a history of kidney stones [7], but stones must be absent during pain episodes for LPHS to be diagnosed.

What causes LPHS?
As LPHS is a rare disorder, not much is known about the underlying causes. It is thought that there may be a problem with the glomerular basement membrane (GBM), which is the blood “filter” in the kidney, causing bleeding into the kidney tubules. These tubules can then become blocked by the blood cells, causing swelling and increased pressure in the kidney. This in turn leads to stretching of the outer layer of the kidney, called the “capsule,” and pain. Indeed, studies examining biopsies of patients thought to have LPHS have shown that in over 50% of patients, the GBM is abnormally thick or thin [7].

What should I do if I think I might have LPHS?
There are many disorders that can cause flank pain and blood in the urine, and as there is no specific test to confirm LPHS, it is considered a diagnosis of exclusion. It is very important to have a thorough evaluation by a kidney doctor (nephrologist) to be sure there is no other cause for the symptoms. This evaluation may involve laboratory tests, radiology studies, or even a kidney biopsy.

What can be done for LPHS?
Again, as LPHS is a rare disorder, it is not clear what the optimal treatment is. What is known is that patients with LPHS tend to have normal kidney function, which does not deteriorate over time. Thus, treatment is aimed at pain control and improvement in quality of life. Multiple therapies have been tried, all with mixed results. These include:
• Medications such at angiotensin-converting enzyme inhibitors (a family of blood pressure medicines which reduce the pressure in the kidney and have been shown to be of benefit to some patients [8]), non-steroidal anti-inflammatory drugs (such as ibuprofen, naproxen, or ketorolac), and narcotic pain medications.
• Nerve block procedures to decrease the pain signal from the effected kidney, and
• Surgery to strip the nerves from the kidney, “autotransplant” the kidney (in which it is removed from its normal position and reinserted in the lower abdomen – this has been shown to relieve pain in up to 70% of patient in some reports [3,4]), or in extreme cases, remove the kidney altogether.

It is best to discuss all the treatment options with your doctor, and ideally as part of a “multidisciplinary” approach involving primary care doctors, nephrologists, psychiatrists, and chronic pain specialists.

1. Dube GK, Hamilton SE, Ratner LE, Nasr SH, Radhakrishnan J. Loin pain hematuria syndrome. Kidney Int. 2006; 70: 2152-2155.
2. Little PJ, Sloper JS, deWardener HE. A syndrome of loin pain and haematuria associated with disease of peripheral renal arteries. Q J Med. 1967; 36: 253-259.
3. Sheil AG, Chui AK, Verran DJ et al. Evaluation of the loin pain/hematuria syndrome treated by renal autotransplantation or radical renal neurectomy. Am J Kidney Dis. 1998; 32: 215-220.
4. Chin JL, Kloth D, Paulter SE, Mulligan M. Renal autotransplantation for the loin pain-hematuria syndrome: long-term followup of 26 cases. J Urol. 1998; 160: 1232-1235.
5. Greenwell TJ, Peters JL, Neild GH, Shah PJ. The outcome of renal denervation for managing loin pain haematuria syndrome. BJU Int. 2004; 93: 818-821.
6. Weisberg LS, Bloom PB, Simmons RL, Viner ED. Loin pain hematuria syndrome. Am J Nephrol. 1993; 13: 229-237.
7. Spetie DN, Nadasdy T, Nadasdy G, et al. Proposed pathogenesis of idiopathic loin pain-hematuria syndrome. Am J Kidney Dis. 2006; 47: 419-427.
8. Hebert LA, Betts JA, Sedmak DD, et al. Loin pain-hematuria syndrome associated with thin glomerular basement membrane disease and hemorrhage into renal tubules. Kidney Int. 1996; 49: 168-173.

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